JPH0673939U - Communication bus controller - Google Patents

Abstract

(57) [Summary] (Modified) [Purpose] To improve the usage efficiency of the communication bus. [Configuration] Baton confirmation unit that updates the connected device list according to the source address and destination address, own station baton generation unit that detects whether the received baton is addressed to the own station, destination address, own station address and connection The device list refers to the carrier generation unit that sends the carrier to the communication bus when the destination address does not include its own address, the carrier confirmation unit that receives the carrier from another device on the communication bus, and the carrier reception If there is a detection output of the local station baton generator, the destination address is added to the baton, and if there is carrier reception and there is a detection output of the local station baton generator, an address not stored in the connected device list is added. A baton generator is provided that is added to the baton as a destination address and is sent to the communication bus.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a baton path type communication bus control device that uses a communication bus when it is connected to a communication bus to orbit a baton, and when the baton comes around to itself, more specifically, It is intended to improve the bus usage efficiency.

[0002]

[Prior art]

 In the baton-pass communication, the right to use the communication bus is granted only when the baton comes to its own station in the device connected to the communication bus. It is a method of waiting for batons to come back to its own station, after passing the batons to other devices, using the communication buses one after another. In the baton path communication bus currently used, the maximum number N of connectable devices is determined, and, for example, addresses 1 → 2, 2 → 3, ..., N−1 → N, in the device number (address) order. The batons are cycled in the order of N → 1, 1 → 2, .... Then, the device that receives the baton addressed to itself is using the communication bus. Further, the baton path method is constructed so that the baton is transmitted even if the device having the device number designated by the baton is not connected to the communication bus. For example, if the maximum number of devices N = 4 and three devices with device numbers 1, 3, and 4 are connected, a baton destined for the device with device number 2 from device number 1 will be sent. Although it is sent, the device with device number 2 is not actually connected, so the device with device number 1 detects that there is no response to this baton, and sends the baton again to the device with the next device number 3. . As a result, the device with the device number 3 responds and the patrol of the baton can be continued. In this way, the baton will be sent even if a new device is additionally connected to the position of the vacant number of the communication bus during the operation of the device, and this new device can also participate in the baton path method. is there.

[0003]

[Problems to be Solved by the Invention] The following problems existed in such a conventional technique. That is, if the maximum number of devices N is large and the number of connected devices is small, most of the batons sent from each device are non-response batons, and the use efficiency of the baton and the communication bus deteriorates. was there. In order to solve this problem, the applicant of the present application has proposed “Paton path communication bus control device” of Japanese Patent Application No. 2-77933 (Kaikai No. 4-36346), and all the devices connected to the communication bus are proposed. For devices that have been added to the device list after being registered in the connected device list, collision data will be generated by the device when there is no baton for the device, and then a new broadcast will be performed. We have disclosed a method in which the device sends its device number (address) and each device updates its internal connected device list. However, even with this method, a new pattern that "I am not connected and will perform broadcast communication from now on" is generated as collision data, and collision data that detects this collision data is generated. The detection circuit had to be newly installed, and there was a problem that the device configuration became complicated in order to realize it.

The present invention solves such a problem, and even when a new device is additionally connected, the baton is sent to this device with a simple configuration, thereby performing communication. The purpose is to improve the bus usage efficiency.

[0005]

[Means for Solving the Problems]

 The configuration of the present invention which achieves such an object has a connected device list which is connected to the communication bus and registers all devices connected to the communication bus in a list format, and also has a source address and a destination. In the communication bus control unit that circulates the baton including the address and obtains the right to use the communication bus when the baton comes around, the baton confirmation unit that updates the connected device list according to the source address and the destination address in the baton. Then, the baton confirmation unit compares the destination address from the baton confirmation unit with the own station address to detect whether the received baton is addressed to the own station, and the baton completes a loop from the baton confirmation unit. Sends the carrier to the communication bus when the destination address does not include the own station address by referring to the destination address, own station address and connected device list of If there is no carrier reception in the carrier confirmation section that receives a carrier from another device on the communication bus, and there is no carrier reception in the carrier confirmation section and the detection output of the local station baton generation section, the connected device list is displayed. If the destination address is added to the button and the carrier is received by the carrier confirmation section and the detection output of the local station baton generation section is detected, an address not stored in the connected device list is added to the button as the destination address. The communication bus control device is characterized by including a baton generation unit for transmitting the data to the communication bus.

