JP7056395B2 - Control device and its control method - Google Patents

Description

The present invention relates to a control device such as a programmable logic controller (hereinafter, also referred to as PLC).

Conventionally, in order to prevent data to be transmitted at each of two communication rates using the same frequency band from colliding with each other, it is known to provide a transmission prohibition period for prohibiting transmission at one communication rate. For example, Patent Document 1 below discloses a communication system in which a transmission prohibition period having a length corresponding to the size of data to be transmitted at one communication rate is set for transmission at one communication rate. ..

Japanese Unexamined Patent Publication No. 2012-186629

However, in the prior art as described above, for a plurality of transmissions using the same route, the transmission start time (= reference time) generally expected is different from the actual transmission start time for a certain transmission. There is a problem that the point of getting is not taken into consideration. Hereinafter, a specific description will be given with reference to FIGS. 8 and 9.

FIG. 8 is a diagram illustrating a conventional adjustment method between transmission of the first cycle data CD and transmission of the second cycle data ND using the same route. In FIG. 8, the second cycle data ND cannot be transmitted while the first cycle data CD is being transmitted, and similarly, the first cycle data CD cannot be transmitted while the second cycle data ND is being transmitted. Can not. Further, it is assumed that the transmission of the first period data CD is periodically executed in preference to the transmission of the second period data ND.

In FIG. 8, the first period data CD is buffered (that is, stored) in the first transmission queue TXQ0 together with the “transmission start time S” which is the time when the first period data CD should be transmitted, and the buffering is completed. Then, it becomes ready for transmission. Then, the first period data CD that has become transmitable is started to be transmitted to the network at the transmission start time S. That is, it is assumed that the "transmission start time S", which is the time when the first cycle data CD should be transmitted, and the actual transmission start time of the first cycle data CD coincide with each other.

The second period data ND is buffered in the second transmission queue TXQ1 and becomes ready for transmission when the buffering is completed. Then, the second cycle data ND that has become transmitable is started to be transmitted to the network in a period other than the "period during transmission of the first cycle data CD" and the "period of the transmission prohibition period B". That is, the transmission of the second cycle data ND cannot be started in the "period during transmission of the first cycle data CD" and the "period of the transmission prohibition period B". The transmission prohibition period B is set to start the transmission of the first cycle data CD at the transmission start time S, and during the transmission prohibition period B, the transmission start of the second cycle data ND is prohibited.

In FIG. 8, the first cycle data CD is periodically transmitted, and the transmission start time S of the first cycle data CD to be transmitted in the Nth cycle is “transmission start time S (n)”, and is transmitted in the N + 1 cycle. The transmission start time S of the first period data CD to be power is expressed as "transmission start time S (n + 1)". N is a "natural number greater than or equal to 0". Similarly, with respect to the transmission prohibition period B, the transmission prohibition period B set for the transmission of the first period data CD to be transmitted in the N + 1 cycle is particularly expressed as “transmission prohibition period B (n + 1)”.

When the transmission of the second cycle data ND is started between the "time retroactive from the transmission start time S (n + 1) to the time required for the transmission of the second cycle data ND" to the "transmission start time S (n + 1)", the second cycle data ND is transmitted. The time at which the transmission of the two-cycle data ND ends is later than the transmission start time S (n + 1). Then, since the transmission of the first cycle data CD cannot be started until the transmission of the second cycle data ND is completed, the transmission of the first cycle data CD cannot be started at the transmission start time S (n + 1). Therefore, the period from "the time retroactive from the transmission start time S (n + 1) to the time required for transmission of the second period data ND" to "transmission start time S (n + 1)" is set as the transmission prohibition period B. The transmission of the first period data CD can be started at the transmission start time S (n + 1).

However, the transmission start time S of the first cycle data CD can be acquired only at the same time as the first cycle data CD, that is, it cannot be grasped in advance. In FIG. 8, at the time when the buffering of the second cycle data ND is completed (the time when transmission is possible), the transmission start time S (n + 1) of the first cycle data CD to be transmitted in the N + 1 cycle is unknown, so that the second cycle When the data ND buffering is completed, the transmission prohibition period B cannot be set.

Therefore, in the conventional adjustment method illustrated in FIG. 8, instead of the transmission start time S, a time interval corresponding to the transmission cycle C of the periodically transmitted first cycle data CD is added to the transmission start time S. The "reference time T (= reference time)" which is the set time is used. The transmission cycle C is also referred to as a "control cycle".

For example, the time obtained by adding the "time interval corresponding to the transmission cycle C" to the transmission start time S (n) of the first cycle data CD in the Nth cycle is defined as the reference time T (n + 1) in the N + 1th cycle. Then, using the reference time T, the period from "the time retroactive from the reference time T to the time required for transmission of the second cycle data ND" to "reference time T" is defined as the transmission prohibition period B. In the following, it is assumed that "T (0) = S (0)".

As shown in FIG. 8, even in the conventional adjustment method, when the reference time T and the transmission start time S in each cycle always match, the transmission of the first cycle data CD is started at the transmission start time S. be able to. That is, the transmission prohibition period B (= time required for transmission of the second cycle data ND) calculated based on the data amount of the second cycle data ND is set before the reference time T (= transmission start time S). Then, the transmission of the first period data CD can be started at the transmission start time S. Specifically, in FIG. 8, the transmission prohibition period B calculated based on the data amount of the second cycle data ND is set so that the reference time T (n + 1) (= transmission start time S (n + 1)) is the end point. It is set.

However, when a discrepancy occurs between the reference time T (n + 1) and the transmission start time S (n + 1), the "time required for transmission of the second period data ND" is set as the transmission prohibition period B before the reference time T. Even if it is set, the transmission of the first cycle data CD cannot be started at the transmission start time S. Hereinafter, problems that the prior art falls into when a discrepancy occurs between the reference time T (n + 1) and the transmission start time S (n + 1) will be described with reference to FIG.

FIG. 9 shows a conventional technique in which the “time required for transmission of the second period data ND” is set before the reference time T as the transmission prohibition period B, in which the reference time T (n + 1) and the transmission start time S (n + 1) are set. It is a figure explaining the problem which occurs when the divergence occurs. FIG. 9A is a diagram illustrating a problem that occurs in the prior art when the transmission start time S (n) in the Nth cycle is delayed from the reference time T (n) in the Nth cycle. .. FIG. 9B is a diagram illustrating a problem that occurs in the prior art when the transmission start time S (n) in the Nth cycle is earlier than the reference time T (n) in the Nth cycle.

As shown in FIG. 9A, when the transmission start time S (n) in the Nth cycle is later than the reference time T (n) in the Nth cycle, “transmission” is performed at the transmission start time S (n). The reference time T (n + 1), which is the time to which the "time interval corresponding to the cycle C" is added, shows the following tendency. That is, the reference time T (n + 1) in the N + 1 cycle tends to be later than the transmission start time S (n + 1) in the N + 1 cycle. Here, in the prior art, the "time required for transmission of the second period data ND" is set as the transmission prohibition period B before the reference time T (n + 1). That is, in the prior art, a time later than the transmission start time S (n + 1) is set as a reference time T (n + 1), and before the reference time T (n + 1), "time required for transmission of the second cycle data ND". The transmission prohibition period B is set.

As described above, by setting the period from "the time retroactive from the transmission start time S (n + 1) to the time required for transmission of the second period data ND" to "the transmission start time S (n + 1)" as the transmission prohibition period B. , The transmission of the first period data CD can be started at the transmission start time S (n + 1). However, in FIG. 9A, the transmission prohibition period B, which is the “time required for transmission of the second period data ND”, is before the reference time T (n + 1), which is later than the transmission start time S (n + 1). Is set. That is, the transmission prohibition period B set by the prior art before the reference time T (n + 1) is the “transmission start time” from the “time retroactive from the transmission start time S (n + 1) to the time required to transmit the second cycle data ND”. It is later than the period until "time S (n + 1)".

As a result, the time when the second cycle data ND becomes transmitable is not included in the "period during transmission of the first cycle data CD" or the "period of the transmission prohibition period B", and is the second. Transmission of the periodic data ND is started immediately after the transmission becomes ready. In FIG. 9A, the time when the transmission of the second cycle data ND is completed is later than the transmission start time S (n + 1), and the first cycle data CD cannot be transmitted while the second cycle data ND is being transmitted. The transmission of the first period data CD cannot be started at the start time S (n + 1).

As shown in FIG. 9B, when the transmission start time S (n) in the Nth cycle is earlier than the reference time T (n) in the Nth cycle, the “transmission cycle” is set to the transmission start time S (n). The reference time T (n + 1), which is the time to which the "time interval corresponding to C" is added, shows the following tendency. That is, the reference time T (n + 1) in the N + 1 cycle tends to be earlier than the transmission start time S (n + 1) in the N + 1 cycle. Here, in the prior art, the "time required for transmission of the second period data ND" is set as the transmission prohibition period B before the reference time T (n + 1). That is, in the prior art, a time earlier than the transmission start time S (n + 1) is set as the reference time T (n + 1), and before the reference time T (n + 1), the "time required for transmission of the second cycle data ND" is used. A certain transmission prohibition period B is set.

As described above, by setting the period from "the time retroactive from the transmission start time S (n + 1) to the time required for transmission of the second period data ND" to "the transmission start time S (n + 1)" as the transmission prohibition period B. , The transmission of the first period data CD can be started at the transmission start time S (n + 1). However, in FIG. 9B, the transmission prohibition period B, which is the “time required for transmission of the second period data ND”, is set before the reference time T (n + 1) earlier than the transmission start time S (n + 1). It is set. That is, the transmission prohibition period B set by the prior art before the reference time T (n + 1) is the “transmission start time” from the “time retroactive from the transmission start time S (n + 1) to the time required to transmit the second cycle data ND”. It is earlier than the period until "time S (n + 1)".

As a result, the time when the second cycle data ND becomes transmitable is not included in the "period during transmission of the first cycle data CD" or the "period of the transmission prohibition period B", and is the second. Transmission of the periodic data ND is started immediately after the transmission becomes ready. In FIG. 9B, the time when the transmission of the second cycle data ND is completed is later than the transmission start time S (n + 1), and the first cycle data CD cannot be transmitted while the second cycle data ND is being transmitted. The transmission of the first period data CD cannot be started at the start time S (n + 1).

As described above with reference to FIGS. 8 and 9, in the prior art, the "time required for transmission of the second period data ND" calculated based on the amount of data of the second period data ND is transmitted. The prohibition period B is set before the reference time T.

However, in such a conventional technique, when the reference time T (n) and the transmission start time S (n) of the Nth cycle deviate from each other, the first cycle data CD is set at the transmission start time S (n + 1) of the N + 1th cycle. It may not be possible to start sending. That is, when the reference time (= reference time T (n)) of the first cycle data CD in the Nth cycle and the actual transmission start time (= transmission start time S (n)) deviate from each other, the prior art is N + 1. It is possible that the transmission of the first cycle data CD cannot be started at the transmission start time S (n + 1) of the cycle.

One aspect of the present disclosure has been made to solve the above-mentioned problems, and an object thereof is when the reference time of a certain cycle and the actual transmission start time deviate from each other in the data to be transmitted periodically. Another object is to realize a control device or the like capable of transmitting data at a scheduled time in the next cycle.

In order to solve the above problems, the control device according to one aspect of the present invention is a control device that outputs the first cycle data for each control cycle, and the first cycle data is converted into the first cycle data. An acquisition unit to be acquired together with the transmission start time and a time interval corresponding to the control cycle are added to the transmission start time of the first cycle data to be transmitted in the control cycle of the Nth cycle, where N is a natural number of 0 or more. It is generated using the calculation unit that calculates the reference time of the N + 1 cycle, the transmission start time of the first cycle data to be transmitted in the control cycle of the N cycle, and the difference between the reference time of the N cycle. The priority is higher than the first cycle data in the setting unit that sets the transmission prohibition period at least one before and after the reference time in the N + 1 cycle and the period other than the transmission prohibition period set by the setting unit. It is characterized by including a transmission unit that starts transmission of low second period data.

According to the above configuration, the control device takes into consideration the difference between the transmission start time of the first cycle data to be transmitted in the control cycle of the Nth cycle and the reference time of the Nth cycle, and the second cycle. The transmission prohibition period for prohibiting the start of transmission of periodic data is calculated. Then, the control device adds the time interval corresponding to the control cycle to the transmission start time of the Nth cycle, and calculates the transmission prohibition period at least one before and after the reference time of the N + 1th cycle. To set. Then, the control device starts the transmission of the second period data during a period other than the transmission prohibition period. That is, even when the transmission start time in the Nth cycle and the reference time deviate from each other, the control device sets the transmission prohibition period in consideration of the difference between the transmission start time and the reference time in the Nth cycle in the N + 1th cycle. Set at least one before and after the reference time of.

Therefore, even when the transmission start time in the Nth cycle and the reference time deviate from each other, the control device sets an appropriate transmission prohibition period in consideration of the difference between the two, and sets the transmission start time in the N + 1th cycle. It has the effect of being able to start the transmission of the first period data.

