JP2000276408A - Serial communication equipment, detection of abnormality for this equipment, and recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a serial communication equipment which easily detects the abnormality of a slave station and performs equipment maintenance in a shorter time. SOLUTION: If a transmission line of a serial transfer clock connected in parallel to slave stations 22 to 33 is disconnected or short-circuited in the position of the slave station in a certain part or a transmission line of shift transfer connected in series to each slave station is disconnected or short-circuited in the position of the slave station in a certain part, return information contents from all slave stations existing below the position of this slave station are not practically transferred to a master station 21, and identifier information contents are all one or all 0 from a certain position. Consequently, it is discriminated in the master station (CPU) 21 whether information contents are all one or all 0 or not to decide disconnection or shirt-circuit of transmission lines.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a serial communication device, a method for detecting an abnormality thereof, and a recording medium.
The present invention relates to a serial communication device for exchanging information between a master station in an apparatus and a plurality of slave stations scattered in the apparatus, a method for detecting an abnormality thereof, and a recording medium.

[0002]

2. Description of the Related Art Conventionally, a serial communication device in a device has a main device for serial communication called a master station of a central processing unit of the device and a slave station having a plurality of electric units scattered in the device. Exchanges information with a serial communication sub-device called
It is used in many devices for the purpose of suppressing the cost of the device and the ease of assembling the device.

[0003] Basically, in an information exchange configuration in a serial communication device, serial communication is performed in response to an information exchange request generated by a master station included in a central processing unit (CPU) of the device. In addition, the information exchange request from the slave station updates the information from the slave station by executing the serial communication as described above by the master station that has received the communication request signal, whereby both information exchanges are performed. .

[0004] This information exchange is performed by the master station and the slave station on a one-to-one basis. Transfer information originating from the master station is transferred to a specific slave station, and transfer information returned from the slave station is transmitted. It is necessary that the master station and the slave station recognize each other that the information is from the slave station that can be identified by the master station. For this reason, many conventional serial communication devices are configured to transfer the transfer information with identifier information designating a slave station attached thereto. This method is established after limiting the maximum number of slave stations that can be connected to the transmission path. A communication protocol and a data processing means thereof, in which the number of information bits transferred to one slave station and the number of identifier information bits are a set, and the data length configuration of the number of slave stations that can exist on the transmission path is a basic condition for transfer. Is designed. Therefore, in a serial communication device that employs such a method, a communication protocol and its data processing means are designed in consideration of a large number of slave stations in order to determine the number of slave stations that can be connected in advance. This was disadvantageous in view of cost. Further, even when the design is changed in accordance with the configuration of the number of slave stations of the entire device to be used, the basic configuration of the data length to be transferred is changed, so that at least the data processing means is redesigned. .

Therefore, in recent years, while the number of information bits transferred to one slave station and the number of identifier information bits are fixed,
A serial communication device comprising a communication protocol and a data processing means for connecting a semi-infinite number of slave stations has appeared. Thereby, regardless of the configuration of the number of slave stations of the entire device using the serial communication device,
The same serial communication device can be used with the optimum number of slave stations, and it is possible to easily cope with a design change in the middle. Naturally, the cost of the serial communication device can be reduced to the number of slave stations required by the entire device, so that the cost is reduced as compared with the conventional serial communication device. Hereinafter, a configuration of a serial communication device that can connect a semi-infinite number of slave stations while keeping the number of transfer information bits and the number of identifier information bits fixed will be described.

First, a basic configuration of serial communication will be described.

In a conventional serial communication apparatus, a master station creates a data length of transfer information, and transmits the data length of transfer information to a shift register circuit (constituting bit number of 4 bits) of each slave station together with a transfer clock. In the configuration in which the output information is shifted and transferred, by loading the shift register circuit with the slave parallel input information which is returned to the master in advance before the master performs the shift transfer, the shift transfer performed by the master is performed. This enables information exchange between the master station and each slave station.
Each slave station is configured to execute an operation specified by the count value of the phase control counter circuit that the slave station has, and the master station operates the count value of the phase control counter to shift the shift register of the slave station. Controls the operation of circuits, etc. The master station includes a master station phase control counter to control the phase control counter of each slave station, and operates in the same manner as the phase control counter circuit of the slave station.
The operation status of the slave station can be grasped by the count value, and the operation of each slave station in the transmission path is executed to realize the serial communication.

On the other hand, the master station recognizes a semi-infinite number of slave stations that can be connected to the transmission path with a fixed number of identifier information bits and performs one-to-one information exchange by performing a plurality of serial communication operations. Are configured to be executed separately.

One is communication for the purpose of recognizing a slave station existing on a transmission line, and is referred to as "initialization communication" in the following description. In this initialization communication, the identifier information of each slave station is downloaded, and the order of the slave stations in the transmission path is recognized. The other is communication in which a shift transfer data length is created and transferred in accordance with the slave station arrangement order recognized in the initialization communication, and is referred to as "normal communication" in the following description. In this normal communication, one-to-one information exchange is performed with each slave station. In other words, since the order of the slave stations connected to the current transmission path is unchanged after re-recognition by the initialization communication, the return information data length from each slave station according to the slave station order is shifted and returned. Therefore, information exchange can be easily realized.

Here, a basic idea for recognizing the number of slave stations which can be expressed by a fixed number of identifier information bits will be described. Note that, here, the description is made on the assumption that the fixed number of identifier information bits is 4 bits, but this is an assumption for easy understanding of the description, and is not particularly limited.

First, as a premise, slave stations are classified into two types based on the configuration of the equipment in which the serial communication device is used. On the other hand, a slave station used for a unit necessary for the operation of the device is called a main unit, and identifier information is assigned by a fixed value code. On the other hand, a slave station that is used for an option that is not necessarily required for the operation of the device and is a so-called extension unit is referred to as an option unit, and identifier information is assigned to each option unit as a code value of an assigned value. That is, the identifier information is all zero (0000B) and all one (111
1B) and fixed values for the main unit (here, (11
01B)) and 1 (0001B)
The code values are assigned to the option units in order from. In other words, considering the arrangement order of the transmission lines only by the main unit configuration, the arrangement order is an invariable arrangement order because of the required units. That is, since the set slave station arrangement for the main unit is invariable when the main unit is arranged alone, the memory map may be performed in accordance with the order of arrangement on the transmission path.

Next, a description will be given of a connectable optional unit slave station based on the main unit slave order. In the case of an optional unit slave station, it is unknown whether or not it is always connected to the transmission path, so the identifier information is assigned in order, especially when using a main unit whose arrangement order is determined in the main unit array. A plurality of option units existing between the main units are regarded as one group, and in the same group, unique identifier information is sequentially allocated to 1, 2, 3,... These groups are respectively configured between different main body units. That is, the identifier information to which the option unit is assigned may overlap between different groups.

According to the above concept, even if the number of slave stations is half-infinite, each slave station can be identified by 4-bit identifier information. In other words, up to thirteen optional units are allocated between the first and second main units with non-overlapping code values.

Thus, when there are five main units, for example, 4 × 13 = 52 optional units can be identified one-to-one. Conversely, if the number of optional units required for the main unit including the dummy is facilitated, a semi-infinite number of slave stations can be recognized as long as the electrical transmission capability of the transmission path is allowed.

The overall operation in the case where the serial communication device capable of connecting a semi-infinite number of slave stations described above actually executes communication will be described.

First, in a device in which a serial communication device is used as a master station, the total number of slave stations connectable to the serial communication transmission line and their arrangement order are set in advance. It is mapped to the memory for storage. Then, the master station performs serial communication by initialization communication, siphons identifier information according to the sequence of slave stations connected to the actual transmission path, and sets the presence / absence of slave stations registered in the memory. . This allows
The mapped slave station order is set to the slave station order existing in the current transmission path, and the memory map is reset. By this operation, the master station can grasp the arrangement order of the slave stations existing in the transmission path, and in the subsequent processing,
The data length of the shift transfer is constructed and output in accordance with the slave station order shown by the reset memory map, and the data length of the input shift transfer is stored in the memory in accordance with the slave station order shown by the reset memory map. And serial communication can be executed. The serial communication at this time is referred to as normal communication as described above,
Information is exchanged between the master station and each slave station.

As described above, in the execution of the normal communication which occupies most of the serial communication, the data of the number of information bits corresponding to the predetermined number of slave stations is prepared, and after the return data is loaded to each slave station, the shift operation is executed. Then, information can be transferred from the master station to each slave station or from each slave station to the master station, so that the communication time is minimized, signal processing is simplified, and the circuit configuration of the slave station is reduced. However, the cost is further reduced. On the other hand, in the normal communication, after making a round of the shift transfer for exchanging information, the second-order shift transfer is performed again with the same contents of information, and a single serial communication operation is performed. Is performed, and by comparing the first information content with the second information content, the accuracy of the information content can be improved with a simple configuration, and erroneous transmission of information can be prevented.

Hereinafter, the specific contents of serial communication by the conventional serial communication device will be described with reference to FIGS.

First, the operation of the conventional slave station will be described with reference to FIG. FIG. 6 is a block diagram showing a conventional slave station configuration.

In FIG. 1, reference numeral 1 denotes an input selector circuit. The input selector circuit 1 selects whether information returned from the slave station to the master station is identifier information which is parallel input information. 2 is an input latch circuit. The input latch circuit 2
It is connected to the output side of the input selector circuit 1 and latches the information selected by the input selector circuit 1 over the execution period of one serial communication. The output side of the input latch circuit 2 is connected to a first exclusive OR circuit (hereinafter, referred to as a "first EXOR circuit") 3 and a shift register circuit 4 for a slave station to execute shift transfer.

The first EXOR circuit 3 has an input latch circuit 2
, And the signal output from the input latch circuit 2 are input. The input and output of the input latch circuit 2 are compared bit by bit, and the comparison results are combined into one by a multi-input gate. The output is turned on when either the input to the input latch circuit 2 or the output from the input latch circuit changes even one bit.

The output side of the shift register circuit 4 is connected to a twice-read latch circuit 5 and a second exclusive OR circuit (hereinafter, referred to as a "second EXOR circuit") 6. The twice-read latch circuit 5 latches and holds the information of the first cycle of the shift transfer, and its output side is the second EX.
It is connected to an OR circuit 6 and an output latch circuit 7. The second EXOR circuit 6 compares the information content in the second shift transfer and the information content latched and held in the twice-read latch circuit 5 for each bit, and combines the comparison result into one signal by a multi-input gate. Output
Either the information content in the second shift transfer or the information content latched and held in the twice-read latch circuit 5 is 1
Turns on when a bit changes.

The output latch circuit 7 includes a second EXOR circuit 6
Only when all the bits match as a result of the comparison, the latch holding operation is executed, and the latched signal is output to the outside as a parallel output of the slave station.

The first decoding circuit 9 classifies and outputs a 2-bit slave station instruction coded signal designated by the master station into a soft reset signal, a forced reset signal, and a count instruction signal.

