JPH0272411A - Programmable controller system - Google Patents

Abstract

PURPOSE:To attain a fixed transmission cycle of data by holding the total I/O data on a system also via a remote I/O device itself. CONSTITUTION:For a programmable controller main body 1 and each remote I/O device 3, the overall switch states of the input and output devices of a programmable controller system are stored in the I/O data memories A and D. Therefore the device 3 can easily recognize the contents of the necessary switch states of other remote I/O devices by having an access to the memory D of its own device. Thus it is not required to make the controller main body 1 confirm the data contents every time such a request is produced. Then the process is simplified for a programmable controller system. Furthermore the communication cycle is always fixed since each remote I/O device can refresh the contents of the memory D.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of the Invention] The present invention relates to a programmable controller system having a remote input/output device (hereinafter referred to as remote 1/○ device).

[Prior Art] Conventionally, in a system configured by connecting a plurality of remote I/O devices to one programmable controller, each remote I/O device has an input/output device such as a photoelectric switch or a proximity switch. Input devices and output devices such as relays and solenoids are connected. The main body of the programmable controller has a ■/○ data memo that maintains the switch status of the input/output devices connected to each remote input/output device, but each remote input/output device has only the input/output devices connected to it. A memory having switch states is provided. The programmable controller main body periodically sends data of the output device to each remote I/O device, and is configured to transmit data on the switch state of the input device to the programmable controller main body.

[Problem to be solved by the invention]

However, in such conventional systems, if you try to determine the status of input/output devices connected to the programmable controller main body or other remote I/O devices in the system from a certain remote I/O device, The periodic data transmission cycle will change. In addition, since the programmable controller itself is equipped with a memory that holds the input/output data of all remote I/O devices, the remote ZIO device can be connected to other remote I/O devices via the programmable controller itself. It has the disadvantage that it requires data communication, resulting in an excessive load.

The present invention has been made in view of the problems of the conventional programmable controller system, and each remote I/O device is configured to input/output data from other remote I/O devices whenever necessary. There is no need to access the programmable controller at any time, and the technical challenge is to make the data transmission cycle constant.

[Structure and effects of the invention]

(Means for Solving the Problems) The present invention includes a programmable controller main body 1 and a plurality of remote I/O devices 3 to N connected to the programmable controller main body via transmission lines 2. and a programmable controller system that controls input/output devices connected to a remote I/O device, as shown in FIG. I/O data memory A that holds switch states of input/output devices
, a data transmission means B that sequentially sends the output data of each output device to each remote I/O device and receives input data of each input device, and is connected to the input data obtained from the data transmission means and the programmable controller. and a data updating means C for updating the I/O data memory with the input data of the input device and updating the output data of each output device according to a predetermined program, and each remote I/OW location has the following: I/O that maintains the switch status of input/output devices connected to each remote I/O device including the programmable controller main body
The data memory D periodically sends the data of the input device of the own device to the programmable controller main body,
data transmission means E for receiving data from the output device;
The output data obtained from the O data memory is output to the output device of the own device, and the data of the input device within the own device is output to the I
The data update means F stores data in the /O memory.

(Operation) According to the present invention having such features, the switch states of the entire input device and output device of the programmable controller system are stored in the I/O data memory of the programmable controller main body and each remote I/O device, respectively. remembered. Then, the programmable controller main body updates the data in the I/O data memory with the input data of the input device obtained from the input device of the own device and the data transmission means, and updates the output data by performing predetermined processing. ing.

Also, each I/O device maintains the switch status of not only the input/output devices connected to itself but also the input/output devices of the entire system, and its contents are changed based on the input data obtained from the input device. The output device of the device itself is driven based on the output data that is updated and given via the transmission line. The update is performed at predetermined intervals to match the data in each I/O data memory.