The control device according to one aspect of the present invention has a first generation unit that generates a basic period, which is a period required for transmission of the second cycle data, from the amount of data of the second cycle data, and a control cycle of the Nth cycle. Further includes a second generation unit that generates an adjustment period that is the difference between the transmission start time of the first cycle data to be transmitted to and the reference time of the Nth cycle, and the transmission set by the setting unit. The prohibition period may include the total period of the basic period and the adjustment period.

According to the above configuration, the control device takes into consideration the "difference between the transmission start time and the reference time in the control cycle of the Nth cycle" and the "data amount of the second cycle data", and the second cycle data. The transmission prohibition period in which the start of transmission is prohibited is set.

Here, since the first cycle data cannot be transmitted during the transmission of the second cycle data, it is theoretical to start the transmission of the first cycle data at the transmission start time of the N + 1 cycle. It is necessary to set the transmission prohibition period as follows. That is, it is necessary to set the period from "the time retroactive from the transmission start time of the N + 1 cycle to the time required for transmission of the second cycle data" to "the transmission start time of the N + 1 cycle" as the transmission prohibition period. be.

Then, the "time required for transmitting the second cycle data" is considered to be proportional to the data amount of the second cycle data, that is, is calculated from the data amount of the second cycle data. Therefore, the control device uses the period including the basic period generated from the data amount of the second cycle data as the transmission prohibition period.

Further, the "transmission start time in the N + 1 cycle" cannot be grasped before the acquisition of the first cycle data in the N + 1 cycle, whereas the "reference time in the N + 1 cycle" is the "N cycle". It can be calculated in advance by adding the "time interval corresponding to the control cycle" to the "transmission start time". Further, it is general that the difference between the transmission start time and the reference time in the N + 1th cycle is equal to or less than the difference between the transmission start time and the reference time in the Nth cycle. Therefore, the control device sets a period including the "adjustment period generated from the difference between the transmission start time and the reference time in the Nth cycle" with respect to the "reference time in the N + 1th cycle" as the transmission prohibition period. Set as.

Therefore, even when the transmission start time and the reference time in the Nth cycle deviate from each other, the control device appropriately prohibits the transmission in consideration of the difference between the two and the data amount of the second cycle data. It has the effect of being able to set the period.

In the control device according to one aspect of the present invention, when the transmission start time of the first cycle data to be transmitted in the control cycle of the Nth cycle is later than the reference time of the Nth cycle, the setting unit performs the N + 1 cycle. A period including the total period of the basic period and the adjustment period may be set as the transmission prohibition period so that the reference time of the eye is the end point.

According to the above configuration, when the transmission start time in the Nth cycle is later than the reference time in the Nth cycle, the control device has the basic period so that the reference time in the N + 1th cycle becomes the end point. A period including the total period of the adjustment period and the adjustment period is set as the transmission prohibition period.

Here, when the transmission start time in the Nth cycle is later than the reference time in the Nth cycle, the N + 1th cycle is calculated by adding a time interval corresponding to the control cycle to the transmission start time in the Nth cycle. The reference time of the above is generally later than the transmission start time of the N + 1 cycle.

Therefore, only the period from "the time retroactive to the basic period corresponding to the time required for transmission of the second cycle data from the reference time in the N + 1 cycle" to "the reference time in the N + 1 cycle" is described. Setting it as a transmission prohibition period may not be sufficient. In other words, the desirable transmission prohibition period is considered to be longer than the period from "the time retroactive from the reference time in the N + 1 cycle to the reference time in the N + 1 cycle" to "the reference time in the N + 1 cycle".

Therefore, the control device further sets the transmission prohibition period in the N + 1 cycle in consideration of the difference between the transmission start time and the reference time in the Nth cycle. That is, in addition to setting the basic period as the transmission prohibition period, the control device sets the "adjustment period, which is the difference period between the transmission start time and the reference time in the Nth cycle", in the transmission. Set as a prohibited period. Specifically, the control device is from "a time retroactive from the reference time in the N + 1 cycle to a period including the total period of the basic period and the adjustment period" to "the reference time in the N + 1 cycle". Is set as the transmission prohibition period.

Therefore, even when the transmission start time in the Nth cycle is later than the reference time, the control device considers the difference between the two and the data amount of the second cycle data, and has an appropriate transmission prohibition period. It has the effect of being able to set.

In the control device according to one aspect of the present invention, when the transmission start time of the first cycle data to be transmitted in the control cycle of the Nth cycle is earlier than the reference time of the Nth cycle, the setting unit performs the N + 1 cycle. The period including the basic period is set as the transmission prohibition period so that the reference time of the eye is the end point, and the transmission prohibition period is the period including the adjustment period so that the reference time of the N + 1th cycle is the start point. It may be set as.

According to the above configuration, when the transmission start time in the Nth cycle is earlier than the reference time in the Nth cycle, the control device includes the basic period so that the reference time in the N + 1th cycle becomes the end point. The period is set as the transmission prohibition period. Further, the control device sets a period including the adjustment period as the transmission prohibition period so that the reference time in the N + 1 cycle becomes the starting point.

Here, when the transmission start time in the Nth cycle is earlier than the reference time in the Nth cycle, the N + 1th cycle is calculated by adding a time interval corresponding to the control cycle to the transmission start time in the Nth cycle. The reference time of the above is generally earlier than the transmission start time of the N + 1 cycle.

Therefore, only the period from "the time retroactive to the basic period corresponding to the time required for transmission of the second cycle data from the reference time in the N + 1 cycle" to "the reference time in the N + 1 cycle" is described. Setting it as a transmission prohibition period may not be sufficient. In other words, the desirable transmission prohibition period is considered to be longer than the period from "the time retroactive from the reference time in the N + 1 cycle to the reference time in the N + 1 cycle" to "the reference time in the N + 1 cycle".

Therefore, the control device further sets the transmission prohibition period in the N + 1 cycle in consideration of the difference between the transmission start time and the reference time in the Nth cycle. That is, in addition to setting the basic period as the transmission prohibition period, the control device sets the "adjustment period, which is the difference period between the transmission start time and the reference time in the Nth cycle", in the transmission. Set as a prohibited period. Specifically, the control device sets a period from "a time retroactive to the basic period from the reference time in the N + 1 cycle" to "the reference time in the N + 1 cycle" as the transmission prohibition period. .. Further, the control device sets a period from "the reference time in the N + 1 cycle" to "the time advanced from the reference time in the N + 1 cycle to the time including the adjustment period" as the transmission prohibition period. do.

Therefore, even when the transmission start time in the Nth cycle is earlier than the reference time, the control device takes into consideration the difference between the two and the amount of data in the second cycle data, and has an appropriate transmission prohibition period. It has the effect of being able to set.

In the control device according to one aspect of the present invention, if the transmission unit does not continuously transmit the second cycle data over a predetermined number of times of the control cycle, the control device is forcibly described even during the transmission prohibition period. The transmission unit may further include an instruction unit for starting the transmission of the second period data.

According to the above configuration, if the control device does not continuously transmit the second cycle data over a predetermined number of times of the control cycle, the control device is forced to transmit the second cycle data even during the transmission prohibition period. Start sending. Therefore, the control device has the effect of being able to transmit the second cycle data that has not been continuously transmitted over the predetermined number of control cycles.

In the control device according to one aspect of the present invention, if the transmission unit does not transmit the second cycle data continuously over the control cycle of a predetermined number of times, the transmission unit continues over the control cycle of the predetermined number of times. Further, a notification unit may be further provided to notify the outside that the second period data is not transmitted.

According to the above configuration, if the control device does not continuously transmit the second cycle data over the predetermined number of control cycles, the control device continuously transmits the second cycle data over the predetermined number of control cycles. Notify the outside that you have not done so. Therefore, when a situation occurs in which the second cycle data is not continuously transmitted over the predetermined number of times of the control cycle, the control device notifies the outside that such a situation has occurred. It has the effect of being able to.

In order to solve the above problems, the control method according to one aspect of the present invention is a control method for a control device that outputs first cycle data for each control cycle, and the first cycle data is used for the first cycle data. A time interval corresponding to the control cycle is set at the acquisition step to be acquired together with the transmission start time of the periodic data and the transmission start time of the first cycle data to be transmitted in the control cycle of the Nth cycle, where N is a natural number of 0 or more. Is added to calculate the reference time of the N + 1 cycle, and the difference between the transmission start time of the first cycle data to be transmitted in the control cycle of the N cycle and the reference time of the N cycle is used. The first cycle data is set in at least one of the setting steps before and after the reference time in the N + 1 cycle, and in a period other than the transmission prohibition period set in the setting step. It is characterized by including a transmission step of initiating transmission of second period data having a lower priority.

According to the method, the control method takes into consideration the difference between the transmission start time of the first cycle data to be transmitted in the control cycle of the Nth cycle and the reference time of the Nth cycle, and the second control method. The transmission prohibition period for prohibiting the start of transmission of periodic data is calculated. Then, in the control method, the transmission prohibition period is set at least one before and after the reference time in the N + 1 cycle, which is calculated by adding a time interval corresponding to the control cycle to the transmission start time in the N cycle. To set. Then, the control method starts the transmission of the second period data during a period other than the transmission prohibition period. That is, in the control method, even when the transmission start time in the Nth cycle and the reference time deviate from each other, the transmission prohibition period in consideration of the difference between the transmission start time and the reference time in the Nth cycle is set to the N + 1th cycle. Set at least one before and after the reference time of.

Therefore, in the control method, even when the transmission start time in the Nth cycle and the reference time deviate from each other, an appropriate transmission prohibition period is set in consideration of the difference between the two, and the transmission start time in the N + 1th cycle is set. It has the effect of being able to start the transmission of the first period data.

According to one aspect of the present disclosure, regarding data to be transmitted periodically, even if the reference time of a certain cycle and the actual transmission start time deviate from each other, the data is transmitted at the scheduled time of the next cycle. It has the effect of being able to.

It is a figure which shows the structural example of the CPU unit of PLC which concerns on one Embodiment of this invention. It is a figure which shows the outline of the control system including PLC which concerns on one Embodiment of this invention. It is a flow diagram which shows the whole outline of the process which a CPU unit (particularly FPGA) of FIG. 1 executes. It is a flow diagram explaining the details of the transmission prohibition period calculation process of FIG. It is a flow diagram explaining the details of the transmission prohibition period setting process of FIG. It is a figure which shows an example of the process which the CPU unit (particularly FPGA) of FIG. 1 executes when the transmission start time is later than the reference time in the Nth cycle. It is a figure which shows an example of the process which the CPU unit (particularly FPGA) of FIG. 1 executes when the transmission start time is earlier than the reference time in the Nth cycle. It is a figure explaining the conventional adjustment method about two transmissions using the same route. It is a figure explaining the problem which occurs when the reference time and the transmission start time deviate from each other about the prior art.

[Embodiment 1]
Hereinafter, an embodiment according to one aspect of the present invention (hereinafter, also referred to as “the present embodiment”) will be described with reference to the drawings, and specifically, the first embodiment of the present invention will be described from FIGS. 1 to 1. It will be described in detail based on 9. The same or corresponding parts in the drawings are designated by the same reference numerals and the description thereof will not be repeated. In the present embodiment, a PLC (Programmable Logic Controller) 10 that controls a controlled object such as a machine and equipment, and in particular, a CPU unit 100 of the PLC 10 will be described as a typical example of a control device. .. Note that "CPU" is an abbreviation for "Central Processing Unit". Further, in the following description, "N" represents "a natural number of 0 or more".

In order to facilitate the understanding of the PLC 10, the outline of the prior art will be described first with reference to FIGS. 8 and 9, and then the outline of the PLC 10 will be described.

§1. Application example (Outline of prior art and issues)
In FIG. 8, the transmission of the first cycle data CD and the transmission of the second cycle data ND use the same route, and during the transmission of the first cycle data CD, the second cycle data ND cannot be transmitted, and the second cycle data ND cannot be transmitted. While the periodic data ND is being transmitted, the first periodic data CD cannot be transmitted. The first cycle data CD is buffered in the first transmission queue TXQ0 together with the "transmission start time S" which is the time when the first cycle data CD should be transmitted, and when the buffering is completed, the first cycle data CD is in a transmittable state. Similarly, the second period data ND is buffered in the second transmission queue TXQ1 and becomes ready for transmission when the buffering is completed. The first cycle data CD is periodically transmitted, the transmission start time S of the first cycle data CD to be transmitted in the Nth cycle is "transmission start time S (n)", and the first cycle to be transmitted in the N + 1 cycle. The transmission start time S of the data CD is expressed as "transmission start time S (n + 1)".

In the prior art, since the transmission of the first cycle data CD in the transmittable state is started at the transmission start time S, the "time required for the transmission of the second cycle data ND" is based on the data amount of the second cycle data ND. The "time required for transmission of the second period data ND" calculated in the above is used.