The gate circuit 8 is connected to the input selector circuit 1 and sends a selection instruction signal composed of a soft reset signal sent from the first decode circuit 9 and a transfer clock to the input selector circuit 1. Output, the input selector circuit 1 indicates the type of information to be selected.

The clock number counter circuit 10 is connected to the second decode circuit 12, counts the number of input transfer clocks, and outputs a timing pulse to the second decode circuit 12 for each predetermined value.

The phase control counter circuit 11 is connected to the first decode circuit, and uses the transfer clock as a count source to perform operations such as a count operation and a count stop hold in accordance with the count instruction signal classified by the first decode circuit 9. I do. Note that the master station also has master station phase control counter means operated in the same manner as the phase control counter circuit 11 and controls shift transfer.

The second decoding circuit 12 uses the Q output as the count result of the phase control counter circuit 11 as an input source, outputs an operation output instruction to each circuit based on the control phase timing, and outputs an input from each circuit. The signal is output to the main station as a return phase signal based on the control phase timing.

The operation of the shift register circuit 4 for executing the shift transfer is basically controlled by operating the count value of the phase control counter circuit 11 by the slave station coded signal instructed by the master station. You. Specifically, the count value of the phase control counter circuit 11 (hereinafter referred to as “control count value”) is controlled by timing control for executing a counter operation using a transfer clock as a clock source by a slave station coded signal generated by the master station. Operation control such as count-up, stop, and control count value reset is performed, and the second decode circuit 12 directly outputs a timing instruction signal to a circuit that executes each slave station operation.

Here, a flow of a conventional slave operation will be briefly described focusing on shift transfer.

When a soft reset is instructed by the slave station instruction coded signal, the control count value becomes "00H". During the soft reset, the input selector circuit 1 uses the fact that the control count value does not change even when the transfer clock is received.
Is selected. The gate circuit 8 is configured to switch the selection instruction signal of the input selector circuit 1 depending on whether a transfer clock is received during a soft reset. Thereby, in the input selector circuit 1, either one of the parallel input and the identifier input is selected,
The selected information is transmitted to the input latch circuit 2.

Thereafter, when the soft reset is released and a new transfer clock is received, the input information is latched and held in the input latch circuit 2, and the information is accessed to the shift-in parallel input of the shift register circuit 4. . On the other hand, the latch input and output of the input latch circuit 2 are the first E
The XOR circuit 3 compares the bits on a bit-by-bit basis.
Sent to This signal is a source of a communication request signal issued from the slave station, and is transmitted from the return phase signal to the master station at a predetermined control count value (here, it is assumed to be valid at the timing of 0EH). Is what is done.

When the master station subsequently instructs the control count value to be 01H, the output information of the input latch circuit 2 is shift-loaded into the shift register circuit 4, and the shift transfer operation is started upon receiving the transfer clock. From this time, the master station issues transfer data and a transfer clock of the number of pits corresponding to the number of slave stations in the transmission path grasped by initialization communication to be described later, and performs control count at a desired timing by a slave station instruction coded signal. While manipulating the value, instruction control is performed so that the control count value becomes 06H at the shift end timing at which the shift transfer is completed. When the control count value reaches 06H, the slave station determines that the first round of the shift operation has been completed, and reads the shift data of the shift register circuit 4 from the second decode circuit 12 to the twice-read latch circuit 5. A latch signal (latch pulse) is output to hold the latch. At this time, the information of the input latch circuit 2 latched and held at “00H” is accessible to the shift register circuit 4. Note that the information content latched and held in the input latch circuit 2 is not updated except when the control count value becomes "00H", so that the same information content is held when the control count value is 06H.

Then, the control counter value is set to "0" by the master station.
7H ", and the second round of the shift transfer is started. In the shift register circuit 4, the shift data is loaded again at "07H" and the shift operation is started. On the other hand, in the master station, the same information content as that in the first shift transfer is similarly loaded, and transfer data and a transfer clock having the number of bits corresponding to the number of slave stations in the transmission path are issued.

When the same operation as in the first cycle is performed and the control count value becomes "0CH" in accordance with the shift transfer end timing, it is determined that the second-order shift transfer has been completed, and the second EXOR circuit 6 In the above, the output of the twice-read latch circuit 5 holding the data of the first cycle and the output of the shift register circuit 4 having the second-order data are compared bit by bit. As a result, when all the contents match for each bit, the output of the second EXOR circuit 6 is turned off,
If any one bit does not match, the output is turned on.

When the control count value becomes "0DH", the second decode circuit 12 outputs a latch holding pulse to the output latch circuit 7 when the read results match twice. If the read results do not match, no latch holding pulse is output to the output latch circuit 7, and the return phase signal is turned on.

If the return phase signal is turned on when the control count value is "0DH", the master station determines that the shift transfer has failed due to a communication error and recognizes it as a communication error. In this case, as described later, the control count value is returned to “00H” by the soft reset, and the serial communication is executed again as a retry of the serial communication. In addition,
If an error occurs even after the retry communication is performed a predetermined number of times, the operation of the entire device is stopped as a serial communication failure, and the process is terminated in a state where a predetermined state such as a serviceman call is maintained. On the other hand, if the shift transfer is successful at “0DH”, the transfer information to the slave station is output as the slave station parallel output, and the shift transfer operation is terminated.

As a result, in the master station, the input shift transfer data from the slave station is read and compared twice, and when all the data match, the information content is updated to a predetermined memory. Also,
If the result of the double reading and comparison indicates that even one bit does not match, retry communication is executed after a soft reset.
If the master station determines that the shift transfer was successful,
The control count value is operated so as to be "0EH". This time, the state of the return phase signal is detected to determine the presence / absence of a slave communication request signal from each slave station. This "0E
The state of "H" is maintained until a communication request occurs in at least one slave station or master station. If there is a communication request, the control counter value is immediately set to "00H" and serial communication is performed again. Is executed.

That is, in the master station, the return phase signal at the time of “0DH” is used as a transfer error determination,
The return phase signal at the time of "EH" is used as a slave station communication request determination. As described above, the return phase signal output is configured to be read by the master station while distinguishing its meaning according to the control count value. Therefore, the master station is configured as necessary so that it can make determinations with various contents according to the control count value, and by devising the operation timing of the control count value, it is possible to categorize return signals indicating various meanings. it can.

On the other hand, in the slave station, when the control count value becomes "0EH", the second decoding circuit 12
The output state of the EXOR circuit 3 is output as a return phase signal. While the control count value is “0EH”, the presence / absence of a slave communication request is transmitted, and the latch information contents of the input latch circuit 2 in which the slave parallel input information shifted and transferred as described above is latched and held, As soon as even one bit of the contents of the slave station parallel input information currently accessed to the input terminal of the input latch circuit 2 is updated, it is output as a slave station communication request for requesting the master station to exchange information. With this signal, the same operation as the bidirectional serial communication configuration can be provided even in the case of the unidirectional serial communication configuration originally from the master station.

Next, a specific example of the conventional control of the main station will be briefly described with reference to FIGS.

FIG. 7 is a transmission path diagram when all slave stations that can be connected to the equipment using the conventional serial communication device are connected. The master station control is performed by the slave stations allocated in the order shown in FIG. The control is executed based on the arrangement order. Note that the slave station arrangement order of the basic transmission path is determined according to the equipment to be used.For example, if the slave station arrangement order is changed due to a specification change or the like, the basic station order is changed according to the content of the change. May be changed.

The transmission path diagrams of the serial communication apparatus shown in FIGS. 7 and 8 form a ring-shaped transmission path composed of the slave stations 22 to 33 starting from the master station 21.

FIG. 7 shows an arrangement order of all slave stations connectable to a transmission line, which is defined in advance in a serial communication device in a certain device. The slave station arrangement order is developed as a basic memory map set in the master station, and is mapped at the time of memory initialization setting processing operation of the whole CPU, which is executed at the time of resetting the CPU immediately after turning on the power. Is what is done. The expansion of the memory map shown in the memory map diagram (FIG. 9) described later shows the order of the slave stations in the basic transmission line in the conventional example. In other words, the serial communication device maps the data on the basis of the sequence of the slave stations on the transmission line when all the slave stations determined in advance by the device are connected, and then executes the initialization communication to perform the memory map. Is reset. Then, when the normal communication is executed, the slave station arrangement order of the current transmission line is grasped, and the data length of only the information content constituted by the slave station arrangement order of the current transmission line is shifted and the information exchange is executed. You do it.

FIG. 8 is a transmission path diagram showing an example of the order in which slave stations are arranged in a transmission line in the serial communication apparatus at the time when a certain device actually operates. In the figure,
The order of the slave stations in the transmission path is different from the order of the slave stations in the basic transmission path (FIG. 7) by the electric units (switchback unit, high-voltage (blue) unit, high-voltage (yellow) in the example of FIG. ) Unit, envelope unit,
And five electric units of the double-sided control unit) are used in a state where they are omitted as necessary. The electric unit referred to as an option here is not limited to an option installed by a user, but also includes an option installed at the time of assembly in a factory, for example.

FIG. 9 is a conceptual diagram of a memory map used when the serial communication device performs information exchange.
The transition of the map figure of the storage memory which only the main station has is shown. In this figure, the slave-station parallel output information shown in FIG. 9A and the slave-station parallel input information shown in FIG. 9B are obtained by mapping the slave station arrangement order in the above-described basic transmission path. On the other hand, the slave station parallel output information shown in FIG. 9C and the slave station parallel input information shown in FIG. 9D map the slave station order on the current transmission line by initialization communication described later, and The map has been reset. That is, by performing normal communication based on the reset sequence of the slave stations shown in FIGS. 9C and 9D, information exchange with each slave station is performed, and the data content is updated. On the other hand, a device using such a conventional serial communication device executes device control by reading and writing the memory map. In FIG. 9, bits indicated by “X” and “Z” indicate information content updated with the execution of normal communication.

FIG. 10 is a flowchart showing a serial communication task when executing serial communication in a conventional serial communication device. FIG. 11 is a flowchart showing an initialization communication procedure when executing conventional serial communication. 12 and 13 are flowcharts showing a normal communication procedure when executing conventional serial communication.
The initialization communication and the normal communication shown in FIGS. 11, 12 and 13 are started in the serial communication task shown in FIG. In the case of the normal communication, the shift transfer for executing the serial communication operation is performed twice, and the information contents of the first and second rounds are compared (that is, the above-described double transmission and double reading are performed). However, in the case of the initialization communication, the communication operation is controlled to be forcibly terminated by performing a soft reset at a stage where the shift transfer for executing the serial communication operation has been performed once. I have. This is because the reset of the memory map is finished as soon as possible and the system can be shifted to the normal communication. With this process, the entire device can be started up as quickly as possible. Therefore, in the case of initialization communication, resetting of the memory map by shift transfer is rounded up in one round of shift transfer, and the processing shifts to the next normal communication as one serial communication.