[0006]

[Action]

 When the carrier sent from the newly added device is detected, the communication bus control device of the present invention sends the baton with the address not registered in the connected device list as the destination address, and returns the response. The device number of the new device is registered in the connected device list by the baton.

[0007]

【Example】

 Hereinafter, the present invention will be described in detail with reference to the drawings. FIG. 1 is a configuration block diagram of a communication bus control device 10 embodying the present invention. In this figure, an example is shown in which one communication bus control device 10 of the present invention is connected to the communication bus B, but in reality, a plurality of such communication bus control devices are connected to the communication bus B. It is assumed that the baton that permits the use of the communication bus B is circulated. The communication bus control device 10 of the present invention includes a receiver 2 that receives a baton from the communication bus B, a reception processing unit 3 that processes various information received by the receiver 2, a driver 4 that sends a baton to the communication bus B, and a driver 4. A transmission processing unit 5 for generating various information to be transmitted, a connection device list 6 for registering the numbers of all devices connected to the communication bus B in a list format, and a device number (address of the communication bus control device 10). ), The destination address of the received baton is compared with the own address of the own address section 7 to detect whether this baton is for the device 10 or not. The unit 8 is provided. These components are the same as those of the conventional device, and the device of the present invention is particularly characterized by the internal configurations of the reception processing unit 3 and the transmission processing unit 5.

The reception processing unit 3 handles the baton received from the communication bus B, and updates the contents of the connected device list 6 according to the contents of the baton (source address, destination address), and a baton confirmation unit 31. The carrier confirmation unit 32 detects a carrier from another device on the communication bus B.

Here, the carrier, including the communication bus control device 10, is a device connected to the communication bus B, and is sent from the transmission processing unit 5 when the baton addressed to the own station is not detected. The data. Unlike the conventional collision data, the collision data is data having a predetermined complicated pattern such as a start signal for interrupting the baton patrol and performing broadcast communication. The carrier in the present invention is a simple "H" or "L" pattern that is not particularly defined for the high impedance state indicating that the communication bus B is not in use. That is, the carrier here is some pattern that is detected in the idle state of the communication bus B during the patrol of the baton, and each device connected to the communication bus B by this carrier is a new device. Find out that an additional connection has been made.

The transmission processing unit 5 does not specify the own address as the destination address from the baton confirmation unit 31 even if the baton makes one round, and the transmission source address of the device concerned exists on the connected device list 6. In the case of the previous station, it has a carrier generation unit 51 that generates a carrier and a baton generation unit 52 that generates a baton for the next device. More specifically, the baton generation unit 52 refers to the connected device list 6 when there is no carrier detection by the carrier confirmation unit 32 and there is an output from the local station baton generation unit 8 indicating that it is a local station addressed baton. Then, a baton for the device to which the baton is to be transmitted next is generated, carrier detection is performed by the carrier confirmation unit 32, and there is an output from the local station baton generation unit 8 indicating that the baton is the local station. 2 is a block for generating batons for devices corresponding to addresses not registered in the connected device list 6.

Next, the operation of the device of the present invention configured as described above will be described with reference to the flow charts of FIGS. 2, 3 and 4. FIG. 2 is a flow chart showing the flow of the normal operation and the flow of detecting the carrier on the communication bus B and sending the baton to the newly added device. First, the normal operation when a new device is not additionally connected to the communication bus B will be described. The baton confirmation unit 31 of the reception processing unit 3 detects whether or not the baton is received on the communication bus B via the receiver 2 within a predetermined fixed time. When the baton cannot be detected, "N" will be described later as a flow of. When the baton is received within a certain time, “Y” indicates that the baton confirmation unit 31 looks at the source address in the baton, and if this source address is not registered in the connected device list 6, the source The contents of the connected device list 6 are updated to correspond to the address.

Next, the baton confirmation unit 31 checks the destination address in this baton. When this destination address is not addressed to this device (own station), "N" will be described later as a flow of. When it is addressed to its own station, "Y" updates this connected device list 6 if this own station address is not registered in the connected device list 6.