That is, in the prior art, first, the "time interval corresponding to the transmission cycle C" is added to the "transmission start time S (n) of the first cycle data CD in the Nth cycle", and the "reference time T in the N + 1th cycle T" is added. (N + 1) ”is calculated. Then, in the prior art, the "time required for the transmission of the second cycle data ND" is set to the transmission prohibition period for prohibiting the start of the transmission of the second cycle data ND so that the reference time T (n + 1) in the N + 1 cycle is the end point. It is set as B (“transmission prohibition period B (n + 1)” in FIG. 8).

However, as shown in FIG. 9, the conventional technique of using the "time required for transmission of the second cycle data ND" calculated based on the amount of data of the second cycle data ND as the transmission prohibition period B is the reference time T. It is not possible to deal with the case where (n) and the transmission start time S (n) in the Nth cycle deviate from each other. That is, when the reference time (= reference time T (n)) of the first cycle data CD in the Nth cycle and the actual transmission start time (= transmission start time S (n)) deviate from each other, the prior art is N + 1. It is possible that the transmission of the first cycle data CD cannot be started at the transmission start time S (n + 1) of the cycle.

As described with reference to FIGS. 8 and 9, the conventional technique of setting the transmission prohibition period B only from the amount of data (the size of the data size) of the second period data ND has the following problems. That is, if the transmission prohibition period B is set only from the data amount of the second cycle data ND, the reference time (= reference time T) calculated from the periodic transmission cycle and the actual transmission time of the periodic transmission (= transmission start time S) are set. If does not match, you may not be able to keep the regular transmission. That is, if the error between the N + 1th transmission start time S (n + 1) and the N + 1th reference time T (n + 1) is large, the prior art may not be able to set an appropriate transmission prohibition period B. As a result, for example, the transmission of TXQ1 may be started before the transmission of TXQ0, and the transmission of the first period data CD may not be started at the transmission start time S (n + 1).

Therefore, the PLC 10 sets the adjustment period Ba (margin time) in addition to the "time required for transmission of the second period data ND (= basic period Bb)" calculated based on the amount of data of the second period data ND. Set as the transmission prohibition period B. In particular, the PLC 10 dynamically changes the adjustment period Ba (in the N + 1 cycle) according to the state of the previous transmission (that is, the transmission state of the first cycle data CD in the Nth cycle), and optimizes the adjustment period Ba. Perform the conversion. Hereinafter, the outline of the control system 1 including the PLC 10 will be described with reference to FIG.

(Outline of PLC according to this embodiment)
FIG. 2 is a diagram showing an overall outline of the control system 1. In the control system 1 illustrated in FIG. 1, one or more PLCs 10 and a device whose operation is controlled by the PLC10 are connected to a control system network such as a field network 20. Servo drivers 33 and 34 are connected to the PLC 10 of FIG. 2 via a network such as the field network 20 and the PLC system bus 400, and each of the servo drivers 33 and 34 is further connected to each of the servo motors 41 and 42. Has been done.

The PLC 10 is a control device that controls an input device and an output device in a production facility. For example, the PLC 10 transmits a first cycle data CD and a second cycle data ND to a network such as the field network 20 and the PLC system bus 400, and particularly for the transmission of the first cycle data CD and the second cycle data ND. Execute the following processing. That is, in order to avoid the situation that "the transmission of the first cycle data CD cannot be started at the transmission start time S due to the transmission of the second cycle data ND", the PLC 10 is prohibited from transmitting the second cycle data ND. Set the transmission prohibition period B. In the following, it is assumed that the PLC 10 transmits the first cycle data CD periodically (specifically, every control cycle (specifically, transmission cycle C)). Hereinafter, the transmission / reception of the first cycle data CD and the second cycle data ND controlled by the PLC 10 will be described in detail.

(Transmission and reception of 1st period data CD)
First, the PLC 10 and the equipment communicate cyclically (that is, periodically) via the field network 20 in order to execute high-speed and high-precision control over the production equipment, and IN data and OUT data are used. Send and receive (hereinafter referred to as "IO data"). The first period data CD is, for example, such "IO data for executing high-speed and high-precision control for production equipment", and "data for executing high-speed and high-precision control for production equipment" is "data". Also called "control data".

The PLC 10 executes high-speed and high-precision control for a controlled object by executing a user program generated by compiling a ladder program (source program) or the like described by ladder logic (ladder language). Here, the "user program" is created according to the user's controlled object (for example, the target line and process), that is, according to the controlled object line (process) controlled by the control system 1. It is a program designed arbitrarily. The user program in the object program format is stored in the non-volatile memory 105 or the like of the PLC 10. The user program is executed by the microprocessor 103 of the CPU unit 100, and the execution result is transmitted to the control target of the PLC 10 as control data, that is, as first cycle data CD.

Specifically, the user program for high-speed and high-precision control of the controlled object is repeatedly executed by the microprocessor 103 at a high-speed cycle, and the PLC 10 outputs the first cycle data CD, which is the execution result, at a fixed cycle. Send to the controlled object. The PLC 10 (particularly, the CPU unit 100) transmits the first cycle data CD to the functional units such as IO units 301 to 303 and the special unit 304 and the slave devices such as the servo drivers 33 and 34 and the remote IO terminal 35 in a fixed cycle. Send with. Here, in order to control the production equipment at high speed and with high accuracy, it is necessary to increase the command frequency from the PLC 10 to each control device, and the transmission of the first period data CD to the slave device (field device) by the PLC 10 is performed. Is required to communicate in the order of μs.

(Transmission and reception of second period data ND)
Second, the PLC 10 (particularly, the CPU unit 100) executes the following processing in addition to high-speed and high-precision control of the production equipment. That is, the PLC 10 has accumulated and accumulated, for example, (1) processing related to connection with an external database, (2) processing related to connection with an external display device, and (3) information acquired from a control target. Executes processing such as sending information to an external server. Specifically, the PLC 10 transmits and receives (collects) data other than the first period data CD (control data), for example, a functional unit, a slave device, and various external devices (for example, an external device). The second period data ND is transmitted to and received from the information system server).

The second period data ND is, for example, information system data showing statistical information of the attenuation value of the sensor received signal used for failure diagnosis of the control system 1. The second cycle data ND has a lower priority than the first cycle data CD, and the details will be described later, but the transmission of the first cycle data CD at the transmission start time may be hindered by the transmission of the second cycle data ND. The start of transmission of the second period data ND is controlled (prohibited) so as not to occur. The second period data ND is repeatedly transmitted aperiodically or at a time interval (cycle) equal to or longer than the "transmission cycle C (= control cycle) of the first cycle data CD transmitted periodically". As described above, in the PLC10, the punctuality of the order of "μs (1 / 1,000,000 second)" is required for the first cycle data CD transmitted at a fixed cycle. On the other hand, the punctuality required for the transmission of the second period data ND is, for example, on the order of ms (thousandths of a second).

(Overview of the equipment that makes up the control system)
The PLC 10 is a control device that controls control targets such as machines and equipment in the control system 1, and is a master device that manages data transmission via the field network 20 in the control system 1. The PLC 10 executes a control program, which is also called a user program, for example, and controls the operation of the entire control system 1 in an integrated manner. The PLC 10 includes a CPU unit 100 that executes main arithmetic processing, a power supply unit 200, one or more IO (Input / Output) units (IO units 301 to 303 in the example of FIG. 2), and a special unit 304. including. IO units 301 to 303 and special units 304 may also be referred to as functional units. The CPU unit 100, each of the IO units 301 to 303, and the special unit 304 are configured so that data can be exchanged with each other via the PLC system bus 400.

The CPU unit 100 executes various processes related to the state of the controlled object, for example, "transmission of output data, reception of input data, and execution of a control program that generates output data using the input data." "Controlling the controlled object by repeating" is executed. Details of the CPU unit 100 will be described later with reference to FIG.

The power supply unit 200 supplies power to the CPU unit 100, IO units 301 to 303, and the special unit 304 with an appropriate voltage.

Each of the IO units 301 to 303 is a unit related to general input / output processing, and controls input / output of data such as on / off (that is, binarized data). Specifically, in each of the IO units 301 to 303, a state in which the device 31 which is an input device such as a sensor detects some object (on), and a state in which no object is detected (in the state). Gather information about which of the off). Further, each of the IO units 301 to 303 has either a command (on) for activating or a command (off) for inactivating the device 32, which is an output device such as a relay or an actuator. Is output.

The special unit 304 has functions that the IO units 301 to 303 do not support, such as input / output of data (for example, analog data) different from the data processed by the IO units 301 to 303, temperature control, and communication by a specific communication method. ..

The field network 20 transmits various data exchanged between the CPU unit 100 and the field equipment (servo driver 33, servo driver 34, remote IO terminal 35, etc.). As the field network 20, various types of Industrial Ethernet (registered trademark) can be typically used. As industrial Ethernet, for example, EtherCAT (registered trademark), Profile IRT, MECHATROLINK (registered trademark) -III, Powerlink, SERCOS (registered trademark) -III, CIP Motion and the like are known. As the field network 20, a field network other than Industrial Ethernet may be used. For example, if motion control is not performed, DeviceNet, CompoNet / IP (registered trademark), or the like may be used.

In the PLC 10, the CPU unit 100 is provided with the functions of the IO units 301 to 303 and the functions of the servo drivers 33 and 34, so that the CPU unit 100 directly controls the range covered by such built-in functions. You may control it.

Each of the servo drivers 33 and 34 is connected to the CPU unit 100 via the field network 20 and drives each of the servomotors 41 and 42 according to the command value from the CPU unit 100. Note that FIG. 2 shows an example of a system in which each of the servo motors 41 and 42 and each of the servo drivers 33 and 34 are combined, but other configurations, for example, a system in which a pulse motor and a pulse motor driver are combined are shown. Can also be adopted.

The remote IO terminal 35 basically performs processing related to general input / output processing in the same manner as the IO units 301 to 303. More specifically, the remote IO terminal 35 includes a communication coupler 36 for performing processing related to data transmission in the field network 20 and one or more IO units (IO units 37 and 38 in the example of FIG. 2). And include. The communication coupler 36 and each of the IO units 37 and 38 are configured so that data can be exchanged with each other via the remote IO terminal bus 39.

The analysis device 50 is connected to the PLC 10 by an arbitrary communication cable 40, and may be communication-connected by, for example, Ether IP (registered trademark). If the PLC 10 does not continuously transmit the second cycle data ND over a predetermined number of control cycles after the second cycle data ND becomes transmitable, the PLC 10 "consecutively second cycle over a predetermined number of control cycles. Notify the analysis device 50 that "data ND has not been transmitted". When the analysis device 50 is notified by the PLC 10 that "the second cycle data ND is not continuously transmitted over a predetermined number of control cycles", the analysis device 50 displays to that effect to the user. The analysis device 50 is composed of a normal PC (Personal Computer) and includes input / output devices such as a touch panel and a display.

(Overview of CPU unit)
Up to now, the overall outline of the control system 1 including the PLC 10 has been described with reference to FIG. 2, but next, the outline of the CPU unit 100 in the PLC 10, particularly the FPGA 101 included in the CPU unit 100 will be described.

The PLC 10 is a control device that outputs a first cycle data CD for each control cycle (specifically, transmission cycle C), and is an acquisition unit 110, a calculation unit 130, a setting unit 160, and a second transmission unit. 170 (2) (transmitter) and. The acquisition unit 110 acquires the first cycle data CD together with the transmission start time S of the first cycle data CD. The calculation unit 130 corresponds to the transmission cycle C at the transmission start time S (n) of the first cycle data CD to be transmitted in the control cycle (= transmission cycle C) of the Nth cycle, where N is a natural number of 0 or more. The reference time T (n + 1) in the N + 1 cycle is calculated by adding a time interval. The setting unit 160 is a transmission generated by using the difference between the transmission start time S (n) of the first cycle data CD to be transmitted in the control cycle of the Nth cycle and the reference time T (n) of the Nth cycle. The prohibition period B (specifically, the transmission prohibition period B (n + 1)) is set at least one before and after the reference time T (n + 1) in the N + 1 cycle. The second transmission unit 170 (2) starts the transmission of the second cycle data ND, which has a lower priority than the first cycle data CD, during the period other than the transmission prohibition period B set by the setting unit 160.

According to the above configuration, the PLC 10 considers the difference between the transmission start time S (n) of the first cycle data CD to be transmitted in the control cycle of the Nth cycle and the reference time T (n) of the Nth cycle. Then, the transmission prohibition period B for prohibiting the start of transmission of the second period data ND is calculated. Then, the PLC 10 is calculated by adding a time interval corresponding to the transmission cycle C to the transmission start time S (n) in the Nth cycle, at least one of the front and the back of the reference time T (n + 1) in the N + 1th cycle. , Set the transmission prohibition period B (n + 1). Then, the PLC 10 starts the transmission of the second period data ND during the period other than the transmission prohibition period B (n + 1). That is, the PLC 10 has the transmission start time S (n) and the reference time T (n) in the Nth cycle even when the transmission start time S (n) in the Nth cycle and the reference time T (n) deviate from each other. The transmission prohibition period B (n + 1) in consideration of the difference between the two is set at least one before and after the reference time T (n + 1) in the N + 1 cycle.