When the power is turned on and the CPU is reset, the CP
By executing the initialization setting processing of the memory of the U, the arrangement order of all the slave stations connectable to the basic transmission path is mapped in the memory part of the master station.
The control program of the device by the U operation is started, and at the same time, the serial communication task which is the main station shown in FIG. 10 is also started.

Before executing the normal communication for exchanging information with each slave station, the master station first performs initialization communication for determining the order of arrangement of slave stations existing in the current transmission path. At this time, the memory state of the master station is as shown in FIGS.
The memory map shown in FIG.

When the serial communication task, which is the master station, is started, it is determined whether or not the retry counter value is equal to or greater than a predetermined value (step S101). Since the retry counter value is initially zero, it is next determined whether or not the memory map reset flag indicating “1” indicating that the memory map has been reset is “1” ( Step S102). If it is determined in step S102 that the memory map reset flag is “0”, the memory map is reset (step S103). Step S10
The memory map resetting of No. 3 is performed according to the flowchart shown in FIG.

That is, first, the communication software reset is turned on, and the idle transfer (one clock) of the transfer clock is performed to make the input selector circuit 1 of the slave station shown in FIG. 5 access the identifier information of the slave station (FIG. 5). Step S1
21). When the idle transfer of the transfer clock is not performed, the input selector circuit 1 of the slave station may be configured to access the information content of the slave station. Then, a memory pointer specified for resetting the memory map and a communication error flag for registering an error in the communication result are initialized to “00H” (step S1).
22) The memory pointer is incremented by "1" (step S123), and is indicated by a value obtained by adding the head value address (MTO) of the memory map of the slave station parallel output information in which the slave array order is registered in advance and the memory pointer value. It is determined whether or not the memory address to be read is equal to the final address (MTE) of the memory map of the slave parallel output information in which the slave array order is registered in advance (step S1).
24). If the two values are equal, it means that the scanning of the memory map has been completed.

If it is determined in step S124 that the value of the start value address MTO is not equal to the value of the end value address MTE, preparation for output of transfer data to be shifted is performed (step S125). In this initialization communication, all-zero transfer data is shift-transferred. However, the present invention is not particularly limited to this, and data having contents other than all-zero may be shift-transferred depending on the use of the serial communication device. .

Then, 4-bit shift transfer is executed in accordance with the configuration of the slave station circuit. That is, one-bit shift transfer is performed, the transfer clock is transferred by one clock, and the clock number counter is incremented by "1" (step S126), and one-bit shift transfer input is performed (step S127). It is determined whether or not the 4-bit shift transfer has been completed (step S12).
8).

By repeating the processing procedures of steps S126 to S128, shift transfer of 4 bits is executed. When the 4-bit shift transfer is completed in step S128, the identifier information from the first slave station returned to the master station by the shift transfer is processed.
Here, the contents of the memory address indicated by the sum of the start address MTO of the memory map, which is the slave parallel output information of the basic memory map, and the memory pointer value are picked up, and the contents of the upper 4 bits are picked up. It is acquired (step S129), and is compared with the 4-bit identifier information determined to be input completed in step S128, and it is determined whether or not both match (step S130).

If it is determined in step S130 that they match, it is determined that there is a slave station of the identifier information registered in the slave station parallel output information of the basic memory map, so that the above-described steps S123 to S130 are performed. Is executed again, and the presence or absence of the slave station is determined based on the identifier information by the next shift transfer.

If it is determined in step S130 that they do not match, it is determined that there is no slave station of the identifier information registered in the slave parallel output information of the basic memory map. The contents of the identifier information indicated by 4 bits are cleared to all zeros (00H), which means that there is no slave station, and re-registration is performed (step S).
131). Further, by incrementing the memory pointer by “1”, the slave station of the registered identifier information located next to the slave parallel output information of the basic memory map is designated (step S132), and the above-described step S1 is performed.
Returning to 29, the existence of the slave station is determined again.

That is, the registration is deleted by setting the contents of the memory area of the non-existing slave station to “00H”, and the existing slave memory area is left as it is by leaving the already registered identifier information as it is. The array order is reset.

When the above operation is repeated and the slave station arrangement order of the basic memory map is reset, step S12 is performed.
Since the value obtained by adding the value of the memory pointer to the value of the start value address MTO in the determination of 4 reaches the value of the end value address MTE, the total number of transfer clocks actually output in the shift transfer in execution of the initialization communication is counted. By dividing the value of the clock number counter of the master station by 4 bits, which is the number of bits forming one slave station, the total number of slave stations present on the current transmission path is calculated. This total number of slave stations and the reset memory map It is determined whether the total number of the slave stations determined to exist above matches (step S133).

If it is determined in step S133 that the calculated total number of slave stations coincides with the reset total number of slave stations on the memory map, the sequence of the slave stations is normally reset by the initialization communication. The flag is set to "1" and the communication software is reset (step S134).
The initialization communication is terminated. On the other hand, if they do not match, the reset has not been performed normally, so the retry counter is incremented by "1" and the communication software is reset while the reset flag remains "0" (step S13).
5) Once this procedure is completed.

Step S134 or step S135
When the initialization communication is completed by the
The serial communication task of 103 is temporarily ended.

Thereafter, the serial communication task is started again, and as described above, the retry counter value is less than the predetermined value and the step S102
If the memory map reset flag is “0” in the determination of, the initialization communication is retried again in step S103. If retry of initialization communication is repeated,
In step 135 of FIG. 11, the retry counter value reaches a predetermined value, and in step S101 of FIG. 10, it is determined that the value is equal to or larger than the predetermined value. In this case, it is determined that communication is not possible, and communication failure processing is executed (step S104).
This communication failure routine is to stop the operation of the entire device as a device failure, and is required to respond to a service person.

The above is the master station control of the initialization communication. Here, with reference to FIGS. 8 and 9 again, a specific initialization communication operation in the case of the conventional example will be briefly described from the operation of the entire serial communication device. The reset of the memory map by the initialization serial communication is performed based on the basic memory map of the slave station arrangement order shown in FIGS. 9A and 9B. First, the master station initializes the slave station parallel output state by shifting and transferring the information content of the lower bit string of the slave station parallel output information of the memory map in the base station arrangement order to each slave station. In the case of the serial communication device of this conventional example, all zeros are set to initialize the slave station parallel output state, but the present invention is not particularly limited to this, and the contents of the initialization information are basic. This may be set in advance when the memory map in the slave station arrangement order is created. Then, in the master station, as described above, a soft reset is issued to each slave station, and the input content of the slave station identifier is loaded into the shift register by operating the transfer clock. Thereafter, slave parallel output information for initializing the slave parallel output state is shifted and transferred. As a result, the slave station parallel output information contents to be initialized are output to the parallel output terminals to the slave stations, and the identifier information contents are sequentially returned to the master station in the slave station arrangement order of the transmission path. In the master station, this identifier information content is divided every 4 bits, compared with the order of the identifier information content registered in the memory map of the base slave array order, and the slave array order of the current transmission line is reset. You.

Here, the rules for the identifier information will be briefly described. The electric unit required for the device configuration is called a main unit, and a fixed value is assigned as identifier information. In addition, even if it is not a device configuration, an electrical unit that performs a device operation is called an option unit, and values are sequentially assigned as identifier information. However, in the case of an optional unit, it is not simply assigned in order from “1”. In other words, since the main unit always exists in the apparatus, it is only necessary to confirm that the main unit is located at the position of the transmission path set in advance, so that the identifier information can be set as a fixed value. On the other hand, since the option units always exist between the main units whose position order has already been determined, the numbers are sequentially assigned based on one main unit. Therefore, the identifier information of the option unit is identical between the main units and there is no duplicate identification information information, but it is allowed to be duplicated between the main units in different sets.
The identification determination is also possible. As shown in FIG.
The allocation of the identifier information is indicated by the upper 4 bits of the slave station parallel output information.

From the definition of the identifier information according to the above agreement,
The resetting of the memory map in the case of the transmission path shown in FIG. 8 will be described. Note that this memory setting is performed in the same manner as a general CPU memory operation, and is not limited to this format.

First, the identifier information (main unit) of the checker 33 is shifted and transferred to the master station. Here, since it is a main unit, the reference counter value is incremented to “01H”. On the other hand, the memory pointer counter value is not incremented and remains at "00H". Then, scanning is started from the start position address of the basic memory map, and the address position where the identifier information content of the main unit located in the order indicated by the reference counter value is registered is determined from the basic memory map. (Here, since it is "01H", the checker 33 which is the main body unit located first is calculated), and the reference pointer address is set at the address position. Then, the upper 4 bits of the memory at the address indicated by the memory pointer counter value and the addition result are compared with the contents of the identifier information shifted and transferred. Here, the 0th memory content “checker” of the main unit located at the 1st position is compared with the transferred content of the identifier information of the checker 33, and the two match. If they match, it is determined that there is a corresponding slave station, and the upper 4 bits set in the basic memory map are left as they are. This indicates that a slave station exists.

Next, the sorter identifier information (optional unit) is shifted and transferred. In this case, since this is an optional unit, the reference counter value is not incremented and remains at "01H", and the memory pointer counter value is set to "01H" which is incremented. As a result, the first memory (the "sorter" is shown in the figure) behind the first main unit.
Is compared with the transferred sorter identifier information content. As a result of the comparison, the two match and the corresponding slave is processed. Next, the identifier information to be shifted is shown in FIG.
Is the high-pressure red (optional unit) identifier, but is not the main unit, so the memory pointer counter value is incremented to “02H”. On the other hand, the reference counter value remains “01H”. Therefore, the memory located at the first position after the main unit located at the first position (denoted as "switchback" in the figure) is compared with the transferred sorter identifier information content. As a result, the two do not match, so the upper 4 bits of the switchback memory, which is the memory located second after the main unit located first, are reset to all zeros, thereby indicating that there is no corresponding slave station. It is.

Next, the value of the memory pointer counter is incremented again to "03H" and compared with the contents located in the next memory map. In this example, in this case also, it is determined that there is no match, and until the match, the memory of the mismatch is set without the corresponding slave station. When the memory pointer counter value is “04H”, that is, when the memory unit is compared with the memory located at the fourth position from the main unit located at the first position, both values match. Accordingly, this memory is set as having a slave station. Next, as can be seen from FIG.
(The main unit) is shifted and transferred. When the identifier information of the main unit is received, first, the option unit registered between the main units, starting from the memory after the value indicated by the reference counter value and the memory pointer counter value, and the reference counter value is indicated by the incremented value Are all set without the corresponding slave station. In this example, the high pressure (yellow) (optional unit) corresponds. Then, based on the incremented reference counter value, resetting of the basic memory map is continued.

When the reference counter is incremented, the memory pointer counter value is cleared to "0".
0H ". Then, the above-described operation is performed on all of the basic memory maps, whereby FIG.
The memory is reset as shown in FIG. In other words, this memory operation is basically performed from what position of the main unit to what position of the optional unit,
And the contents of the memory are set.

The above is the control operation of the initialization communication.