On the other hand, the carrier confirmation unit 32 checks whether or not the carrier from another device is continuously transmitted to the communication bus B for a predetermined time, and if the carrier is not detected at this time. , To that effect to the transmission processing unit 5. Then, when the received baton is addressed to the own station and the carrier is not detected, the baton generation unit 52 performs normal data communication, and the device number to which the baton is to be transmitted next from the connected device list 6. (NXA) is read, a new baton is generated, and the new baton is sent to the communication bus B via the driver 4.

In addition, when the carrier confirmation unit 32 detects a carrier from another device for a certain period of time, the flow is as follows. That is, the integer n = own station address MYA is set, and the maximum number N of devices and the number n are compared. As a result of the comparison, if they do not match (“N”) n = n + 1, and if they match (“Y”) n = 1, the connected device list 6 is referred to, and this value n is Then, it is checked whether or not it is equal to the device number NXA for sending the baton. Here, if n = NXA, it is found that the device to which the baton is to be transmitted next is in the connected device list 6, and the process returns to the first step of this flowchart for normal operation. When n = NXA is not satisfied and the device having the device number n is not registered in the connected device list 6, the baton generator 52 sends a baton to the device number n.

If the baton is received within a certain time, “Y”, the baton confirmation unit 31 returns to the step of checking the source address in the baton, and the source address must be listed in the connected device list 6. For example, the device number n is registered in this connected device list 6. When the baton is not received within a certain time, “N” compares the maximum number N of devices with the number n, sets n = n + 1 or n = 1, and sends the baton to this device number n. Repeat the same procedure as above.

That is, when a baton is coming to the communication bus control device 10 and a carrier is detected on the communication bus B, an address obtained by adding 1 to the device number (address) MYA of the device 10 or If the address of the device 10 is the maximum number N of devices, a baton with the address "1" as the destination address NXA is sent out, and if the baton responding to this is not returned within a fixed time, the destination address Is repeated and the baton is transmitted, and when the response baton is returned, the contents of the connected device list 6 are updated with the source address in the baton. As a result, the device number of the newly connected device can be additionally registered in the connected device list 6, and from now on, the batons will be circulated to all devices including the newly connected device. You can

FIG. 3 is a flow chart when no baton is circulated on the communication bus B. The first step in the flow chart of FIG. 2, that is, when the baton cannot be received within a fixed time, it is activated. This is the operation performed. In this case, the own station address MYA of the communication bus control device 10 is set to an integer n, and the contents of the connected device list 6 are cleared once. Then, the maximum device number N and the number n are compared, and if they do not match, (“N”) n = n + 1, and if they match, (“Y”) n = 1, and this value n Check if it is equal to the address M YA.

Here, if n = MYA (“Y”), the process returns to the step of the flowchart of FIG. If n = MYA is not satisfied (“N”), the baton generator 52 sends the baton to the device number n. When the response baton is received within the fixed time, “Y” returns to the flow chart step of FIG. 2, and when the response baton is not received within the fixed time, “N” is the maximum number N of devices. The number n is compared, n = n + 1 or n = 1 is set, and the procedure for sending the baton to the device number n is repeated.

In this way, when no baton is circulated on the communication bus B, the baton is transmitted by itself, and the connected device list 6 is sequentially connected to the device having the response baton. Register the device number (address).

FIG. 4 is a flowchart showing the operation of sending a carrier to the communication bus B when the communication bus control device 10 is newly connected to the communication bus B. The operation at this time is shown in FIG. The operation is similar to that shown in the first few steps of the flowchart of FIG. That is, in FIG. 2, first, the baton confirmation unit 31 detects whether or not the baton is received on the communication bus B within a fixed time. When the baton cannot be detected, the process transitions from step to the operation of the flowchart shown in FIG. On the other hand, when the baton is received, the contents of the connected device list 6 are updated according to the source address in the baton. Next, check the destination address in this baton to see if it is a baton for the device. Since the device has just been newly connected, the destination address is not addressed to the device, and the process proceeds to step, that is, the flowchart shown in FIG.