Therefore, even when the transmission start time S (n) and the reference time T (n) in the Nth cycle deviate from each other, the PLC 10 sets an appropriate transmission prohibition period B (n + 1) in consideration of the difference between the two. It is effective that the transmission of the first cycle data CD can be started at the transmission start time S (n + 1) in the N + 1th cycle.

The PLC 10 further includes a first generation unit 140 and a second generation unit 150. The first generation unit 140 generates a basic period Bb, which is a period required for transmission of the second period data ND, from the amount of data of the second period data ND. The second generation unit 150 "is the difference (= difference period) between the transmission start time S (n) of the first cycle data CD to be transmitted in the control cycle of the Nth cycle and the reference time T (n) of the Nth cycle. The adjustment period Ba, which is "V (n))", is generated. Then, in the PLC 10, the transmission prohibition period B set by the setting unit 160 includes the total period of the basic period Bb and the adjustment period Ba.

According to the above configuration, the PLC 10 considers "the difference between the transmission start time S (n) and the reference time T (n) in the control cycle of the Nth cycle" and "the amount of data in the second cycle data ND". Therefore, the transmission prohibition period B in which the start of transmission of the second period data ND is prohibited is set.

Here, since the first cycle data CD cannot be transmitted during the transmission of the second cycle data ND, the transmission of the first cycle data CD can be started at the transmission start time S (n + 1) of the N + 1th cycle. , Theoretically, it is necessary to set the transmission prohibition period B (n + 1) as follows. That is, from "the time retroactive from the transmission start time S (n + 1) in the N + 1 cycle to the time required for transmission of the second cycle data ND (= basic period Bb)" to "the transmission start time S (n + 1) in the N + 1 cycle". It is necessary to set the period up to "the transmission prohibition period B".

Then, the "time required for transmission of the second cycle data ND (= basic period Bb)" is considered to be proportional to the data amount of the second cycle data ND, that is, calculated from the data amount of the second cycle data ND. .. Therefore, the PLC 10 uses the period including the basic period Bb generated from the data amount of the second period data ND as the transmission prohibition period B.

Further, the "transmission start time S (n + 1) in the N + 1 cycle" cannot be grasped before the acquisition of the first cycle data CD in the N + 1 cycle, whereas the "reference time T (n + 1) in the N + 1 cycle" is. , N + 1 can be grasped before the acquisition of the first cycle data CD of the cycle. That is, the PLC 10 adds a "time interval corresponding to the control cycle (= transmission cycle C)" to the "Nth cycle transmission start time S (n)" and "N + 1th cycle reference time T (n + 1)). Is calculated in advance before the acquisition of the first cycle data CD in the N + 1th cycle.

Further, the "difference between the transmission start time S (n + 1) and the reference time T (n + 1) in the N + 1th cycle" is "the difference between the transmission start time S (n) and the reference time T (n) in the Nth cycle". It is generally less than or equal to the difference.

Therefore, the PLC 10 sets the "adjustment period Ba generated from the difference between the transmission start time S (n) and the reference time T (n) in the Nth cycle" with respect to the "reference time T (n + 1) in the N + 1th cycle". The included period is set as the transmission prohibition period B.

Therefore, the PLC 10 is appropriate in consideration of the difference between the transmission start time S (n) and the reference time T (n) in the Nth cycle and the data amount of the second cycle data ND. It is effective that the transmission prohibition period B (n + 1) can be set.

In the PLC10, when the transmission start time S (n) of the first cycle data CD to be transmitted in the control cycle of the Nth cycle is later than the reference time T (n) of the Nth cycle, the setting unit 160 sets the following. The transmission prohibition period B (n + 1) is set so as to be. That is, the setting unit 160 sets the transmission prohibition period B for a period including the total period of the basic period Bb (n + 1) and the adjustment period Ba (n + 1) so that the reference time T (n + 1) in the N + 1 cycle becomes the end point. Set as (n + 1).

According to the above configuration, when the transmission start time S (n) in the Nth cycle is later than the reference time T (n) in the Nth cycle, the PLC10 ends at the reference time T (n + 1) in the N + 1th cycle. Therefore, the period including the total period of the basic period Bb (n + 1) and the adjustment period Ba (n + 1) is set as the transmission prohibition period B (n + 1).

Here, when the transmission start time S (n) of the Nth cycle is later than the reference time T (n) of the Nth cycle, the time interval corresponding to the transmission cycle C at the transmission start time S (n) of the Nth cycle. The reference time T (n + 1) in the N + 1 cycle calculated by adding the above is generally later than the transmission start time S (n + 1) in the N + 1 cycle.

Therefore, from "the time retroactive from the reference time T (n + 1) in the N + 1 cycle to the basic period Bb (n + 1) corresponding to the time required for transmitting the second cycle data ND" to "the reference time T (n + 1) in the N + 1 cycle". It may not be sufficient to set only the period up to ")" as the transmission prohibition period B (n + 1). In other words, the desirable transmission prohibition period B (n + 1) is from "the time retroactive from the reference time T (n + 1) in the N + 1 cycle to the base time Bb (n + 1) in the N + 1 cycle" to "the reference time T (n + 1) in the N + 1 cycle". It is considered to be longer than the period of.

Therefore, the PLC 10 further sets the transmission prohibition period B (n + 1) in the N + 1th cycle in consideration of the difference between the transmission start time S (n) and the reference time T (n) in the Nth cycle. That is, in addition to setting the basic period Bb (n + 1) as the transmission prohibition period B (n + 1), the PLC 10 has a difference period V which is a difference period between the transmission start time S (n) and the reference time T (n). (N) is set as the transmission prohibition period B (n + 1). Specifically, the PLC 10 has an "N + 1 cycle" from "a time retroactive from the reference time T (n + 1) in the N + 1 cycle to a period including the total period of the basic period Bb (n + 1) and the adjustment period Ba (n + 1)". The period up to the reference time T (n + 1) of the eye is set as the transmission prohibition period B (n + 1).

Therefore, the PLC 10 is appropriate in consideration of the difference between the two and the data amount of the second cycle data ND even when the transmission start time S (n) is later than the reference time T (n) in the Nth cycle. It has the effect that the transmission prohibition period B (n + 1) can be set.

In the PLC10, when the transmission start time S (n) of the first cycle data CD to be transmitted in the control cycle of the Nth cycle is earlier than the reference time T (n) of the Nth cycle, the setting unit 160 sets the following. The transmission prohibition period B (n + 1) is set so as to be. That is, the setting unit 160 sets the period including the basic period Bb (n + 1) as the transmission prohibition period B (n + 1) so that the reference time T (n + 1) in the N + 1 cycle becomes the end point. Further, the setting unit 160 sets a period including the adjustment period Ba (n + 1) as the transmission prohibition period B (n + 1) so that the reference time T (n + 1) in the N + 1 cycle becomes the starting point.

According to the above configuration, when the transmission start time S (n) in the Nth cycle is earlier than the reference time T (n) in the Nth cycle, the PLC10 ends at the reference time T (n + 1) in the N + 1th cycle. Therefore, the period including the basic period Bb (n + 1) is set as the transmission prohibition period B (n + 1). Further, the PLC 10 sets a period including the adjustment period Ba (n + 1) as the transmission prohibition period B (n + 1) so that the reference time T (n + 1) in the N + 1 cycle becomes the starting point.

Here, when the transmission start time S (n) of the Nth cycle is earlier than the reference time T (n) of the Nth cycle, the time interval corresponding to the transmission cycle C at the transmission start time S (n) of the Nth cycle. The reference time T (n + 1) in the N + 1 cycle calculated by adding the above is generally earlier than the transmission start time S (n + 1) in the N + 1 cycle.

Therefore, from "the time retroactive from the reference time T (n + 1) in the N + 1 cycle to the basic period Bb (n + 1) corresponding to the time required for transmitting the second cycle data ND" to "the reference time T (n + 1) in the N + 1 cycle". It may not be sufficient to set only the period up to ")" as the transmission prohibition period B (n + 1). In other words, the desirable transmission prohibition period B (n + 1) is from "the time retroactive from the reference time T (n + 1) in the N + 1 cycle to the base time Bb (n + 1) in the N + 1 cycle" to "the reference time T (n + 1) in the N + 1 cycle". It is considered to be longer than the period of.

Therefore, the PLC 10 further sets the transmission prohibition period B (n + 1) in the N + 1th cycle in consideration of the difference between the transmission start time S (n) and the reference time T (n) in the Nth cycle. That is, in addition to setting the basic period Bb (n + 1) as the transmission prohibition period B (n + 1), the PLC 10 has a difference period V which is a difference period between the transmission start time S (n) and the reference time T (n). (N) is set as the transmission prohibition period B (n + 1). Specifically, the PLC 10 sets the period from "the time retroactive from the reference time T (n + 1) in the N + 1 cycle to the basic period Bb (n + 1)" to "the reference time T (n + 1) in the N + 1 cycle". It is set as the transmission prohibition period B (n + 1). Further, the PLC 10 sets the period from "the reference time T (n + 1) in the N + 1 cycle" to "the time advanced from the reference time T (n + 1) in the N + 1 cycle to the time including the adjustment period Ba (n + 1)". , Set as the transmission prohibition period B (n + 1).

Therefore, the PLC 10 is appropriate in consideration of the difference between the two and the data amount of the second cycle data ND even when the transmission start time S (n) is earlier than the reference time T (n) in the Nth cycle. It has the effect that the transmission prohibition period B (n + 1) can be set.

The PLC 10 further includes an indicator 180. The instruction unit 180 states that "the second transmission unit 170 (2) does not continuously transmit the second cycle data ND over a predetermined number of control cycles (= transmission cycle C)" in the transmission prohibition period B. Also forcibly causes the second transmission unit 170 (2) to start the transmission of the second period data ND.

According to the above configuration, the PLC 10 forcibly starts the transmission of the second cycle data ND even in the transmission prohibition period B unless the second cycle data ND is continuously transmitted over a predetermined number of control cycles. do. Therefore, the PLC 10 has the effect of being able to transmit the second period data ND that has not been continuously transmitted over a predetermined number of control cycles.

The PLC 10 further includes a notification unit 190. The notification unit 190 states that "the second transmission unit 170 (2) does not continuously transmit the second cycle data ND over a predetermined number of control cycles" and "the second transmission unit 170 (2) has a predetermined number of times." Notify the outside that the second cycle data ND is not continuously transmitted over the control cycle.

According to the above configuration, the PLC 10 "does not continuously transmit the second cycle data ND over a predetermined number of control cycles" unless the second cycle data ND is continuously transmitted over a predetermined number of control cycles. Notify the outside. Therefore, when the situation that "the second cycle data ND is not continuously transmitted over a predetermined number of control cycles" occurs, the PLC 10 may notify the outside that such a situation has occurred. It has the effect of being able to do it.

With respect to the PLC 10 outlined above, a hardware configuration example of the PLC 10 (particularly, the CPU unit 100 of the PLC 10) and a functional block (particularly provided in the FPGA 101) will be described with reference to FIG.

§2. Configuration example (hardware configuration of CPU unit)
FIG. 1 is a diagram showing a configuration example of the CPU unit 100 of the PLC 10. As illustrated in FIG. 1, the CPU unit 100 includes an FPGA 101, a chipset 102, a microprocessor 103, a main memory 104, and a non-volatile memory 105 as hardware configurations. The CPU unit 100 may further include a USB connector (not shown). The chipset 102 and other components are connected to each other via various buses (internal buses). The microprocessor 103 and the chipset 102 may be integrally formed.

The microprocessor 103 and the chipset 102 are typically configured according to a general purpose computer architecture. That is, the microprocessor 103 interprets and executes the instruction code sequentially supplied from the chipset 102 according to the internal clock. The chipset 102 exchanges internal data with various connected components and generates instruction codes necessary for the microprocessor 103. Further, the chipset 102 has a function of caching data and the like obtained as a result of executing arithmetic processing in the microprocessor 103.

The CPU unit 100 includes a main memory 104 and a non-volatile memory 105 as storage means. The main memory 104 is a volatile storage area (RAM) and holds various programs to be executed by the microprocessor 103 after the power is turned on to the CPU unit 100. The main memory 104 is also used as a working memory when executing various programs by the microprocessor 103. As such a main memory 104, for example, a DRAM (Dynamic Random Access Memory), a SRAM (Static Random Access Memory), or the like can be used.

On the other hand, the non-volatile memory 105 non-volatilely holds data such as various programs and parameters. These data are copied to the main memory 104 for access by the microprocessor 103, if necessary. As such a non-volatile memory 105, a semiconductor memory such as a flash memory can be used. Alternatively, a magnetic recording medium such as a hard disk drive, an optical recording medium such as a DVD-RAM (Digital Versatile Disk Random Access Memory), or the like can be used.

The FPGA 101 is a programmable logic circuit whose circuit configuration can be set by a user after manufacturing, and executes various processes including communication processes such as transmission of output data and reception of input data. As communication processing, the FPGA 101 executes transmission of output data to a unit other than the CPU unit 100 and a device other than the PLC10, and reception of input data from a unit other than the CPU unit 100 and a device other than the PLC10. Further, the FPGA 101 executes data transmission / reception with / from the main memory 104 as a communication process. However, the processing executed by the FPGA 101 is not limited to the communication processing.