Next, a description will be given of normal communication controlled by the master station which performs information exchange with each slave station after the initialization communication.

In FIG. 10, when the initialization communication is performed in step S103, "1" is set in the memory map reset flag, and as a result, the memory map
As shown in the upper four bits of the slave parallel output information in (c), the slave array order in the basic memory map is reset to the slave array order of the slaves existing on the current transmission path.
Normal communication is performed based on the state of the slave station arrangement order.

If it is determined in step S102 in FIG. 10 that the memory map reset flag is "1",
It is determined whether or not the retry flag is "1" (step S105), and it is determined whether or not there is retry communication. In the retry communication, as in the case of the initialization communication, when one serial communication fails, the retry counter is incremented, and when the serial communication is within a predetermined value, the retry communication is executed. This retry communication means configuration has two types of communication means of the conventional serial communication device, that is, initialization communication and normal communication do not proceed simultaneously.
The same components are used. That is, when an error occurs in the retry communication exceeding a predetermined value, both the initialization communication and the normal communication are processed in the communication failure processing routine.

On the other hand, when the retry communication is executed, when the initialization communication is performed, as described above, step S in FIG.
At 135, the process of the retry counter is performed, and the retry communication is executed while the reset flag is reset, because it is not set in FIG. In the case of the normal communication, the process of the retry counter is performed in step S110 after the execution of the normal communication, and the execution of the retry communication is determined by the process of step S105. In other words, the retry communication control for the initialization communication and the normal communication is controlled separately, but the flags and counters necessary for the error processing routine and processing are shared.

Returning to FIG. 10, when the resetting of the memory map is completed, it is determined whether the retry communication is to be performed by checking whether the retry flag is "1" (step S105). . If no retry communication is determined in step S105, the master station communication request flag is set to “1”.
(Step S106) or whether the communication request signal at the slave station is on (step S107).
Is determined. When the master station communication request flag is set to "1" or when the slave station communication request signal is turned on, it indicates that execution of normal communication is requested. After the initialization communication is completed, the control count value of the slave station phase control counter circuit 11 and the control count value of the master station phase control counting means are both set to “00H” by the communication software reset. It is determined to be off.
Accordingly, the master station resets the master station communication request flag immediately after finishing the initialization communication, and instructs execution of the normal communication in step S106. On the other hand, if the normal communication is performed even once, the control count value is “0EH”,
As described above, the standby state is set to wait for the execution instruction of the normal communication. The process shifts from step S107 to step S110, where a processing signal such as a failure is reset, the task is temporarily ended as it is, and the processing after step S105 is performed again, thereby performing standby detection.
Then, when receiving the execution instruction of the normal communication, step S1
At 08, the normal communication shown in FIGS. 12 and 13 is executed.

In FIG. 12, first, a communication software reset is executed to synchronize the execution of communication (step S1).
41). Further, the communication abnormality flag, the memory pointer, the phase control counter, and the clock number counter are reset to “00H” (step S142). Then, the memory pointer for the memory operation is incremented (step S143), and the control counter value is loaded from the master station phase control counter (step S14).
4) It is determined whether or not the control counter value is a predetermined value (step S145). Here, “00” when the slave input information to be shifted and transferred from the slave is selected.
The determination is made based on the binary value of "06H" when the "H" shift transfer is performed once. Furthermore, the value of the result of the double reading comparison after performing the shift transfer twice is set to “0DH”, and is used for determination in steps described later. On the other hand, the validity period of the slave station communication request signal is set to “0EH”. Here, although the timing determination is not particularly performed, the communication operation in the normal communication is terminated, and the communication is ready for the next communication. Is controlled to be “0EH”.

If it is determined in step S145 that the control count value is the predetermined value, it is determined whether or not the return phase signal is ON (step S146). It is determined that the phase timings are normally synchronized, and step S15
0 processing is performed.

On the other hand, if it is determined in step S145 that the control count value is not the predetermined value, it is determined whether or not the return transport signal is turned off (step S147). If there is, it is determined that the phase timing is normally synchronized, and the process of step S150 is performed.

If it is determined in step S146 that the return phase signal is off at the time of on-check,
If the return phase signal is ON at the time of the OFF check in the determination of 147, it is determined that the phase timing is out of synchronization. Therefore, "1" is set to the phase error bit of the communication abnormality flag (step S148), the communication software reset is turned on (step S149), and the normal communication is canceled.

If it is determined in step S146 or S147 that the return phase signal is normal, normal communication is started. First, it is determined whether or not the sum of the memory pointer value and the start value address MTO of the reset memory map indicated by the slave station parallel output information is equal to the final value address MTE of the memory map (step S).
150).

If the two values are not equal, the shift transfer has not been completed yet, and the upper 4 bits of the memory contents indicated by the sum value address of the memory pointer value and the top value address MTO of the memory map are obtained. (Step S151), and it is determined whether or not the value is “00H” (step S152). Here, if it is “00H”, there is no slave station registered by resetting, so the flow returns to step S143 again, the memory pointer value is incremented, and shift transfer in the next slave station in the memory map is started.

In the determination of step S152, "00"
If it is not "H", the lower 4 bits of the memory content are obtained (step S153), and one-bit shift is performed for shift transfer (step S154). That is, in step S154, the content of one bit is shifted out, the transfer clock is output one clock, and the clock number counter is incremented by "1". Further, it is determined whether the value of the clock number counter means of the master station is a predetermined value (step S155). If the value is the predetermined value, the control count values of the phase control counters of the master station and the slave stations are respectively determined. "1" is incremented (step S156). On the other hand, if it is determined in step S155 that the value of the clock number counter is not the predetermined value, the process of step S156 is skipped. Then, a 1-bit return signal by the shift transfer is input (step S157), and it is determined whether or not the shift transfer for 4 bits corresponding to one slave station is completed (step S158).

If it is determined in this determination that the 4-bit shift transfer has not been completed, the process of step S154 is performed again. When the 4-bit shift transfer is completed, the 4-bit data is stored in the slave station parallel input information in the memory map shown in FIG. 9D (step S1).
59). Specifically, the shift-transferred 4-bit data is stored in the lower 4 bits of the memory content indicated by the sum value address of the memory pointer value and the start value address MTI of the memory map of the slave station parallel input information. , The information content is updated. Then, in order to repeat the abnormal operation to execute the shift transfer of the slave station, the process of step S143 is executed again. Then, as described above, if it is determined in step S150 that the data scan of the slave station to be shifted and transferred has completed one cycle, the processing after the execution of the normal communication is performed.

That is, the control counter value of the phase control counter is set to "0DH" (step S160),
It is determined whether the return phase signal is on (step S161). In this determination, if the return phase signal is ON, it means that an error has occurred in the double reading comparison in any of the slave stations, so the double reading comparison error bit of the communication abnormality flag is set ( Step S1
62), a communication software reset for executing the retry communication is executed (step S163), and the procedure is thereafter terminated.

On the other hand, if it is determined in step S161 that the return phase signal has not been turned on, it means that no error has occurred in the read comparison twice in all the slave stations. When the control count value is "0E
H ”(step S164), the communication request signal from each slave station is set to be valid, and the procedure ends.

Returning to FIG. 10, step S108 (FIG. 12)
When the normal communication process of FIG. 13) ends, it is determined whether or not the communication abnormality flag is “00H”, that is, whether or not the communication has ended normally (step S109). In this determination, when the communication abnormality flag is “00H”,
“0” is set to the retry flag and “00H” is set to the retry counter at step S11.
0), this task is terminated. Thereby, the communication standby state is continued until it is determined in step S106 or step S107 that there is a communication request from the master station or the slave station, and communication is basically not performed unless there is a request. .

If it is not "00H", some abnormality has occurred, so that the communication abnormality flag is analyzed (step S111), and "1" is set to the retry flag to instruct retry communication. And the retry counter is incremented (step S11).
2) This task is completed.

Although not shown, the communication abnormality flag is composed of a plurality of flags corresponding to various abnormal states. When the flag indicating that the content of the abnormal state is light is set by execution of the communication error flag analysis routine (here, the content of the abnormal state is set in advance into a light category and a severe category, and In step S112, the retry counter value is incremented by "1", and an instruction to execute retry communication is issued. On the other hand, when the flag indicating that the content of the abnormal state is heavy is set, the retry counter value is classified in advance so as to be directly set to a predetermined value causing an error on the spot.
When the task is started again after the task is terminated after the increment processing is performed, the retry communication is not executed, and the steps S101 to S104 are immediately performed.
Is performed, and the communication operation and the operation of the device are stopped in the communication failure processing routine.

The above is the master station control of the normal communication. This normal communication is executed after resetting the arrangement order of the slave stations existing on the current transmission line by performing the initialization communication, and when the arrangement order of the slave stations existing in the reset transmission changes. In this case, the initialization communication must be performed immediately to reset the memory.

Although not shown in the drawing, the part that generates the master station communication request includes a master station communication request flag that determines that each slave station needs to update information in each control task. set. Therefore, the master station checks the master station communication request flag in step S106 for controlling the normal communication of the serial communication task, and determines whether or not the normal communication is to be performed.

As described above, the normal communication is executed by sequentially shifting and transferring the lower 4-bit information contents validated by the slave station parallel output information of the reset memory map, and sequentially transmitting the returned information contents by the slave station parallel output. Only the lower 4 bits of the input information need be stored. In other words, once the memory is reset, the master station can exchange information with each slave station by simple and easy control such as simply transferring the contents of the memory.
In addition, the time required for executing the normal communication can be shifted by only the number of data bits for exchanging information, so that the processing can be performed in a minimum time.

However, whatever the device,
If the wiring between the electric units is disconnected or short-circuited for some reason, the operation of the device is not established. Not surprisingly,
The same applies to the serial communication device in the above conventional example. As a practical matter, when the apparatus becomes abnormal due to disconnection or short circuit, maintenance called a serviceman call is performed.

In recent years, equipment maintenance is mainly performed by finding an abnormal unit and exchanging the unit, thereby shortening the time required for the maintenance and minimizing the cost as much as possible.

[0093]

However, although it is relatively easy to confirm the operation of the electric unit itself, the serial unit in the device constituted by the loop transmission line as described in the above-mentioned conventional example is used. In communication devices,
There has been a serious problem that finding an abnormal slave station often takes a very long time. That is, since the serial communication device is mainly a signal processed in time series such as a transmission line for shift transfer or a transmission line for serial transfer clock, it is very difficult to find an abnormal slave station. . Furthermore, in a serial communication device having a light transmission element using a light transmission element or a light receiving element as a transmission path, since the light is emitted in the infrared region, there is a problem in that it becomes more difficult to find.

The present invention has been made in order to solve the above problems, and a serial communication device capable of detecting an abnormality of a slave station more easily and performing device maintenance in a shorter time, and an abnormality detection device for the serial communication device. It is an object to provide a method and a recording medium.