The baton confirmation unit 31 refers to the connected device list 6 and confirms whether or not its own station address (device number) is registered in this list. If it is registered (“Y”), the process returns from the step to the operation shown in the flowchart of FIG. If it is not registered (“N”), it detects that the baton goes around all the devices and makes a round, and after a certain time, when the next baton is received, the source address is connected. Register in device list 6. By repeating such an operation, when the source address in the baton becomes the device number PRA one before the device in the baton order, the carrier is sent to the communication bus B for a certain period of time.

In this way, the device newly connected to the communication bus B detects the circulating button each time and registers the transmission source address in the connected device list 6, and registers it. When the transmitted source address becomes the previous station address, the carrier is transmitted to the communication bus B.

Now, assuming a system using the device of the present invention, the operation thereof will be specifically described as follows. For example, the maximum number of connectable devices N = 12, the content of the connected device list 6 is [1, 3, 4, 8, 9, 12] (an example in which 6 devices are connected), and When the address MYA is "4", the next station address NXA is "8" and the previous station address PRA is "3".

The device with the device number (own address) “4” uses the communication bus B when the baton comes around to the device during the normal operation, and then the connected device list. 6, the baton is sent to the device having the device number (next station address) “8”.

Here, it is assumed that a device is newly connected to the position of the device number (address) “6” on the communication bus B. When the device number “6” detects the baton, it detects the source address and registers it in the connected device list 6, and generates this list. Then, when the loop of the buttons is detected and the transmission source address becomes the device number "4" (PRA) immediately before the device number "6", the carrier is transmitted on the communication bus B for a certain period of time. Give out.

The device with the device number “4” detects the carrier from the device number “6” at the time of sending the baton, and the device with the device number “4” receives the destination address corresponding to the next address in the baton order. A baton is sent to NXA "5", "6", "7", and when there is a response baton, the device number ("6") is additionally registered in the connected device list 6.

The device of the present invention described above can also be applied to a system 2 in which the communication bus B is duplicated. Further, when the batons are circulated, the modes may be different so that a baton destined for a device on the connected device list and a baton destined for a device not on the connected device list can be distinguished. Furthermore, any device that has detected a carrier that has been continuously transmitted for a certain period of time sends a baton with the device number corresponding to all addresses not registered on the connected device list as its destination address. You may do it.

[0028]

[Effect of device]

 As described above, according to the present invention, it is possible to improve the usage efficiency of a baton-pass type bus, which has conventionally been poorly used due to a non-response baton, without adding a collision detection function or the like. That is, even if a new device is additionally connected, the baton can be sent to this device with a simple configuration, so that the use efficiency of the communication bus can be improved.

[Brief description of drawings]

FIG. 1 is a configuration block diagram showing a communication bus control device of the present invention.

FIG. 2 is a flow chart showing the operation of the device of the present invention.

FIG. 3 is a flowchart showing the operation of the device of the present invention.

FIG. 4 is a flowchart showing the operation of the device of the present invention.

[Explanation of symbols]

 10 communication bus control device 2 receiver 3 reception processing unit 31 baton confirmation unit 32 carrier confirmation unit 4 driver 5 transmission processing unit 51 carrier generation unit 52 baton generation unit 6 connected device list 7 own station address 8 own station baton generation unit B communication Bus controller

Claims (1)

[Scope of utility model registration request] 1. A baton including a source address and a destination address is connected to a communication bus and has a connected device list for registering all devices connected to the communication bus in a list format, In a communication bus control device that obtains the right to use the communication bus when the baton comes around, a baton confirmation unit that updates the connected device list according to the source address and the destination address in the baton, and the baton. From the baton confirmation unit, a local station baton generation unit that detects whether or not the received baton by comparing the destination address and the local station address from the confirmation unit is addressed to the local station, and the baton completes a cycle. Of the destination address, the own station address and the connected device list of When there is no carrier, a carrier generation unit that sends a carrier to the communication bus, a carrier confirmation unit that receives the carrier from another device on the communication bus, and a self-station baton generation unit that does not receive a carrier by the carrier confirmation unit If there is a detection output of the above, if the destination address is added to the baton with reference to the connected device list and there is a carrier reception of the carrier confirmation section and there is a detection output of the own station baton generation section, A communication bus control device, comprising: a baton generator that adds an address not stored in a connected device list to the baton as the destination address and sends the address to the communication bus.