In the present embodiment, the data output from the CPU unit 100 to a unit other than the CPU unit 100 and the data output from the PLC 10 to a device other than the PLC 10 are also referred to as "output data". Further, the data input to the CPU unit 100 from a unit other than the CPU unit 100 and the data input to the PLC 10 from a device other than the PLC 10 are also referred to as "input data".

(Overview of transmission preparation processing for the 1st cycle data CD and the 2nd cycle data ND)
The microprocessor 103 transmits the first cycle data CD (for example, control data) and the second cycle data ND (for example, data other than the control data) to be transmitted to the outside of the CPU unit 100 via the chip set 102, for example. Set in main memory 104 (in other words, store data). Then, the microprocessor 103 requests the FPGA 101 to transmit the data set in the main memory 104 via the chipset 102. For example, the microprocessor 103 may be composed of a plurality of cores, and each core may store the data assigned to each core in the main memory 104 via the chipset 102. For example, the first core stores the first cycle data CD in the main memory 104, requests the FPGA 101 to transmit the first cycle data CD, and the second core stores the second cycle data ND in the main memory 104. The FPGA 101 may be requested to transmit the 1-cycle data CD. That is, each of the plurality of cores may store the data assigned to each core in the main memory 104 and execute the transmission request to the FPGA 101. In other words, the subject for storing the first period data CD in the main memory 104 and executing the transmission request and the subject for storing the second period data ND in the main memory 104 and executing the transmission request are different entities (for example, for example. It may be another core).

The FPGA 101 (particularly, the acquisition unit 110) transfers the data set in the main memory 104 to the internal RAM 120 of the FPGA 101 (particularly, the transmission queue TXQ of the transmission queue table 121) by the DMA (Dynamic Memory Access) function. Specifically, the FPGA 101 acquires the first period data CD from the main memory 104, and buffers the acquired first period data CD in the first transmission queue TXQ0. Similarly, the FPGA 101 acquires the second period data ND from the main memory 104, and buffers the acquired second period data ND in the second transmission queue TXQ1.

Here, when the second cycle data ND is buffered in the second transmission queue TXQ1, the FPGA 101 (particularly, the first generation unit 140) transmits the second cycle data ND stored in the second transmission queue TXQ1. The basic period Bb is calculated from the data length.

Further, the FPGA 101 (particularly, the second generation unit 150) acquires the transmission start time S (n) of the first cycle data CD of the Nth cycle when the transmission of the first cycle data CD of the Nth cycle is started. Then, the acquired transmission start time S (n) is compared with the reference time T (n) in the Nth cycle. Then, when the transmission start time S (n) and the reference time T (n) do not match, the FPGA 101 calculates the difference period V (n), which is the difference between the two.

When the transmission start time S (n) of the Nth cycle is later than the reference time T (n) of the Nth cycle, the FPGA 101 (particularly, the setting unit 160) prohibits the N + 1th front transmission of the difference period V (n). Set as a period. That is, when the transmission start time S (n) is later than the reference time T (n), the setting unit 160 sets the difference period V (n) as the adjustment period Ba (n + 1) before the reference time T (n + 1). Set. The front transmission prohibition period is a transmission prohibition period B that is additionally set in addition to the basic period Bb before the reference time T, and is a period during which transmission start of the second cycle data ND is prohibited.

Specifically, the FPGA 101 is described as "a period in which the" transmission start time S (n) is delayed from the reference time T (n) in the basic period Bb (= difference period V (n)) before the reference time T (n + 1). )) ”Is added as the transmission prohibition period B (n + 1). That is, the FPGA 101 prohibits transmission so that the end point of the period including the total period of the difference period V (n) (= adjustment period Ba (n + 1)) and the basic period Bb (n + 1) becomes the reference time T (n + 1). Set the period B (n + 1).

When the transmission start time S (n) of the Nth cycle is earlier than the reference time T (n) of the Nth cycle, the FPGA 101 (particularly, the setting unit 160) transmits the difference period V (n) to the N + 1th rear side transmission. Set as a prohibited period. That is, when the transmission start time S (n) is earlier than the reference time T (n), the setting unit 160 sets the difference period V (n) as the adjustment period Ba (n + 1) after the reference time T (n + 1). do. The rear transmission prohibition period is a transmission prohibition period B set after the reference time T, and is a period during which transmission start of the second cycle data ND is prohibited.

Specifically, the FPGA 101 sets the basic period Bb as the transmission prohibition period B (n + 1) before the reference time T (n + 1). Further, the FPGA 101 prohibits transmission of "a period in which the transmission start time S (n) is earlier than the reference time T (n) in the Nth cycle (= difference period V (n))" after the reference time T (n + 1). It is set as the period B (n + 1). That is, the FPGA 101 sets the transmission prohibition period B (n + 1) so that the end point of the basic period Bb (n + 1) becomes the reference time T (n + 1). Further, the FPGA 101 sets the transmission prohibition period B (n + 1) so that the start point of the difference period V (n) (= adjustment period Ba (n + 1)) becomes the reference time T (n + 1).

Regarding the second cycle data ND that is ready for transmission, the FPGA 101 (particularly, the second transmission unit 170 (2)) is not in the transmission of the first cycle data CD or in the transmission prohibition period B, the second cycle data ND. Start sending. The FPGA 101 does not start the transmission of the second cycle data ND if the transmission of the first cycle data CD or the transmission prohibition period B is in progress. After the transmission of the first cycle data CD is completed, the FPGA 101 cancels the transmission prohibition period B, for example, and starts the transmission of the second cycle data ND.

(Functional block of FPGA)
The FPGA 101 includes an acquisition unit 110, a calculation unit 130, a first generation unit 140, a second generation unit 150, a setting unit 160, a transmission unit 170, an instruction unit 180, and a notification unit 190 as functional blocks.

The acquisition unit 110 acquires the first cycle data CD and the transmission start time S of the first cycle data CD from, for example, the main memory 104 via the chipset 102. Then, the acquisition unit 110 stores the acquired first period data CD and the transmission start time S in the first transmission queue TXQ0 of the transmission queue table 121, in other words, sets them in the first transmission queue TXQ0.

Here, the transmission start time S is a scheduled time for starting transmission of the first cycle data CD, which is high priority data to be transmitted at a fixed cycle. The transmission start time S is set in the main memory 104 by the host system together with the first cycle data CD, and is stored in the main memory 104 together with the first cycle data CD by the microprocessor 103 via the chipset 102, for example.

Further, the acquisition unit 110 acquires the second period data ND via the chipset 102, for example, from the main memory 104, and stores the acquired second period data ND in the second transmission queue TXQ1 of the transmission queue table 121. do. The acquisition unit 110 acquires the transmission start time of the second cycle data ND and the second cycle data ND from the main memory 104, and the transmission start time of the acquired second cycle data ND and the second cycle data ND. May be stored in the second transmission queue TXQ1. However, in the following description, in order to facilitate the understanding of the PLC10 that "the transmission start of the first cycle data CD is secured at the transmission start time S", the transmission start time of the second cycle data ND is described. No particular explanation will be given.

The calculation unit 130 calculates a "reference time T (= reference time)" which is a time obtained by adding a time interval corresponding to the transmission cycle C of the first cycle data CD to be periodically transmitted to the transmission start time S. For example, the calculation unit 130 sets the time obtained by adding the "time interval corresponding to the transmission cycle C" to the transmission start time S (n) of the first cycle data CD in the Nth cycle as the reference time T in the N + 1th cycle (N + 1 cycle). n + 1). It should be noted that "T (0) = S (0)". The calculation unit 130 stores the calculated reference time T (for example, the reference time T (n + 1) in the N + 1 cycle) in the reference time table 122.

When the second cycle data ND is buffered in the second transmission queue TXQ1, the first generation unit 140 determines the amount of data in the second cycle data ND stored in the second transmission queue TXQ1 (for example, the transmission data length). From, the basic period Bb is calculated. The basic period Bb is, for example, "the time required to transmit the second period data ND". The first generation unit 140 notifies the setting unit 160 of the calculated basic period Bb.

The second generation unit 150 acquires the transmission start time S (n) of the first cycle data CD in the Nth cycle, refers to, for example, the first transmission queue TXQ0, and puts the first cycle data in the first transmission queue TXQ0. Acquires the transmission start time S (n) set together with the CD. Further, the second generation unit 150 acquires the reference time T (n) in the Nth cycle with reference to the reference time table 122.

The second generation unit 150 compares the transmission start time S (n) of the first cycle data CD in the Nth cycle with the reference time T (n) in the Nth cycle of the Nth cycle, and when they do not match. , The difference period V (n), which is the difference between the two, is calculated, and the calculated difference period V (n) is notified to the setting unit 160.

In this embodiment, as a general rule, the "transmission start time S", which is the time when the first cycle data CD should be transmitted, and the first transmission unit 170 (1) actually transmit the first cycle data CD. It shall be the same as the start time (actual transmission start time). In a certain control cycle M, when the "transmission start time S (m)" which is the time when the first cycle data CD should be transmitted and the actual transmission start time of the first cycle data CD do not match, the second generation unit In 150, the difference period V (n) is calculated as follows. That is, the second generation unit 150 is the difference between the "transmission start time S (m), which is the time when the first cycle data CD should be transmitted in the control cycle M" and the "reference time T (M) of the control cycle M". May be calculated as the difference period V (n). Further, the second generation unit 150 sets the difference between the "actual transmission start time of the first cycle data CD in the control cycle M" and the "reference time T (M) of the control cycle M" in the difference period V (n). It may be calculated as. When the "actual transmission start time of the first period data CD" is used for the calculation of the difference period V (n), the second generation unit 150 is referred to from the transmission unit 170 (particularly, the first transmission unit 170 (1)). The "actual transmission start time of the first cycle data CD in each control cycle (= each transmission cycle)" may be acquired.

The setting unit 160 has a basic period Bb notified by the first generation unit 140 and a difference period V (notified by the second generation unit 150) with respect to the reference time T acquired by referring to the reference time table 122. Using n), the transmission prohibition period B (n + 1) in the N + 1th cycle is set.

When the "difference period V (n) = 0", the setting unit 160 determines that the reference time T (n) and the transmission start time S (n) match. Then, the setting unit 160 sets a period including the basic period Bb (n + 1) as the transmission prohibition period B (n + 1) so that the reference time T (n + 1) in the N + 1 cycle becomes the end point. For example, the setting unit 160 has a transmission prohibition period B (transmission prohibition period B) starting from "a time retroactive from the reference time T (n + 1) to the basic period Bb (n + 1)" and ending at "reference time T (n + 1)". Set to n + 1).

When the "difference period V (n)> 0", the setting unit 160 determines that the transmission start time S (n) is later than the reference time T (n). Then, the setting unit 160 sets the difference period V (n) as the N + 1th front transmission prohibition period (that is, the adjustment period Ba (n + 1)). Specifically, in the setting unit 160, the end point of the period including the total period of the difference period V (n) (= adjustment period Ba (n + 1)) and the basic period Bb (n + 1) is the reference time T (n + 1). As described above, the transmission prohibition period B (n + 1) is set. That is, before the reference time T (n + 1), the setting unit 160 states that "in the basic period Bb," the transmission start time S (n) is delayed from the reference time T (n) in the Nth cycle (= difference period). The period in which "V (n))" is added is set as the transmission prohibition period B (n + 1). For example, the setting unit 160 starts from "a time retroactive from the reference time T (n + 1) to the" total period of the difference period V (n) (= adjustment period Ba (n + 1)) and the basic period Bb (n + 1) "". Then, the period ending from the "reference time T (n + 1)" is set to the transmission prohibition period B (n + 1).

When the "difference period V (n) <0", the setting unit 160 determines that the transmission start time S (n) is earlier than the reference time T (n). Then, the setting unit 160 sets the difference period V (n) as the N + 1th rear transmission prohibition period (that is, the adjustment period Ba (n + 1)). Specifically, the setting unit 160 sets the transmission prohibition period B (n + 1) so that the end point of the basic period Bb (n + 1) becomes the reference time T (n + 1). Further, the setting unit 160 sets the transmission prohibition period B (n + 1) so that the start point of the difference period V (n) (= adjustment period Ba (n + 1)) becomes the reference time T (n + 1). For example, the setting unit 160 starts from "the time retroactive from the reference time T (n + 1) to the basic period Bb (n + 1)" and sets "the time when the adjustment period Ba (n + 1) has elapsed from the reference time T (n + 1)". The period to be the end point is set to the transmission prohibition period B (n + 1).

The transmission unit 170 controls data transmission, and controls, for example, transmission of the first cycle data CD set in the first transmission queue TXQ0 and the second cycle data ND set in the second transmission queue TXQ1. The first transmission unit 170 (1) and the second transmission unit 170 (2) are included.