[0095]

According to a first aspect of the present invention, there is provided a serial communication apparatus comprising a transmission line having one master station and a plurality of slave stations. Shifting the output information from the master station to the plurality of slave stations in synchronization with the serial transfer clock generated by the master station, and returning the slave information from the plurality of slave stations to the master station using the shift transfer. A serial communication device for performing serial communication for performing information exchange between the master station and the plurality of slave stations, wherein the master station uses the shift transfer to return a slave station to the master station. Return information content determining means for determining the content of the information,
A transmission path abnormality detecting means for detecting an abnormality of the transmission path for the shift transfer or the transmission path for the serial transfer clock based on the result of the determination by the return information content determining means.

According to a second aspect of the present invention, in the serial communication apparatus according to the first aspect, the master station performs a current communication before performing serial communication for exchanging information with the plurality of slave stations. Initialization communication means for performing initialization communication for recognizing a slave station arrangement order of slave stations connected to the transmission path, wherein the transmission path abnormality detection means performs the initialization information communication by the initialization communication means; Based on the determination result of the content determination unit, when it is determined that the content other than the content of the identifier information registered in advance is received, the abnormality of the transmission path for the shift transfer or the transmission path for the serial transfer clock is determined. It is configured to detect.

The serial communication device according to claim 3 is the serial communication device according to claim 1, wherein the master station performs a current communication before performing serial communication for exchanging information with the plurality of slave stations. Initialization communication means for performing initialization communication for recognizing a slave station arrangement order of slave stations connected to the transmission path, wherein the transmission path abnormality detection means performs the initialization information communication by the initialization communication means; When a predetermined identifier information content is determined to be received based on the determination result of the content determination means, an abnormality of the transmission path for the shift transfer or the transmission path for the serial transfer clock is detected. It is characterized by being performed.

A serial communication device according to a fourth aspect of the present invention is the serial communication device according to any one of the first to third aspects, wherein the serial communication device corresponds to the arrangement of the plurality of slave stations existing on the transmission path for the shift transfer. And a transmission line abnormal part display means for displaying an abnormal part of the transmission path for the shift transfer or the transmission path for the serial transfer clock.

A serial communication device according to a fifth aspect of the present invention is the serial communication device according to the fourth aspect, wherein the transmission path abnormal point display means includes a light emitting diode corresponding to an electric unit to which the plurality of slave stations belong. The transmission line for the shift transfer or the abnormal portion of the transmission line for the serial transfer clock is displayed using a light emitting diode.

A serial communication device according to a sixth aspect of the present invention is the serial communication device according to the fourth or fifth aspect, wherein the transmission path abnormal point display means is a display means provided in a system using the serial communication apparatus. Alternatively, the abnormal part is configured to be displayed on display means of a diagnostic device for diagnosing the state of the system.

According to a seventh aspect of the present invention, there is provided a method for detecting an abnormality in a serial communication apparatus, comprising a transmission line having a plurality of slave stations centered on one master station, and synchronizing with a serial transfer clock generated by the master station. Performs information exchange between the master station and the plurality of slave stations by shifting and transferring the output information to the plurality of slave stations and returning the slave information from the plurality of slave stations to the master station using the shift transfer. In a method for detecting an abnormality of a serial communication device that performs serial communication for performing
Using the shift transfer, determine the content of the slave station information returned from the slave station to the master station, and based on the determination result, a transmission path for the shift transfer or a transmission path for the serial transfer clock. It is characterized by detecting an abnormality of.

The serial communication device abnormality detecting method according to claim 8 is the serial communication device abnormality detecting method according to claim 7, wherein before performing serial communication for exchanging information with the plurality of slave stations. Perform initialization communication for recognizing the slave station arrangement order of slave stations connected to the current transmission path, and at the time of the initialization communication, based on the determination result,
When it is determined that the content other than the content of the identifier information registered in advance is received, an abnormality of the transmission path for the shift transfer or the transmission path for the serial transfer clock is detected.

According to a ninth aspect of the present invention, in the method for detecting an abnormality of a serial communication device according to the seventh aspect, before performing serial communication for executing information exchange with the plurality of slave stations, Performs initialization communication for recognizing the slave station arrangement order of slave stations connected to the current transmission path, and, at the time of the initialization communication, based on the determination result, when it is determined that predetermined identifier information content has been received. And detecting an abnormality in the transmission path for the shift transfer or the transmission path for the serial transfer clock.

The serial communication device abnormality detection method according to claim 10 is the serial communication device abnormality detection method according to any one of claims 7 to 9, wherein the serial communication device abnormality detection method exists in a transmission path for the shift transfer. When an abnormality is detected in the transmission path for the shift transfer or the transmission path for the serial transfer clock corresponding to the arrangement of a plurality of slave stations, the abnormal part is displayed.

The method for detecting an abnormality in a serial communication device according to claim 11 is the method for detecting an abnormality in a serial communication device according to claim 11, wherein the abnormality is detected by using a light emitting diode corresponding to an electric unit to which the plurality of slave stations belong. It is characterized by displaying a location.

According to a twelfth aspect of the present invention, there is provided the serial communication device abnormality detecting method according to the tenth or eleventh aspect, wherein the serial communication device uses a display unit or a display unit. The abnormal part is displayed on display means of a diagnostic device for diagnosing the state of the system.

A recording medium according to a thirteenth aspect is a serial communication device comprising a transmission line having a plurality of slave stations centered on one master station, wherein the master station is synchronized with a serial transfer clock generated by the master station. Information exchange between the master station and the plurality of slave stations by shifting and transferring output information from a station to the plurality of slave stations, and returning the slave information from the plurality of slave stations to the master station using the shift transfer. In a recording medium that records an abnormality detection program in a format readable by a computer of a serial communication device that performs serial communication for executing the abnormality detection program, the abnormality detection program is returned to the main station using the shift transfer. A return information content determining step of determining the slave station information content to be transmitted, and a transmission path or a transmission path for the shift transfer based on the determination result of the return information content determining step. Serial, characterized in that it comprises a transmission line abnormality detecting process of detecting an abnormality in the transmission path for the serial transfer clock.

The recording medium of claim 14 is the recording medium of claim 13
The recording medium according to claim 1, wherein the abnormality detection program comprises:
Before performing serial communication for performing information exchange with the plurality of slave stations, including an initialization communication step of performing initialization communication for recognizing the slave station arrangement order of slave stations connected to the current transmission path, In the transmission path abnormality detection step, during the initialization communication in the initialization communication step, based on the determination result, when it is determined that the content other than the pre-registered identifier information content has been received, the shift transfer of the Of the transmission line for the serial transfer clock or the transmission line for the serial transfer clock is detected.

The recording medium of claim 15 is the recording medium of claim 13
The recording medium according to claim 1, wherein the abnormality detection program comprises:
Before performing serial communication for performing information exchange with the plurality of slave stations, including an initialization communication step of performing initialization communication for recognizing the slave station arrangement order of slave stations connected to the current transmission path, In the transmission path abnormality detection step, during initialization communication in the initialization communication step, based on the determination result, when it is determined that predetermined identifier information content has been received, the transmission path for the shift transfer or An abnormality of a transmission line for the serial transfer clock is detected.

The recording medium of claim 16 is the recording medium of claim 13
16. The recording medium according to any one of claims 15 to 15, wherein the abnormality detection program corresponds to the arrangement of the plurality of slave stations present on the transmission path for the shift transfer, and the transmission path for the shift transfer or The method further includes a transmission line abnormal part display step of displaying an abnormal part of the transmission path for the serial transfer clock.

The recording medium according to claim 17 is the recording medium according to claim 16
In the recording medium described in the above, in the transmission path abnormal point display step, a transmission path for the shift transfer or a transmission for the serial transfer clock is used by using a light emitting diode corresponding to an electric unit to which the plurality of slave stations belong. It is characterized by displaying an abnormal part of the road.

The recording medium according to claim 18 is the recording medium according to claim 15
17. The recording medium according to claim 16, wherein, in the transmission path abnormal point display step, a display unit included in a system using the serial communication device or a display unit included in a diagnostic device that diagnoses a state of the system is provided. , The abnormal part is displayed.

[0113]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) First, a first embodiment of the present invention will be described with reference to FIGS.

Since the present embodiment can be realized by the serial communication device (FIG. 6) described as the prior art, the description will be made with reference to FIG. 6, but the serial communication device which can use the means intended by the present invention will be described. The communication device is not particularly limited to such a configuration. Further, a transmission path diagram when all slave stations that can be connected to the equipment using the serial communication apparatus are connected is configured as shown in FIG. 7 as a prior art, and the slave station of this basic transmission path is connected. The arrangement order is determined according to the equipment used, but, for example, if the arrangement sequence of the slave stations is changed due to a change in specification, etc., the basic arrangement sequence of the slave stations may be changed according to the content of the change. Is as described above.

Further, since the overall control of the serial communication device described in the present embodiment is realized by the serial communication task shown in FIG. 9 as a conventional technique, the serial control which is the main control of the serial communication device will be described in this embodiment. The description of the communication task is omitted.

FIG. 1 is a transmission path diagram showing an example of the order of arrangement of slave stations in the transmission path in the serial communication device according to the present embodiment at the present time. In the figure, the order of the slave stations in the transmission line is the order of the slave stations in the basic transmission line (FIG. 7).
On the other hand, optional electric units (in the example of FIG. 8, five electric units of a switchback unit, a high-pressure (blue) unit, a high-pressure (yellow) unit, an envelope unit, and a double-sided control unit) are optionally provided. It is used in a state where it is omitted. Further, as shown in FIG. 1, in the present embodiment, an LED (light emitting element) as a communication transmission line abnormal point display means for displaying an abnormal point on the transmission path is provided for each slave station. ON / OFF control is performed according to the state of the transfer signal. Note that the LED shown in FIG. 1 indicates the mounting position, and the LED drive circuit is very common and is omitted, but the present invention is not particularly limited to such a form. It goes without saying.

Prior to the description of this embodiment, the CP of the main station
The program form of U will be described. This program form is configured in a task-type parallel processing form. In other words, each independent control program constitutes a plurality of tasks, a memory and port initialization settings and the like are executed by CPU reset after power-on, and a program called a monitor program to execute the start operation of each task is executed. It is done. Each task is processed in parallel and executed in real time. As a prior art, the serial communication task shown in FIG. 10 is also started by the monitor program, and once a predetermined processing operation is performed, the process is once returned to the monitor program, but when it is started again, the program is executed from the continuation of the previous time. Similarly, another task temporarily stops when a predetermined processing operation is performed, but is restarted to execute a subsequent control operation. As a result, the tasks are executed in parallel by sequentially executing predetermined processing operations, and the operation of the entire apparatus is controlled. Also, the cooperation between each task is
Control processing is performed by reading and writing the contents of the memory means of each task.

A program for executing the flowcharts shown in the following description is a task that is also processed in parallel, but for the sake of simplicity, the description will be made assuming that one continuous program process is performed. .