The first transmission unit 170 (1) controls the transmission of the first cycle data CD, and specifically, the transmission of the first cycle data CD set in the first transmission queue TXQ0 is transmitted together with the first cycle data CD. It starts at the transmission start time S set in the first transmission queue TXQ0. The first transmission unit 170 (1) cannot transmit the first cycle data CD while the second cycle data ND is being transmitted.

The second transmission unit 170 (2) controls the transmission of the second cycle data ND, and specifically, the transmission of the second cycle data ND set in the second transmission queue TXQ1 is "the first cycle data CD. It starts in a period other than "the period during transmission and the period of transmission prohibition B". That is, in the "period during transmission of the first cycle data CD" and the "period during the transmission prohibition period B", the second transmission unit 170 (2) does not start the transmission of the second cycle data ND. When the second transmission unit 170 (2) cannot continuously transmit the second cycle data ND in the transmittable state over a predetermined number of control cycles, the second transmission unit 170 (2) continuously transmits the second cycle data ND over a predetermined number of control cycles. Notify the instruction unit 180 and the notification unit 190 that "the transmission has not been completed". In other words, the second transmission unit 170 (2) notifies the indicator unit 180 of the situation when the second cycle data ND cannot be continuously transmitted over a predetermined number of control cycles after being set in the second transmission queue TXQ1. Notify department 190.

The instruction unit 180 instructs the second transmission unit 170 (2) to start the transmission of the second cycle data ND even during the transmission prohibition period B, that is, the forced transmission of the second cycle data ND. To instruct. The instruction unit 180 indicates from the second transmission unit 170 (2) that "the second cycle data ND has not been continuously transmitted over a predetermined number of control cycles since the second cycle data ND became ready for transmission". Upon being notified, the second transmission unit 170 (2) may be automatically instructed to perform forced transmission. Further, when the user instructs the instruction unit 180 to forcibly transmit the second cycle data ND, the instruction unit 180 may instruct the second transmission unit 170 (2) to perform the forced transmission. Upon receiving this instruction from the instruction unit 180, the second transmission unit 170 (2) starts transmitting the second period data ND set in the second transmission queue TXQ1 even during the transmission prohibition period B.

The notification unit 190 indicates from the second transmission unit 170 (2) that "the second cycle data ND has not been continuously transmitted over a predetermined number of control cycles since the second cycle data ND became capable of transmission". When notified, it instructs the execution of the following processing. That is, the notification unit 190 notifies the analysis device 50 that "the second cycle data ND has not been continuously transmitted over a predetermined number of control cycles", for example, via the microprocessor 103 or the like. The analysis device 50 is displayed to that effect.

(Memory unit provided by FPGA)
The FPGA 101 illustrated in FIG. 1 includes an internal RAM 120. The internal RAM 120 is a storage device for storing various data used by the FPGA 101. The internal RAM 120 non-temporarily stores a control program for various processes executed by the FPGA 101 and various data to be read when the control program is executed. The internal RAM 120 further stores a transmission queue table 121, a reference time table 122, and setting information 123.

The transmission queue table 121 includes a plurality of transmission queues TXQ0, TXQ1, ..., TXQn. In the following description, when it is not necessary to distinguish each of the plurality of transmission queues TXQ0, TXQ1, ..., TXQn, it is simply referred to as "transmission queue TXQ". The transmission data from the host system is buffered in the transmission queue TXQ. For example, the transmission data set in the main memory 104 by the microprocessor 103 via the chipset 102 is set in the transmission queue TXQ by the acquisition unit 110. Will be done.

For example, the first cycle data CD and the transmission start time S of the first cycle data CD are buffered in the first transmission queue TXQ0 (in other words, the first cycle data CD and the transmission start time S). And are set). Similarly, the second period data ND is buffered (that is, set) in the second transmission queue TXQ1.

When the set of transmission data to the transmission queue TXQ is completed, the transmission data is ready to start transmission to an actual network line such as the field network 20 and the PLC system bus 400. The transmit queue TXQ employs, for example, a FIFO (first in, first out, first in, first out) method.

The internal RAM 120 may further store a reception queue table (not shown) in which data received from the outside of the CPU unit 100 is stored. The receive queue table includes a plurality of receive queues RXQ0, RXQ1, ..., RXQn, and each of RXQ0, RXQ1, ..., RXQn may adopt a FIFO method.

The reference time T calculated by the calculation unit 130 is stored in the reference time table 122. The reference time T is calculated as a reference for setting the transmission prohibition period B instead of the transmission start time S, and specifically, is calculated (= generated) by the calculation unit 130.
The calculation unit 130 adds, for example, "T (0) = S (0)" to "the transmission start time S in a certain control cycle" and "the time interval corresponding to the transmission cycle C of the first cycle data CD". The time is calculated as "reference time T in the next control cycle". Then, the calculation unit 130 stores the calculated "reference time T in the next control cycle" in the reference time table 122.

The setting information 123 stores various setting information related to the operation of the control system 1, including the transmission cycle C. The transmission cycle C is also referred to as a “control cycle” and is a transmission time interval of the first cycle data CD which is high priority data to be transmitted at a fixed cycle. The FPGA 101 acquires the transmission cycle C by one of the following two methods. That is, the FPGA 101 may store the time interval notified from the host system (specifically, from the microprocessor 103 via the chipset 102) in the setting information 123 as the transmission cycle C. Further, the FPGA 101 calculates an average time interval between the transmission start times S of the first cycle data CD for a predetermined number of control cycles (for example, N cycles), and uses the calculated average time interval as the transmission cycle C. It may be stored in the setting information 123.

Regarding the CPU unit 100 (particularly FPGA101) whose outline has been described so far, the outline of the processing executed by the CPU unit 100 (particularly FPGA101) will be described next with reference to FIG. 3 and the like.

§3. Operation example (Overview of the processing executed by PLC10)
FIG. 3 is a flow chart showing an overall outline of the processing executed by the CPU unit 100 (particularly, FPGA 101). As illustrated in FIG. 3, the calculation unit 130 acquires the transmission start time S (n) in the Nth cycle (S100), and adds a time corresponding to the transmission cycle C to the acquired transmission start time S (n). Then, the reference time T (n + 1) in the N + 1 cycle is calculated (S200). The calculation unit 130 stores the calculated reference time T (n + 1) in the reference time table 122.

The first generation unit 140 and the second generation unit 150 execute the transmission prohibition period calculation process (S300). The details of the transmission prohibition period calculation process will be described later with reference to FIG. Further, the setting unit 160 executes the transmission prohibition period setting process (S400). The details of the transmission prohibition period setting process will be described later with reference to FIG.

The second transmission unit 170 (2) confirms whether the second period data ND is stored in the second transmission queue TXQ1 (S500). When it is confirmed that the second cycle data ND is not stored in the second transmission queue TXQ1 (No in S500), that is, when it is confirmed that there is no second cycle data ND in the transmittable state, the setting is made. Unit 160 ends the process, that is, the transmission prohibition period B is not set. Since there is no second cycle data ND in the transmittable state, the second transmission unit 170 (2) does not start the transmission of the second cycle data ND. Further, the first transmission unit 170 (1) transmits the transmission of the first cycle data CD set in the first transmission queue TXQ0 together with the first cycle data CD in the first transmission queue TXQ0 at the transmission start time S. To start.

When it is confirmed that the second period data ND is stored in the second transmission queue TXQ1 (Yes in S500), the second transmission unit 170 (2) confirms whether the transmission prohibition period B is in progress (Yes). S600). When the second transmission unit 170 (2) confirms that the transmission prohibition period B is in progress (Yes in S600), the second transmission unit 170 (2) is in a period other than the transmission prohibition period B after the transmission of the first period data CD is completed. Transmission of periodic data ND is started (S700). When the second transmission unit 170 (2) confirms that the transmission prohibition period B is not in progress (No in S600), the second transmission unit 170 (2) starts transmission of the second cycle data ND (S800).

The processing flow illustrated in FIG. 3 can be organized as follows. That is, the control method executed by the PLC 10 (particularly the FPGA 101) is a control method of the control device that outputs the first cycle data CD for each control cycle (specifically, the transmission cycle C), and is the first cycle data. The acquisition step (S100) for acquiring the CD together with the transmission start time S of the first cycle data CD, and the first cycle to be transmitted in the control cycle (= transmission cycle C) of the Nth cycle with N as a natural number of 0 or more. A calculation step (S200) for calculating the reference time T (n + 1) in the N + 1 cycle by adding a time interval corresponding to the transmission cycle C to the transmission start time S (n) of the data CD, and control of the N cycle. The transmission prohibition period B (n + 1) generated by using the difference between the transmission start time S (n) of the first cycle data CD to be transmitted in the cycle and the reference time T (n) of the Nth cycle is set to the N + 1 cycle. Priority is given to the first cycle data CD during the setting step (S400) set at least one before and after the reference time T (n + 1) of the eye and the period other than the transmission prohibition period B (n + 1) set in the setting step. A transmission step (S700) for initiating transmission of the second period data ND having a low degree is included.

According to the above method, in the control method, the difference between the transmission start time S (n) of the first cycle data CD to be transmitted in the control cycle of the Nth cycle and the reference time T (n) of the Nth cycle. In consideration of the above, the transmission prohibition period B (n + 1) for prohibiting the start of transmission of the second period data ND is calculated. Then, the control method is at least before and after the reference time T (n + 1) in the N + 1th cycle, which is calculated by adding the time interval corresponding to the transmission cycle C to the transmission start time S (n) in the Nth cycle. On the other hand, the transmission prohibition period B (n + 1) is set. Then, the control method starts the transmission of the second period data ND during a period other than the transmission prohibition period B (n + 1). That is, in the control method, even when the transmission start time S (n) in the Nth cycle and the reference time T (n) deviate from each other, the transmission start time S and the reference time T (n) in the Nth cycle The transmission prohibition period B (n + 1) in consideration of the difference is set at least one before and after the reference time T (n + 1) in the N + 1 cycle.

Therefore, in the control method, even when the transmission start time S (n) and the reference time T (n) in the Nth cycle deviate from each other, an appropriate transmission prohibition period B (n + 1) is set in consideration of the difference between the two. Then, the transmission of the first cycle data CD can be started at the transmission start time S (n + 1) in the N + 1th cycle.

(Details of transmission prohibition period calculation process)
FIG. 4 is a flow chart illustrating the details of the transmission prohibition period calculation process of FIG. As illustrated in FIG. 4, first, the second generation unit 150 acquires the transmission start time S (n) of the first cycle data CD in the Nth cycle (S310). The second generation unit 150 may refer to the first transmission queue TXQ0 and acquire the transmission start time S (n) set in the first transmission queue TXQ0 together with the first period data CD. Further, the second generation unit 150 sets the "actual transmission start time of the first period data CD" from the transmission unit 170 (particularly, the first transmission unit 170 (1)) as the transmission start time S (n). You may get it.

Further, the second generation unit 150 acquires the reference time T (n) in the Nth cycle with reference to the reference time table 122 (S320). The second generation unit 150 compares the acquired transmission start time S (n) with the reference time T (n), and the transmission start time S (n) in the Nth cycle and the reference time T (n) in the Nth cycle. The difference from (= difference period V (n)) is calculated (S330). The second generation unit 150 calculates the difference period V (n) as, for example, "difference period V (n) = transmission start time S (n) -reference time T (n)". The second generation unit 150 notifies the setting unit 160 of the calculated difference period V (n).

The first generation unit 140 measures the amount of data of the second cycle data ND set in the second transmission queue TXQ1 (S340), and the period required for transmitting the second cycle data ND (= basic period Bb (n + 1)). Is calculated (S350). The first generation unit 140 notifies the setting unit 160 of the calculated basic period Bb (n + 1).

(Details of transmission prohibition period setting process)
FIG. 5 is a flow chart illustrating the details of the transmission prohibition period setting process of FIG. As illustrated in FIG. 5, the setting unit 160 confirms whether the reference time T (n) in the Nth cycle and the transmission start time S (n) in the Nth cycle coincide with each other (S410). For example, when the difference period V (n) notified from the second generation unit 150 is “difference period V (n) = 0”, the setting unit 160 sets the reference time T (n) and the transmission start time S ( It is determined that n) and the same, and if the difference period V (n) is not 0, it is determined that the two do not match.

When it is confirmed that the reference time T (n) and the transmission start time S (n) match (that is, the difference period V (n) is 0) (Yes in S410), the setting unit 160 is as follows. The transmission prohibition period B (n + 1) is set in. That is, the setting unit 160 sets the period including the basic period Bb (n + 1) as the transmission prohibition period B (n + 1) so that the reference time T (n + 1) in the N + 1 cycle becomes the end point (S420). For example, the setting unit 160 has a transmission prohibition period B (transmission prohibition period B) starting from "a time retroactive from the reference time T (n + 1) to the basic period Bb (n + 1)" and ending at "reference time T (n + 1)". Set as n + 1).