FIG. 2 is a flowchart showing an initialization communication procedure performed in a serial communication task in the serial communication device according to the present embodiment. The initialization communication shown in FIG. 2 is started in the serial communication task shown in FIG.

First, the communication software reset is turned on,
In order to make the input selector circuit 1 of the slave station shown in FIG. 6 access the identifier information of the slave station, idle transfer (one clock) of the transfer clock is performed (step S11). When the idle transfer of the transfer clock is not performed, the input selector circuit 1 of the slave station may be configured to access the information content of the slave station. Then, the memory pointer specified for resetting the memory map and the communication abnormality flag for registering the abnormality of the communication result are each initialized to “00H” (step S12), and the memory pointer is incremented by “1” (step S1).
3) A memory address represented by a value obtained by adding a head value address (MTO) and a memory pointer value of a memory map of the slave parallel output information in which the slave array order is registered in advance, and the slave array order is registered in advance. It is determined whether or not the value is equal to the last value address (MTE) of the memory map of the slave station parallel output information (step S14). If the two values are equal, it means that the scanning of the memory map has been completed.

If it is determined in step S14 that the value of the start value address MTO is not equal to the value of the end value address MTE, preparation for output of transfer data to be shifted is performed (step S15). In this initialization communication, all-zero transfer data is shift-transferred. However, the present invention is not particularly limited to this, and data having contents other than all-zero may be shift-transferred depending on the use of the serial communication device. .

Then, 4-bit shift transfer is executed in accordance with the slave station circuit configuration. That is, one-bit shift transfer is performed, the transfer clock is transferred by one clock, and the clock number counter is incremented by "1" (step S16), and one-bit shift transfer input is performed (step S17). It is determined whether the 4-bit shift transfer has been completed (step S18). By repeating the processing procedure of steps S16 to S18, 4
Bit-wise shift transfer is performed.

In the determination in step S18, when the shift transfer of 4 bits (identifier information of one slave station) is completed,
The returned identifier information content is all 1 or all 0
Is determined (step S19). As described in the related art, the content of the identifier information is allocated in advance, and is not an all 1 or all 0 setting. Therefore, if there is no abnormality (for example, disconnection or short circuit in the transmission path) and the operation is normal, the answer to step S19 is negative (NO), and then the slave station parallel output information ( The contents of the memory address indicated by the value obtained by adding the start value address MTO of the memory map shown in FIG. 9) and the memory pointer value are picked up, and the contents of the upper 4 bits are obtained (step S20). It is compared with the 4-bit identifier information determined to be input completed, and it is determined whether or not both match (step S21).

In the determination in step S21, if they match, it is determined that there is a slave station of the identifier information registered in the slave station parallel output information of the basic memory map, so that the above-described steps S13 to S21 are performed. Is executed again, and the presence or absence of the slave station is determined based on the identifier information by the next shift transfer.

If the two do not coincide with each other in step S21, it is determined that there is no slave station of the identifier information registered in the slave parallel output information of the basic memory map. The contents of the identifier information indicated by 4 bits are cleared to all zeros (00H), which means that there is no slave station, and re-registration is performed (step S).
22). Further, by incrementing the memory pointer by "1", the slave station of the registered identifier information located next to the slave station parallel output information of the basic memory map is specified (step S23), and the process returns to step S20 described above. The existence of the slave station is determined again.

That is, the registration is deleted by setting the content of the memory area of the non-existing slave station to “00H”, and the existing slave memory area is left as it is by retaining the already registered identifier information. The array order is reset. Note that the above-described return information content determination for resetting the presence or absence of the registered slave station (steps S20 to S2)
3) corresponds to steps S129-S in FIG.
132 is the same as the procedure shown in FIG.

As described above, when the transmission path is in a normal state in which there is no disconnection or short circuit, a memory reset operation which is an original serial communication operation is executed.

When the sequence of the slave stations in the basic memory map is reset by repeating the above operation, step S14 is performed.
In the determination, the value obtained by adding the value of the memory pointer to the value of the start value address MTO reaches the value of the end value address MTE, so that the total number of transfer clocks actually output in the shift transfer in execution of the initialization communication is counted. By dividing the value of the clock number counter of the master station by 4 bits, which is the number of bits constituting the single station, the total number of slave stations present on the current transmission path is calculated. It is determined whether or not the total number of slave stations determined to be present matches (step S24).

If it is determined in step S24 that the calculated total number of slave stations matches the total number of slave stations on the reset memory map, the sequence of slave stations is normally reset by the initialization communication. The flag is set to "1" and the communication software is reset (step S25), and the initialization communication is terminated. On the other hand, if they do not match, the reset was not performed normally, so the retry counter is incremented by "1" and the communication software is reset while the reset flag remains "0" (step S26), and this procedure is temporarily terminated. Is done. When the initialization communication ends in step S25 or step S26, the serial communication task in step S103 in FIG. 10 ends once.

On the other hand, if it is determined in step S19 that the transmission path is disconnected or short-circuited,
A short-circuit routine is executed (Step S27).

When the transmission line of the serial transfer clock connected in parallel to each slave station is disconnected or short-circuited at the position of the slave station, the transfer clock is not input to the shift register of the slave station. , The return information contents from all the slave stations existing downstream from the position of the slave station are not substantially transferred. That is, the content of the identifier information is changed to all 1s or all 0s from a certain place. Similarly, when the slave station is disconnected or short-circuited at the position of the slave station in a portion where the shift transfer transmission line serially connected to each slave station is located, the master station also exists downstream from the position of the slave station. The content of the return information from all the slave stations is not substantially transferred, and the content of the identifier information becomes all 1 or all 0 from a certain point.

That is, for example, when the transmission path between the slave station 27 (high voltage 1) and the slave station 29 (high voltage red) is disconnected in the transmission path shown in FIG. The information content to be transmitted is from slave station 33 to slave station 2
Up to 9 is returned normally. However, the contents of the return information from the slave station 27 to the slave station 22 located on the transmission path downstream of the slave station 29 are not returned to the master station 21 and are substantially all ones or all zeros.

Therefore, in step S27, the main station (CP
In U) 21, by providing a means for determining whether the information content is all 1 or all 0, it is possible to easily determine the disconnection or short circuit of the transmission path without increasing the cost. .

FIG. 3 is a flowchart showing a disconnection / short-circuiting procedure performed in step S27 of FIG.

If there is a disconnection or short circuit in the transmission path, a program step jump is executed from step S19 in FIG. 2 to step S27, and the processing shown in FIG. 3 is started.

First, by determining whether or not the wiring abnormality counter has a predetermined value abnormality, it is determined whether or not the disconnection / short-circuit state of the transmission path determined in step S19 is erroneously detected due to noise or the like. Is determined (step S3
1). Here, if a disconnection or a short circuit occurs in the transmission line, the procedure jumps from step S19 in FIG. 2 to this procedure, so that the wiring abnormality counter for counting how many times this procedure has been performed is performed. By checking the counter value, it is determined whether an erroneous detection has been made.

If it is determined in step S31 that the wiring abnormality counter is smaller than the predetermined value, the wiring abnormality counter value is incremented by "1" (step S32), and the reset flag is set to "0" in order to retry the initialization communication. ”, And communication software reset is performed (step S33), and then this procedure is terminated. If it is determined that the transmission line is not in the disconnected / short circuit state while the wiring abnormality counter value is less than the predetermined value, the initialization communication is terminated, the process is shifted to the normal communication, and the serial communication is executed.

If it is determined in step S31 that the value of the wiring abnormality counter is equal to or greater than a predetermined value, it is determined that the transmission line is disconnected or short-circuited, and a communication abnormality that controls abnormal operation processing of the serial communication device is determined. The corresponding bit indicating the disconnection / short circuit of the transmission line in the flag is set to a predetermined value (step S34). Then, from the memory contents shown in FIG. 9, analysis control for determining which part in the transmission path is disconnected or short-circuited is started.

When this procedure is being executed, the procedure jumps to this procedure in the course of resetting the initialization communication. Therefore, the memory pointer indicates a portion (slave station) in the transmission path where a disconnection or short circuit occurs. The value is being held. Therefore, by counting the number of memory settings up to the value indicated by the memory pointer, it is possible to determine from the contents of the memory which part of the transmission path is disconnected or short-circuited.

More specifically, first, a detection pointer used as a substitute for a memory pointer for memory operation, and an abnormal slave station counter indicating the order of the slave station belonging to the current slave station connected to the current transmission line. Then, a display instruction counter for displaying the abnormal slave station is initialized to "00H" (step S35). Then, in step S35, "00"
The detection pointer initialized to "H" is incremented (step S36), whereby the memory content access is set to the initial position. In this state, the contents of the memory address indicated by the sum of the start value address MTO of the memory map, which is the slave-station parallel output information of the basic memory map, and the value of the detection pointer are picked up, and the upper 4 bits of the contents are picked up. The content is obtained (step S37),
It is determined whether the value is "00H" (step S38).

If it is not "00H" in the determination at step S38, the slave station currently being checked for abnormality is normal, and the abnormal slave station counter is incremented by "1" (step S39). Step S3
If the determination in step 8 is "00H", step S39 is reached.
Is skipped.

In order to determine whether or not the abnormality check of the slave station corresponding to the memory that has already been reset at this time has been completed, the value of the memory pointer stored and held during the resetting is detected. Is determined (step S40), and if not, the process of step S36 is performed again. If the value of the memory pointer is equal to the value of the detection pointer, it is determined that the abnormality check has been completed.

As a result of this processing, the abnormal slave station counter contains:
The number of slave stations that are determined to be present in the current transmission path and that are determined to be not disconnected or short-circuited (that is, the transmission path is connected to the master station) is counted. Therefore, the abnormal slave station counter value is stored in the memory (step S41). With the above processing, the self-diagnosis of the transmission path abnormality is completed.

That is, this transmission path abnormality accident diagnosis is performed by maintaining the state interrupted by the disconnection or short circuit of the transmission path during resetting of the slave station connected to the current transmission path, and by the time the transmission path is interrupted. By counting the number of slave stations confirmed to be in the above order, it is possible to check the normal order in the slave station arrangement order of the current transmission line, and thereby to detect the disconnection / short-circuit position of the transmission line.

When the number of the disconnection / short-circuit position of the transmission line in the sequence of the slave stations is stored and held by the processing of step S41, the serviceman can easily visually recognize the transmission line abnormal portion of the serial communication device. Then, a process of displaying an abnormal part using the LED shown in FIG. 1 is performed so that the unit can be replaced in a short time.

That is, shift transfer is performed with the content that the LED is turned on, the display instruction counter is incremented by "1" (step S42), and the value of the display instruction counter is set to the total number of slave stations connectable to the transmission line (memory). Is determined to be equal to four times the number of slave stations in the state before resetting to (step S43). This is to check whether or not the number of shift transfer bits of one 4-bit configuration sentence has been transferred to the number of slaves that can be connected to the transmission line. Done to output. Steps S42 and S4 are performed until the shift transfer of the LED-on instruction is completed.
Step 3 is repeated.

As a result, the LED of the normal slave station, which is not affected by the disconnection / short circuit on the transmission line, is turned on, but the LED of the slave station, which cannot be transmitted, is affected by the disconnection / short circuit of the transmission path, is turned off. For example, when there is a disconnection between the slave station 27 and the slave station 29, the LED-on output from the master station 21 is transmitted to the slave stations 22, 23, 25, and 27, and the LEDs included therein are turned on. . However, slave station 29,
Since the LED ON output from the main station 21 is not transmitted to 32 and 33, the associated LED is not turned on. Therefore, at the time of maintenance of the serial communication device, by visually observing the LED lighting, it is possible to easily recognize the location where the transmission line is disconnected or short-circuited. Note that the disconnection / short-circuit state of the transmission line is not resolved even once the power of the device is turned off, and can be immediately confirmed by turning on the power at the time of maintenance by a serviceman.

Thereafter, a communication failure processing routine is executed (step S44), and this procedure is terminated, whereby the serial communication task is terminated.

As described above, according to the present embodiment, the self-diagnosis of the normal communication state due to the disconnection / short-circuit of the transmission line can be easily performed, and the result of the self-diagnosis is notified to the service person at low cost. be able to. Thereby, maintenance can be performed in a short time.

It should be noted that any other means may be used for the indication of the abnormal location by the LED display provided on the transmission line as long as the abnormal location can be specified. For example, as a display means that can be recognized by a serviceman, by using a segment display unit of the operation display unit of the device device that the device device has, by displaying the information content of the abnormal slave station count value on this,
At a glance, a serviceman can recognize the position of the disconnection or short circuit of the transmission line in the order of arrangement of the slave stations. Further, by providing a display unit on a check jig of an equipment used for installation of the equipment, for example, the value of the abnormal slave station count value can be displayed in the same manner as described above.
It goes without saying that the LED provided in the transmission path may be prepared in a jig and displayed using the checker shown in FIG.

(Second Embodiment) Next, a second embodiment of the present invention will be described with reference to FIGS.

In the present embodiment, as in the first embodiment described above, the transmission path abnormality is determined in the step of determining the reply information content, and the transmission path abnormality self-diagnosis is performed and the communication transmission path abnormality location is displayed. In contrast, in the first embodiment, the serial communication operation determines the return information content during execution of the initialization communication to detect a disconnection or a short circuit in the transmission path. After completion of the process, the return information content is determined during the execution of the normal communication for exchanging information with the information content of each slave station, thereby detecting the disconnection or short circuit of the transmission path. That is, the present embodiment is different from the first embodiment in the timing of executing the return information content determination.

FIGS. 4 and 5 are flowcharts showing a normal communication procedure executed in the serial communication device according to the present embodiment.

In the normal communication according to the present embodiment, when each slave station information returned to the master station is stored in the memory by executing the shift transfer, the disconnection of the transmission line is checked. In order to perform a disconnection check of a transmission line in normal communication, a form that satisfies the following prerequisites is required.

The precondition is that, when the disconnection check in the present embodiment is performed, as described in the conventional example, information exchange with each slave station that executes normal communication includes all 1 or all 0 in the information content. Any state signal can be returned, including:

That is, this is different from the state in which the information contents normally returned as in the first embodiment do not include all 1s or all 0s. Therefore, in order to recognize the disconnection of the transmission line in the execution of the normal communication, it is necessary to provide a fixed value bit in the information content returned from each slave station. Here, one bit of the 4-bit configuration adds information content fixed to zero. As a result, the content of the return information from the slave station having the 4-bit configuration is composed of the 3-bit information and the 1-bit fixed value. As described above, it is necessary to realize a configuration in which the content of the return information from the slave station does not become all 1 under the preconditions. Note that, in order to configure so that the fixed value bit is “0”, all 1s are set, and when the fixed value bit is set to 1, all 0s are not included in the return information content. Must be selected in advance. Further, the content of the return information from the slave station of 4-bit configuration is 2
Assuming that the bits are information and the two bits are fixed values (both 1 and 0), similarly to the first embodiment, the information content returned normally does not include all 1s or all 0s. Is possible.

In the present embodiment, among the preconditions described above, a case will be described where the 4-bit return information content is composed of 3-bit information and a 1-bit fixed value "0". That is, when the return information content is determined to be all 1, it is determined that an abnormality has occurred in the transmission path.

In FIG. 4, when the normal communication procedure is started, a communication software reset is first performed to synchronize the execution of communication (step S51). Further, the communication abnormality flag, the memory pointer, the phase control counter, and the clock number counter are reset to “00H” (step S52). Then, the memory pointer for the memory operation is incremented (step S5).
3) The control counter value is loaded from the main station phase control counter (step S54), and it is determined whether the control counter value is a predetermined value (step S55). Here, the discrimination is performed based on the binary value of "06H" when the shift transfer from the slave station is selected and "00H" when the shift input is selected. Further, the result of the double reading comparison after performing the shift transfer twice has been described as "0D
H ", which is used for determination in steps described later. On the other hand, the validity period of the slave station communication request signal is set to “0EH”. Here, although the timing determination is not particularly performed, the communication operation in the normal communication ends.
Control is performed so that the communication executable state is set to “0EH” next time.

If it is determined in step S155 that the control count value is the predetermined value, it is determined whether or not the return phase signal is ON (step S56). It is determined that the phase timing is normally synchronized, and the process of step S60 is performed.

On the other hand, if it is determined in step S55 that the control count value is not the predetermined value, it is determined whether or not the return phase signal is turned off (step S57). If so, it is determined that the phase timing is normally synchronized.
Step S60 is performed.

If it is determined in step S56 that the return phase signal is off at the time of on-check, or if step S5
If the return phase signal is on when the return phase signal is off-checked in the determination of 7, it is determined that the phase timing is out of synchronization. Therefore, "1" is set to the phase error bit of the communication abnormality flag (step S58), the communication software reset is turned on (step S59), and the normal communication is canceled.

When it is determined in step S56 or S57 that the return phase signal is normal, normal communication is started.

First, it is determined whether or not the sum of the memory pointer value and the head value address MTO of the reset-completed memory map indicated by the slave station parallel output information is equal to the final value address MTE of the memory map. Step S6
0).

In this discrimination, if they are not equal, the shift transfer has not been completed yet, so the upper 4 bits of the memory contents indicated by the sum value address of the memory pointer value and the top value address MTO of the memory map are obtained. (Step S61), and it is determined whether or not the value is "00H" (step S62). Here, if it is “00H”, there is no slave station registered by the resetting, so the flow returns to step S53 again, the memory pointer value is incremented, and shift transfer at the next slave station in the memory map is started.

In the determination in step S62, "00"
If not "H", the lower 4 bits of the memory content are obtained (step S63), and one-bit shift is performed for shift transfer (step S64). That is,
In step S64, the contents of one bit are shifted out, one transfer clock is output, and the clock number counter is incremented by "1". Further, it is determined whether the value of the clock number counter means of the master station is a predetermined value (step S65). If the value is the predetermined value, the control count values of the phase control counters of the master station and the slave stations are respectively determined. "1" is incremented (step S66). On the other hand, if it is determined in step S65 that the value of the clock number counter is not the predetermined value, the process of step S66 is skipped. Then, a 1-bit return signal from the shift transfer is input (step S6).
7) It is determined whether or not 4-bit shift transfer corresponding to one slave station has been completed (step S68). If it is determined in this determination that the 4-bit shift transfer has not been completed, step S64 is performed again.

If the shift transfer of 4 bits (for one slave station) is completed in the determination in step S68, it is determined whether or not the 4-bit data is all 1s (step S69).

If the result of this determination is all 1s, the current state of normal communication is maintained, and the disconnection / short circuit routine is executed (step S71). This process is executed according to the flowchart shown in FIG. 3 of the first embodiment.

As described above, according to the present embodiment, the self-diagnosis of the disconnection state of the transmission path of the shift transfer can be always performed even when the normal communication means is executed.

If it is not all 1 in the determination in step S69, it is determined that the content of the slave station return information is normal, and
The processing after step S70 is performed. That is, the input 4-bit data is stored in the slave station parallel input information of the memory map shown in FIG. 9D (step S6).
9). Specifically, the shift-transferred 4-bit data is stored in the lower 4 bits of the memory content indicated by the sum value address of the memory pointer value and the start value address MTI of the memory map of the slave station parallel input information. By
The information content is updated. Then, in order to repeat the above operation in order to execute the shift transfer of the slave station, step S is executed again.
53 is executed. Then, as described above, if it is determined in step S60 that the data scan of the slave station to be shifted and transferred has completed one cycle, processing after execution of normal communication is performed.

That is, the control counter value of the phase control counter is set to "0DH" (step S72), and it is determined whether or not the return phase signal is on (step S73). In this determination, if the return phase signal is ON, it means that an error has occurred in the double reading comparison in any of the slave stations, so the double reading comparison error bit of the communication abnormality flag is set ( Step S7
4), a communication software reset for executing retry communication is executed (step S75), and the procedure is thereafter terminated.

On the other hand, if the return phase signal is not turned on in the determination of step S73, it means that no error has occurred in the double reading comparison in all the slave stations.
The control count value of the master station phase control counter is set to "0EH" (step S76), the communication request signal from each slave station is set to be valid, and this procedure ends.

As described above, according to the present embodiment, the transmission path abnormality self-diagnosis processing can be executed even during normal communication.

Note that the self-diagnosis for disconnection and short-circuit of the communication transmission line in this embodiment is only a configuration that is checked when serial communication is started (a configuration that is executed at the time of initialization communication in the first embodiment). Although sufficient, it goes without saying that the configuration may be such that it is executed only during normal communication as in the present embodiment. Further, in combination with the first embodiment, the self-diagnosis may be performed both during the initialization communication and during the normal communication.

(Other Embodiments) According to the present invention, a storage medium storing a program code of software for realizing the functions of the above-described embodiments is supplied to a serial communication device, and a CPU of the serial communication device stores the program code. It goes without saying that the object of the present invention is also achieved by reading and executing the program code stored in the medium.

In this case, the program code itself read from the storage medium realizes the novel function of the present invention, and the storage medium storing the program code constitutes the present invention.

As a storage medium for supplying the program code, for example, a floppy disk, hard disk, optical disk, magneto-optical disk, CD-ROM, CD
-R, a magnetic tape, a nonvolatile memory card, a ROM, or the like can be used.

Further, not only the functions of the above-described embodiment are realized by the computer executing the readout program code, but also the OS or the like running on the computer is actually executed based on the instruction of the program code. It goes without saying that a part or all of the above processing is performed, and the function of the above-described embodiment is realized by the processing.

Further, after the program code read from the storage medium is written into a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer, the program code is read based on the instruction of the program code. Needless to say, a CPU or the like provided in the function expansion board or the function expansion unit performs part or all of the actual processing, and the processing realizes the functions of the above-described embodiments.