When it is confirmed that the reference time T (n) and the transmission start time S (n) do not match (that is, the difference period V (n) is not 0) (No in S410), the setting unit 160 sets the Nth cycle. It is determined whether the transmission start time S (n) in the Nth cycle is later than the reference time T (n) (S430). When the setting unit 160 is "difference period V (n) = transmission start time S (n) -reference time T (n)> 0", the setting unit 160 transmits the Nth cycle from the reference time T (n) of the Nth cycle. It may be determined that the start time S (n) is late. Further, if the setting unit 160 determines that the "difference period V (n) <0", the transmission start time S (n) in the Nth cycle is earlier than the reference time T (n) in the Nth cycle. good.

When it is confirmed that the transmission start time S (n) is later than the reference time T (n) (that is, "difference period V (n)> 0") (Yes in S430), the setting unit 160 transmits as follows. The prohibition period B (n + 1) is set. That is, the setting unit 160 includes the sum of the basic period Bb (n + 1) and the adjustment period Ba (n + 1) (= difference period V (n)) so that the reference time T (n + 1) in the N + 1 cycle becomes the end point. The period is set as the transmission prohibition period B (n + 1) (S440). For example, the setting unit 160 starts from "a time retroactive from the reference time T (n + 1) to the total period of the basic period Bb (n + 1) and the adjustment period Ba (n + 1)" as the "reference time T (n + 1)". Is set as the transmission prohibition period B (n + 1).

When it is confirmed that the transmission start time S (n) is earlier than the reference time T (n) (that is, "difference period V (n) <0") (No in S430), the setting unit 160 transmits as follows. The prohibition period B (n + 1) is set. That is, the setting unit 160 sets the transmission prohibition period B to the period including the basic period Bb (n + 1) so that the reference time T (n + 1) in the N + 1 cycle becomes the end point (S450). For example, the setting unit 160 has a transmission prohibition period B (transmission prohibition period B) starting from "a time retroactive from the reference time T (n + 1) to the basic period Bb (n + 1)" and ending at "reference time T (n + 1)". Set as n + 1).

Further, the setting unit 160 sets the transmission prohibition period B (n + 1) for a period including the adjustment period Ba (n + 1) (= difference period V (n)) so that the reference time T (n + 1) in the N + 1 cycle becomes the starting point. Is set as (S460). For example, the setting unit 160 sets a period starting from "reference time T (n + 1)" and ending at "time after the adjustment period Ba (n + 1) has elapsed from reference time T (n + 1)" as a transmission prohibition period B (transmission prohibition period B). Set as n + 1).

By S450 and S460, the starting point is "the time retroactive from the reference time T (n + 1) to the basic period Bb (n + 1)", and the end point is "the time when the adjustment period Ba (n + 1) has elapsed from the reference time T (n + 1)". The period to be performed is set as the transmission prohibition period B (n + 1).

As described with reference to FIGS. 3 to 5, the PLC 10 sets the length of the transmission prohibition period B (n + 1) set in the N + 1 cycle according to the transmission state of the first cycle data CD in the N cycle. It is dynamically changed and the transmission prohibition period B (n + 1) of the optimum length is set. Hereinafter, a specific processing example executed by the PLC 10 will be described with reference to FIGS. 6 and 7.

(Processing example 1 In the Nth cycle, when the transmission start time S is later than the reference time T)
FIG. 6 shows an example of processing executed by the PLC 10 (particularly, FPGA 101) when the transmission start time S (n) is later than the reference time T (n) in the Nth cycle, in comparison with the conventional adjustment method. It is a figure explaining.

That is, (A) in FIG. 6 is the same as (A) in FIG. 9, that is, the transmission start time S (n) in the Nth cycle is delayed from the reference time T (n) in the Nth cycle. For cases, problems that occur in the prior art are shown. As shown in FIG. 6A, when the transmission start time S (n) in the Nth cycle is later than the reference time T (n) in the Nth cycle, “transmission” is performed at the transmission start time S (n). The reference time T (n + 1), which is the time to which the "time interval corresponding to the cycle C" is added, shows the following tendency. That is, the reference time T (n + 1) in the N + 1 cycle tends to be later than the transmission start time S (n + 1) in the N + 1 cycle. Here, in the prior art, the "time required for transmission of the second period data ND" is set as the transmission prohibition period B before the reference time T (n + 1). That is, in the prior art, a time later than the transmission start time S (n + 1) is set as a reference time T (n + 1), and before the reference time T (n + 1), "time required for transmission of the second cycle data ND". The transmission prohibition period B is set.

As described above, by setting the period from "the time retroactive from the transmission start time S (n + 1) to the time required for transmission of the second period data ND" to "the transmission start time S (n + 1)" as the transmission prohibition period B. , The transmission of the first period data CD can be started at the transmission start time S (n + 1). However, in FIG. 6A, the transmission prohibition period B, which is the “time required for transmission of the second period data ND”, is before the reference time T (n + 1), which is later than the transmission start time S (n + 1). Is set. That is, the transmission prohibition period B set by the prior art before the reference time T (n + 1) is the “transmission start time” from the “time retroactive from the transmission start time S (n + 1) to the time required to transmit the second cycle data ND”. It is later than the period until "time S (n + 1)".

As a result, the time when the second cycle data ND becomes transmitable is not included in the "period during transmission of the first cycle data CD" or the "period of the transmission prohibition period B", and is the second. Transmission of the periodic data ND is started immediately after the transmission becomes ready. In FIG. 6A, the time when the transmission of the second period data ND is completed is later than the transmission start time S (n + 1), and the first period data CD cannot be transmitted while the second period data ND is being transmitted. The transmission of the first period data CD cannot be started at the start time S (n + 1).

FIG. 6B is a diagram illustrating a transmission prohibition period B (n + 1) set by the PLC 10 when the transmission start time S (n) is later than the reference time T (n). When the transmission start time S (n) in the Nth cycle is later than the reference time T (n) in the Nth cycle, the FPGA 101 (particularly, the setting unit 160) has the transmission start time S (n) and the reference time T (n). The difference period V (n), which is the difference period with and from, is set as the N + 1th front transmission prohibition period. That is, the setting unit 160 sets the reference time T (n + 1) at the end point of the period including the total period of the difference period V (n) (= adjustment period Ba (n + 1)) and the basic period Bb (n + 1). The transmission prohibition period B (n + 1) is set.

By setting the transmission prohibition period B (n + 1) including the total period of the adjustment period Ba (n + 1) and the basic period Bb (n + 1) so that the end point becomes the reference time T (n + 1), (1) in FIG. In B), the transmission of the second period data ND is appropriately prohibited. That is, in (B) of FIG. 6, a transmission prohibition period B (n + 1) longer than the transmission prohibition period B (n + 1) of FIG. 6 (A) by the adjustment period Ba (n + 1) is set.

In FIG. 6A, since "prohibiting the start of transmission of the second cycle data ND by an appropriate transmission prohibition period B (n + 1)" fails, the first transmission of the second cycle data ND causes the first. The transmission start of the periodic data CD is delayed from the transmission start time S (n + 1). On the other hand, in FIG. 6A, it is possible to "prohibit the start of transmission of the second cycle data ND by an appropriate transmission prohibition period B (n + 1)", and the transmission of the first cycle data CD is performed. , The transmission start time S (n + 1).

(Processing example 2 In the Nth cycle, when the transmission start time S is earlier than the reference time T)
FIG. 7 shows an example of the processing executed by the PLC 10 (particularly the FPGA 101) when the transmission start time S (n) is earlier than the reference time T (n) in the Nth cycle, in comparison with the conventional adjustment method. It is a figure explaining.

That is, (A) in FIG. 7 is the same as (B) in FIG. 9, that is, when the transmission start time S (n) in the Nth cycle is earlier than the reference time T (n) in the Nth cycle. It is a figure explaining the problem which occurs in the prior art. As shown in FIG. 7A, when the transmission start time S (n) in the Nth cycle is earlier than the reference time T (n) in the Nth cycle, the “transmission cycle” is set to the transmission start time S (n). The reference time T (n + 1), which is the time to which the "time interval corresponding to C" is added, shows the following tendency. That is, the reference time T (n + 1) in the N + 1 cycle tends to be earlier than the transmission start time S (n + 1) in the N + 1 cycle. Here, in the prior art, the "time required for transmission of the second period data ND" is set as the transmission prohibition period B before the reference time T (n + 1). That is, in the prior art, a time earlier than the transmission start time S (n + 1) is set as the reference time T (n + 1), and before the reference time T (n + 1), the "time required for transmission of the second cycle data ND" is used. A certain transmission prohibition period B is set.

As described above, by setting the period from "the time retroactive from the transmission start time S (n + 1) to the time required for transmission of the second period data ND" to "the transmission start time S (n + 1)" as the transmission prohibition period B. , The transmission of the first period data CD can be started at the transmission start time S (n + 1). However, in FIG. 7A, the transmission prohibition period B, which is the “time required for transmission of the second period data ND”, is set before the reference time T (n + 1) earlier than the transmission start time S (n + 1). It is set. That is, the transmission prohibition period B set by the prior art before the reference time T (n + 1) is the “transmission start time” from the “time retroactive from the transmission start time S (n + 1) to the time required to transmit the second cycle data ND”. It is earlier than the period until "time S (n + 1)".

As a result, the time when the second cycle data ND becomes transmitable is not included in the "period during transmission of the first cycle data CD" or the "period of the transmission prohibition period B", and is the second. Transmission of the periodic data ND is started immediately after the transmission becomes ready. In FIG. 7A, the time when the transmission of the second cycle data ND is completed is later than the transmission start time S (n + 1), and the first cycle data CD cannot be transmitted while the second cycle data ND is being transmitted. The transmission of the first period data CD cannot be started at the start time S (n + 1).

FIG. 7B is a diagram illustrating a transmission prohibition period B (n + 1) set by the PLC 10 when the transmission start time S (n) is earlier than the reference time T (n). When the transmission start time S (n) in the Nth cycle is earlier than the reference time T (n) in the Nth cycle, the FPGA 101 (particularly, the setting unit 160) has the transmission start time S (n) and the reference time T (n). The difference period V (n), which is the difference period with and from, is set as the N + 1th rear transmission prohibition period. That is, the setting unit 160 sets the difference period V (n) (= adjustment period Ba (n + 1)) after the reference time T (n + 1), and the start point of the difference period V (n) becomes the reference time T (n + 1). As described above, the transmission prohibition period B (n + 1) is set. Specifically, the setting unit 160 sets the time from "reference time T (n + 1)" to "time after the difference period V (n) (= adjustment period Ba (n + 1)) from the reference time T (n + 1)". It is set as the transmission prohibition period B (n + 1).

Further, the setting unit 160 sets the basic period Bb (n + 1) as the transmission prohibition period B (n + 1) so that the end point of the basic period Bb (n + 1) becomes the reference time T (n + 1). Specifically, the setting unit 160 sets the transmission prohibition period B (n + 1) from the “time retroactive from the reference time T (n + 1) to the basic period Bb (n + 1)” to the “reference time T (n + 1)”. do.

Therefore, the setting unit 160 sets the time from "the time retroactive from the reference time T (n + 1) to the basic period Bb (n + 1)" to "the time after the adjustment period Ba (n + 1) has elapsed from the reference time T (n + 1)". It is set as the transmission prohibition period B (n + 1).

The transmission prohibition period B (n + 1) is from "the time retroactive from the reference time T (n + 1) to the basic period Bb (n + 1)" to "the time when the adjustment period Ba (n + 1) has elapsed from the reference time T (n + 1)". By setting as, in FIG. 7B, the transmission of the second period data ND is appropriately prohibited. That is, in FIG. 7B, a transmission prohibition period B (n + 1) longer than the transmission prohibition period B (n + 1) in FIG. 7 (A) by the adjustment period Ba (n + 1) is set.

In FIG. 7A, since "prohibiting the start of transmission of the second cycle data ND by an appropriate transmission prohibition period B (n + 1)" fails, the first transmission of the second cycle data ND causes the first. The transmission start of the periodic data CD is delayed from the transmission start time S (n + 1). On the other hand, in FIG. 7A, it is possible to "prohibit the start of transmission of the second cycle data ND by an appropriate transmission prohibition period B (n + 1)", and the transmission of the first cycle data CD is performed. , The transmission start time S (n + 1).

(Notification processing and forced transmission processing)
For example, when attempting to transmit second cycle data ND (that is, second cycle data ND with a large amount of data) having a long transmission time with respect to transmission cycle C (= control cycle), transmission of second cycle data ND is performed. The following problems may occur with respect to. That is, the basic period Bb increases in proportion to the amount of data in the second period data ND, and here, the length of the transmission prohibition period B is equal to or greater than the length of the basic period Bb (the transmission prohibition period B is the basic period). Includes the total period of period Bb and adjustment period Ba). Therefore, when the amount of data in the second cycle data ND becomes large, the length of the transmission prohibition period B may be longer than the length of the transmission cycle C (= control cycle). In that case, for example, the transmission prohibition time B always occurs between the transmission start time S (n) of a certain control cycle and the transmission start time S (n + 1) of the next control cycle, and the second cycle data ND cannot be transmitted. The problem can occur.