[0179]

As described above, according to the abnormality detection method for the serial communication device according to the first to third aspects or the serial communication device according to the seventh to ninth aspects, the slave station returns to the master station using shift transfer. The contents of the slave station information
Since the abnormality of the transmission line for the shift transfer or the transmission line for the serial transfer clock is detected based on the determination result, the abnormality of the slave station due to disconnection or short circuit of the transmission line can be more easily detected. The effect that it can be obtained is obtained.

According to the serial communication device according to claims 4 to 6 or the abnormality detection method for serial communication devices according to claims 10 to 12, it is possible to correspond to the arrangement of the plurality of slave stations existing on the transmission path for the shift transfer. When an abnormality is detected in the transmission line for the shift transfer or the transmission line for the serial transfer clock, the abnormal portion is displayed, so that abnormality due to disconnection or short circuit in the transmission line can be easily performed. Self-diagnosis can be performed, and the result of the self-diagnosis can be notified to a service person at low cost. As a result, an effect that maintenance can be performed in a short time is obtained.

According to the recording medium of claims 13 to 15,
A serial communication device including a transmission line having a plurality of slave stations centered on one master station, wherein output information from the master station to the plurality of slave stations is synchronized with a serial transfer clock generated by the master station. Serial communication for performing shift transfer and performing serial communication for performing information exchange between the master station and the plurality of slave stations by returning slave station information from the plurality of slave stations to the master station using the shift transfer. In a recording medium recording an abnormality detection program in a format readable by a computer of the apparatus, the abnormality detection program determines the content of slave station information returned to the master station using the shift transfer. A transmission step for the shift transfer or a transmission for the serial transfer clock based on a determination result of the determination step and the return information content determination step. And a transmission line abnormality detecting step of detecting an abnormality of the serial communication device, so that the computer of the conventional serial communication apparatus reads and executes the abnormality detection program recorded on the recording medium. The same effects as those of the serial communication devices of Nos. 1 to 3 can be obtained.

According to the recording medium of claims 16 to 18,
The abnormality detection program is configured to detect an abnormal portion of the transmission path for the shift transfer or the transmission path for the serial transfer clock in accordance with the arrangement of the plurality of slave stations present on the transmission path for the shift transfer. 7. The method according to claim 4, further comprising the step of displaying a transmission path abnormality location displaying step, by causing a computer of the conventional serial communication apparatus to read and execute an abnormality detection program recorded on the recording medium. The same effect as that of the serial communication device can be obtained.

[Brief description of the drawings]

FIG. 1 is a transmission path diagram showing an example of a sequence of arrangements of slave stations in a current state of a transmission path in a serial communication device according to a first embodiment of the present invention.

FIG. 2 is a flowchart showing an initialization communication procedure performed in a serial communication task in the serial communication device according to the embodiment.

FIG. 3 is a flowchart showing a disconnection / short-circuit processing procedure performed in step S27 of FIG. 2;

FIG. 4 is a flowchart showing a normal communication procedure executed in a serial communication device according to a second embodiment of the present invention.

FIG. 5 is a flowchart showing a normal communication procedure executed in the serial communication device according to the embodiment.

FIG. 6 is a block diagram showing a conventional slave station configuration.

FIG. 7 is a transmission path diagram when all slave stations that can be connected to a device using a conventional serial communication device are connected.

FIG. 8 is a transmission path diagram showing an example of the order of arrangement of slave stations in a current state of a transmission path in a serial communication device when a certain device actually operates.

FIG. 9 is a conceptual diagram of a memory map used when the serial communication device performs information exchange.

FIG. 10 is a flowchart showing a serial communication task when performing serial communication in a conventional serial communication device.

FIG. 11 is a flowchart showing an initialization communication procedure when performing conventional serial communication.

FIG. 12 is a flowchart showing a normal communication procedure when performing conventional serial communication.

FIG. 13 is a flowchart showing a normal communication procedure when performing conventional serial communication.

[Explanation of symbols]

 21 Master station 22-33 Slave station

Claims (18)

[Claims] 1. A serial communication apparatus comprising a transmission line having a plurality of slave stations centered on one master station, wherein the plurality of slave stations are transmitted from the master station in synchronization with a serial transfer clock generated by the master station. Serial transfer for performing information exchange between the master station and the plurality of slave stations by shifting the output information to the master station and returning slave station information from the plurality of slave stations to the master station using the shift transfer. In the serial communication device for performing communication, the master station uses return information to determine the content of slave station information returned to the master station using the shift transfer. A transmission path abnormality detecting means for detecting an abnormality in the transmission path for the shift transfer or the transmission path for the serial transfer clock based on the result. Place. 2. An initialization for recognizing an arrangement sequence of slave stations connected to a current transmission line before performing serial communication for executing information exchange with the plurality of slave stations. Initializing communication means for performing communication, the transmission path abnormality detecting means, based on the determination result of the return information content determining means at the time of initialization communication by the initializing communication means, other than the content of identifier information registered in advance The serial device according to claim 1, wherein when it is determined that the content of the serial transfer has been received, an abnormality in the transmission line for the shift transfer or the transmission line for the serial transfer clock is detected. Communication device. 3. An initialization for recognizing an arrangement sequence of slave stations connected to a current transmission line before performing serial communication for executing information exchange with the plurality of slave stations. Comprising an initialization communication means for performing communication, the transmission path abnormality detection means, at the time of initialization communication by the initialization communication means, based on a determination result of the return information content determination means, received a predetermined identifier information content 2. The serial communication device according to claim 1, wherein when it is determined that the transmission path for the shift transfer or the transmission path for the serial transfer clock is abnormal. 4. An abnormal portion of the transmission path for the shift transfer or the transmission path for the serial transfer clock is displayed in correspondence with the arrangement of the plurality of slave stations existing on the transmission path for the shift transfer. The serial communication device according to any one of claims 1 to 3, further comprising a transmission line abnormality location display unit that performs the operation. 5. The transmission path abnormal point display means includes a light emitting diode corresponding to an electric unit to which the plurality of slave stations belong, and using the light emitting diode, a transmission path for the shift transfer or the serial transfer clock. 5. The serial communication device according to claim 4, wherein the communication device is configured to display an abnormal portion of the transmission path for the communication. 6. The abnormal location of the transmission path is displayed on a display of a system using the serial communication device or a display of a diagnostic device for diagnosing the state of the system. The serial communication device according to claim 4, wherein the serial communication device is configured to display the following. 7. A transmission path having a plurality of slave stations centered on one master station, and shift-transferring output information from the master station to the plurality of slave stations in synchronization with a serial transfer clock generated by the master station. And a serial communication device that performs serial communication for executing information exchange between the master station and the plurality of slave stations by returning slave station information from the plurality of slave stations to the master station using the shift transfer. In the abnormality detection method, the content of slave information returned from the slave to the master using the shift transfer is determined, and a transmission path or the serial transfer clock for the shift transfer is determined based on the determination result. For detecting an abnormality in a transmission path for a serial communication device. 8. Prior to performing serial communication for exchanging information with the plurality of slave stations, initialization communication for recognizing a slave station arrangement order of slave stations connected to a current transmission path is performed, At the time of initialization communication, based on the determination result,
8. An abnormality in the transmission path for the shift transfer or the transmission path for the serial transfer clock when it is determined that the content other than the content of the identifier information registered in advance is received. The method for detecting an abnormality of the serial communication device described in the above. 9. An initialization communication for recognizing a slave station arrangement order of slave stations connected to a current transmission line before performing serial communication for exchanging information with the plurality of slave stations, At the time of initialization communication, based on the determination result,
8. The serial communication device according to claim 7, wherein when it is determined that a predetermined identifier information content is received, an abnormality of the transmission path for the shift transfer or the transmission path for the serial transfer clock is detected. Abnormality detection method. 10. An abnormality in the transmission path for the shift transfer or the transmission path for the serial transfer clock is detected in accordance with the arrangement of the plurality of slave stations present on the transmission path for the shift transfer. 10. The method for detecting an abnormality in a serial communication device according to claim 7, wherein the abnormal point is displayed at the time. 11. The abnormality detection method for a serial communication device according to claim 11, wherein the abnormal location is displayed using a light emitting diode corresponding to an electric unit to which the plurality of slave stations belong. 12. The abnormal part is displayed on display means of a system using the serial communication device or display means of a diagnostic device for diagnosing the state of the system. Item 12. The method for detecting an abnormality in a serial communication device according to item 10 or 11. 13. A serial communication device comprising a transmission line having a plurality of slave stations centering on one master station, wherein the plurality of slave stations are transmitted from the master station in synchronization with a serial transfer clock generated by the master station. Serial transfer for performing information exchange between the master station and the plurality of slave stations by shifting the output information to the master station and returning slave station information from the plurality of slave stations to the master station using the shift transfer. In a recording medium recording an abnormality detection program in a format readable by a computer of a serial communication device that performs communication, the abnormality detection program stores the content of slave station information returned to the master station using the shift transfer. A return information content determining step of determining, and a transmission path for the shift transfer or the serial transfer clock based on the determination result of the return information content determining step. Recording medium, characterized in that it comprises a transmission line abnormality detecting process of detecting an abnormality in the transmission path for the click. 14. The abnormality detection program according to claim 1, further comprising: an initializing step for recognizing a slave station arrangement order of slave stations connected to a current transmission line before performing serial communication for exchanging information with the plurality of slave stations. Comprising an initialization communication step of performing an initialized communication, In the transmission path abnormality detection step, at the time of the initialization communication in the initialization communication step, based on the determination result,
14. An abnormality in the transmission path for the shift transfer or the transmission path for the serial transfer clock is detected when it is determined that the content other than the content of the identifier information registered in advance is received. The recording medium according to the above. 15. The abnormality detection program according to claim 1, further comprising: an initializing step for recognizing an arrangement sequence of the slave stations connected to the current transmission path before performing serial communication for exchanging information with the plurality of slave stations. In the transmission path abnormality detection step, during the initialization communication in the initialization communication step, when it is determined that predetermined identifier information content has been received based on the determination result 14. The recording medium according to claim 13, wherein an abnormality of the transmission path for the shift transfer or the transmission path for the serial transfer clock is detected. 16. The transmission program for the shift transfer or the transmission for the serial transfer clock in accordance with the arrangement of the plurality of slave stations present on the transmission line for the shift transfer. The recording medium according to any one of claims 13 to 15, further comprising a transmission path abnormal point display step of displaying a path abnormal point. 17. The transmission path for the shift transfer or the transmission path for the serial transfer clock using the light emitting diode corresponding to the electric unit to which the plurality of slave stations belong in the transmission path abnormal part display step. 17. The recording medium according to claim 16, wherein the abnormal part is displayed. 18. The method according to claim 18, wherein the step of displaying the location of the transmission line abnormality includes displaying the abnormality on display means of a system using the serial communication device or display means of a diagnostic device for diagnosing the state of the system. 17. The recording medium according to claim 15, wherein a location is displayed.