As a countermeasure, if the second cycle data ND cannot be continuously transmitted over a predetermined number of control cycles, the PLC 10 executes a notification process for notifying the outside of the occurrence of such a situation. Further, the PLC 10 executes a forced transmission process for starting the transmission of the second period data ND regardless of the transmission prohibition period B.

For example, the notification unit 190 continuously detects "a state in which transmission of the second cycle data ND cannot be performed due to the transmission prohibition period B" over a predetermined number of times (for example, M times). Then, the following processing is executed.
That is, the notification unit 190 notifies the host system (for example, the microprocessor 103) of the occurrence of "a state in which the second cycle data ND cannot be continuously transmitted over the M cycle due to the transmission prohibition period B". ,Notice. The host system causes the analysis device 50 connected to the CPU unit 100 to be in a state where the second cycle data ND cannot be continuously transmitted over the M cycle due to the transmission prohibition period B. Notice. When the analysis device 50 receives the notification from the host system, the user is informed of the occurrence of "a state in which the second cycle data ND cannot be continuously transmitted over the M cycle due to the transmission prohibition period B". indicate.

Further, when the host system (for example, the microprocessor 103) receives a user operation instructing the execution of the forced transmission process of the second cycle data ND, the host set 102 executes the forced transmission process of the second cycle data ND, for example. Instruct the FPGA 101 via the like. The FPGA 101 (particularly, the instruction unit 180) instructs the second transmission unit 170 (2) to start the transmission of the second period data ND even during the transmission prohibition period B. According to the instruction from the instruction unit 180, the second transmission unit 170 (2) transmits the second period data ND set in the second transmission queue TXQ1 regardless of whether or not the transmission prohibition period B is set. Start.

§4. Modification example So far, the transmission queue has been described using the first transmission queue TXQ0 and the second transmission queue TXQ1, but it is not essential that there are two transmission queues, and the CPU unit 100 in the PLC 10 (particularly,). The FPGA 101) may include a plurality of transmission queues. That is, a plurality of transmission queues (TXQ0, TXQ1, ... TXQ (n-1)) may be provided in the CPU unit 100 (particularly FPGA101) in the PLC 10.

Further, the CPU unit 100 (particularly FPGA101) in the PLC 10 controls the transmission of data set in each of the plurality of transmission queues (TXQ0, TXQ1, ... TXQ (n-1)), and a plurality of transmissions. It may be provided with a part. For example, the FPGA 101 includes first transmission units 170 (1) to N + 1th transmission units 170 (n) that control the transmission of each of the data set in each of the first transmission queue TXQ0 to the N + 1th transmission queue TXQn. You may.

So far, with N as a natural number of 0 or more, the calculation unit 130 adds a time interval corresponding to the control cycle (= transmission cycle C) to the transmission start time S (n) in the Nth cycle, and is in the N + 1th cycle. An example of calculating the reference time T (n + 1) of the above has been described. Here, with M as a natural number of 1 or more, the calculation unit 130 sets the transmission start time S (n) of the Nth cycle to a period M times the "time interval corresponding to the control cycle (= transmission cycle C)". In addition, the reference time T (n + m) in the N + M cycle may be calculated.

Further, as described above, the FPGA 101 may be notified of the transmission cycle C from the microprocessor 103 or the like, and calculates the average time interval between the transmission start times S of the first cycle data CD for a predetermined number of control cycles. Then, the calculated average time interval may be used as the transmission cycle C. Here, when the transmission cycle C is calculated from the average time interval between the transmission start times S of the plurality of first cycle data CDs, and when there is no first cycle data CD to be transmitted in a certain control cycle, the transmission cycle C The FPGA 101 executes the following processing in order to accurately calculate. That is, when there is no first cycle data CD to be transmitted in the Pth control cycle, the FPGA 101 has a transmission start time S (p-1) in the P-1st control cycle and a transmission start in the P + 1st control cycle. The time interval between time S (p + 1) is not used in the calculation of the transmission cycle C.

So far, the acquisition unit 110, the internal RAM 120, the calculation unit 130, the first generation unit 140, the second generation unit 150, the setting unit 160, the transmission unit 170, the instruction unit 180, and the notification unit 190 have been FPGA (Field-Programmable). We have explained an example realized in gate array). However, it is not essential that these functional blocks are realized by using FPGA, and may be realized by using, for example, ASIC (Application Specific Integrated Circuit). That is, the acquisition unit 110, the internal RAM 120, the calculation unit 130, the first generation unit 140, the second generation unit 150, the setting unit 160, the transmission unit 170, the instruction unit 180, and the notification unit 190 are realized by using the ASIC. You may.

The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the claims, and the embodiments obtained by appropriately combining the technical means disclosed in the different embodiments. Is also included in the technical scope of the present invention.

10 PLC (control device)
110 Acquisition unit 130 Calculation unit 140 1st generation unit 150 2nd generation unit 160 Setting unit 170 2nd transmission unit (transmission unit)
180 Indicator 190 Notification B Transmission prohibition period C Transmission cycle (control cycle)
S Transmission start time T Reference time Ba Adjustment period Bb Basic period CD 1st cycle data ND 2nd cycle data S100 Acquisition step S200 Calculation step S400 Setting step S700 Transmission step

Claims (7)

It is a control device that outputs the first cycle data for each control cycle.
An acquisition unit that acquires the first period data together with the transmission start time of the first period data, and
The reference time for the N + 1 cycle is calculated by adding a time interval corresponding to the control cycle to the transmission start time of the first cycle data to be transmitted in the control cycle of the N cycle, where N is a natural number of 0 or more. Calculation unit and
The transmission prohibition period generated by using the difference between the transmission start time of the first cycle data to be transmitted in the control cycle of the Nth cycle and the reference time of the Nth cycle is set before the reference time of the N + 1th cycle and The setting part to be set on at least one of the back and
A transmission unit that starts transmission of second period data having a lower priority than the first period data during a period other than the transmission prohibition period set by the setting unit.
A first generation unit that generates a basic period, which is a period required for transmission of the second period data, from the amount of data of the second period data.
A second generation unit that generates an adjustment period that is the difference between the transmission start time of the first cycle data to be transmitted in the control cycle of the Nth cycle and the reference time of the Nth cycle.
Equipped with
The transmission prohibition period set by the setting unit includes the total period of the basic period and the adjustment period.
When the transmission start time of the first cycle data to be transmitted in the control cycle of the Nth cycle is later than the reference time of the Nth cycle, the setting unit sets the end point so that the reference time of the N + 1th cycle becomes the end point. A control device characterized in that a period including a total period of the basic period and the adjustment period is set as the transmission prohibition period. It is a control device that outputs the first cycle data for each control cycle.
An acquisition unit that acquires the first period data together with the transmission start time of the first period data, and
The reference time for the N + 1 cycle is calculated by adding a time interval corresponding to the control cycle to the transmission start time of the first cycle data to be transmitted in the control cycle of the N cycle, where N is a natural number of 0 or more. Calculation unit and
The transmission prohibition period generated by using the difference between the transmission start time of the first cycle data to be transmitted in the control cycle of the Nth cycle and the reference time of the Nth cycle is set before the reference time of the N + 1th cycle and The setting part to be set on at least one of the back and
A transmission unit that starts transmission of second period data having a lower priority than the first period data during a period other than the transmission prohibition period set by the setting unit.
A first generation unit that generates a basic period, which is a period required for transmission of the second period data, from the amount of data of the second period data.
A second generation unit that generates an adjustment period that is the difference between the transmission start time of the first cycle data to be transmitted in the control cycle of the Nth cycle and the reference time of the Nth cycle.
Equipped with
The transmission prohibition period set by the setting unit includes the total period of the basic period and the adjustment period.
When the transmission start time of the first cycle data to be transmitted in the control cycle of the Nth cycle is earlier than the reference time of the Nth cycle, the setting unit may use the reference time of the N + 1th cycle as the end point. The control is characterized in that the period including the basic period is set as the transmission prohibition period, and the period including the adjustment period is set as the transmission prohibition period so that the reference time of the N + 1 cycle becomes the starting point. Device. It is a control device that outputs the first cycle data for each control cycle.
An acquisition unit that acquires the first period data together with the transmission start time of the first period data, and
The reference time for the N + 1 cycle is calculated by adding a time interval corresponding to the control cycle to the transmission start time of the first cycle data to be transmitted in the control cycle of the N cycle, where N is a natural number of 0 or more. Calculation unit and
The transmission prohibition period generated by using the difference between the transmission start time of the first cycle data to be transmitted in the control cycle of the Nth cycle and the reference time of the Nth cycle is set before the reference time of the N + 1th cycle and The setting part to be set on at least one of the back and
A transmission unit that starts transmission of second period data having a lower priority than the first period data during a period other than the transmission prohibition period set by the setting unit.
A first generation unit that generates a basic period, which is a period required for transmission of the second period data, from the amount of data of the second period data.
A second generation unit that generates an adjustment period that is the difference between the transmission start time of the first cycle data to be transmitted in the control cycle of the Nth cycle and the reference time of the Nth cycle.
Equipped with
The transmission prohibition period set by the setting unit includes the total period of the basic period and the adjustment period.
When the transmission start time of the first cycle data to be transmitted in the control cycle of the Nth cycle is later than the reference time of the Nth cycle, the setting unit sets the reference time of the N + 1th cycle as the end point. A period including the total period of the basic period and the adjustment period is set as the transmission prohibition period.
When the transmission start time of the first cycle data to be transmitted in the control cycle of the Nth cycle is earlier than the reference time of the Nth cycle, the period including the basic period so that the reference time of the N + 1th cycle becomes the end point. Is set as the transmission prohibition period, and the period including the adjustment period is set as the transmission prohibition period so that the reference time in the N + 1 cycle becomes the starting point. If the transmission unit does not continuously transmit the second cycle data over a predetermined number of control cycles, the second cycle data is forcibly transmitted to the transmission unit even during the transmission prohibition period. The control device according to any one of claims 1 to 3 , further comprising an instruction unit for starting the above. Unless the transmitting unit continuously transmits the second cycle data over a predetermined number of times of the control cycle, the transmitting unit does not continuously transmit the second cycle data over the predetermined number of times of the control cycle. The control device according to any one of claims 1 to 4 , further comprising a notification unit for notifying the outside. It is a control method of a control device that outputs the first cycle data for each control cycle.
An acquisition step of acquiring the first period data together with the transmission start time of the first period data, and
The reference time for the N + 1 cycle is calculated by adding a time interval corresponding to the control cycle to the transmission start time of the first cycle data to be transmitted in the control cycle of the N cycle, where N is a natural number of 0 or more. Calculation steps to be performed and
The transmission prohibition period generated by using the difference between the transmission start time of the first cycle data to be transmitted in the control cycle of the Nth cycle and the reference time of the Nth cycle is set before the reference time of the N + 1th cycle and Setting steps to set at least one of the back and
A transmission step for starting transmission of second cycle data having a lower priority than the first cycle data during a period other than the transmission prohibition period set in the setting step, and a transmission step.
A first generation step of generating a basic period, which is a period required for transmission of the second period data, from the amount of data of the second period data, and
A second generation step that generates an adjustment period that is the difference between the transmission start time of the first cycle data to be transmitted in the control cycle of the Nth cycle and the reference time of the Nth cycle.
Including
The transmission prohibition period set in the setting step includes the total period of the basic period and the adjustment period.
In the setting step, when the transmission start time of the first cycle data to be transmitted in the control cycle of the Nth cycle is later than the reference time of the Nth cycle, the reference time of the N + 1th cycle becomes the end point. , The period including the total period of the basic period and the adjustment period is set as the transmission prohibition period.
A control method characterized by that. It is a control method of a control device that outputs the first cycle data for each control cycle.
An acquisition step of acquiring the first period data together with the transmission start time of the first period data, and
The reference time for the N + 1 cycle is calculated by adding a time interval corresponding to the control cycle to the transmission start time of the first cycle data to be transmitted in the control cycle of the N cycle, where N is a natural number of 0 or more. Calculation steps to be performed and
The transmission prohibition period generated by using the difference between the transmission start time of the first cycle data to be transmitted in the control cycle of the Nth cycle and the reference time of the Nth cycle is set before the reference time of the N + 1th cycle and Setting steps to set at least one of the back and
A transmission step for starting transmission of second cycle data having a lower priority than the first cycle data during a period other than the transmission prohibition period set in the setting step, and a transmission step.
A first generation step of generating a basic period, which is a period required for transmission of the second period data, from the amount of data of the second period data,
A second generation step that generates an adjustment period that is the difference between the transmission start time of the first cycle data to be transmitted in the control cycle of the Nth cycle and the reference time of the Nth cycle.
Including
The transmission prohibition period set in the setting step includes the total period of the basic period and the adjustment period.
In the setting step, when the transmission start time of the first cycle data to be transmitted in the control cycle of the Nth cycle is earlier than the reference time of the Nth cycle, the reference time of the N + 1th cycle becomes the end point. The period including the basic period is set as the transmission prohibition period, and the period including the adjustment period is set as the transmission prohibition period so that the reference time of the N + 1 cycle becomes the starting point.
A control method characterized by that.

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