(Effects of the Invention) Therefore, according to the present invention, not only the programmable controller main body but also each remote I/O device internally controls the switch status of the input/output device of another remote I/O device when the switch state of the input/output device of another remote I/O device is required. By accessing the I/O data memory of , the contents can be easily recognized. Therefore, it is no longer necessary to check the data contents in the programmable controller main body every time such a request occurs, and the effect of simplifying the processing can be obtained. Furthermore, since each remote I/O device always refreshes the contents of the I/O data memory, the communication cycle is always constant.

[Explanation of Examples]

FIG. 2 is a diagram showing the overall configuration of a programmable controller system according to an embodiment of the present invention. In this figure, a programmable controller main body 1 is connected to a plurality of remote I/O devices 3, 4-. ...-N
is connected. The programmable controller main body l and remote I/O devices 3 to N have input/output devices 1a to Na, respectively.
is connected. Here, the input device is, for example, a photoelectric switch or a proximity switch, and the output device is, for example, a relay, an actuator, or the like. The programmable controller main body 1 performs a series of controls by operating each output device based on the switch states of the input devices connected to the main body and the input/output devices connected to each remote I/O device 3 to N. This is what we do.

A monitor device 6 can be optionally connected to the programmable controller main body 1 or each remote I/O device. The monitor device 6 is for checking the operating status of the programmable controller main body 1 and the remote I/O'W1i3 to N.

As shown in FIG. 3, the programmable controller main body 1 has a CPUI 1, and the CPUI/O has a read-only memory (hereinafter referred to as ROM) 13. which stores processing programs via a path line 12. A random access memory (hereinafter referred to as RAM) 14 having areas for user programs and I/O execution data memory is connected, and an I/O data memory 16 (A) which is a shared memory is connected via an access arbitration circuit 15. Ru. As shown in FIG. 4, the I/O data memory 16 stores the output data of the programmable controller main body, the remote
This is a table-type memory that includes an area for storing output data of N, an area for storing all input data of the programmable controller main body, and input data of each remote ■/O device, and is shared with the data communication section 20. An access arbitration circuit 15 is provided. In addition, the pass line 12 has an input cover sofa circuit 17 and an output cover sofa circuit 1.
8 is connected. A photoelectric switch and a proximity switch (not shown) are connected to the inlet sofa circuit 17. Further, a relay and an actuator (not shown) are connected to the output cover sofa circuit 18. Now, a monitor control interface circuit 19 is further connected to the pass line 12. Furthermore, the programmable controller body has remote I/O devices 3~
A data communication unit 2o for performing data communication with N is connected. The data communication unit 20 includes a communication-dedicated CPU 21 connected to the path line 12, and a ROM 22.0 that stores a communication program. RAM2 that includes a communication buffer that temporarily holds communication contents and switch states of input/output devices
3 and a communication control circuit 24 are connected thereto. Here, the I/O execution data memory and communication buffer of the programmable controller main body 1 have the same configuration as the I/O data memory 16 shown in FIG. An area for storing input/output data of devices 3 to N is provided.

Next, each remote I/O device is provided with a CPU 31 as shown in FIG. Connected.

Also, like the programmable controller main body, an input Hanofa circuit 35 and an output buffer circuit 36 are connected, and a monitor control interface 37 used when connecting the monitor device 6 is also connected.

Furthermore, the remote I/O device has a communication control circuit 38, and is connected to the programmable controller main body 1 via a transmission line A2. Here, the I/O data memory 34
As shown in FIG. 4, it has the same configuration as the I/O module 16 in the programmable controller main body 1.

Next, the operation of this embodiment will be explained with reference to flowchart 1. FIG. 6 is a flowchart showing the operation of the programmable controller main body 1. In the figure, when the power is turned on, the CPU first performs initial processing such as clearing all memories in step 41 and recognizing the status indicating the connection status of the input/output devices connected to the main body. The process then proceeds to step 42, where a command for reading the status of the input/output devices connected to each of the remote I/O devices 3 to N is sent to the data communication section 20.

The process waits for successive results, and if the results are obtained, the process proceeds to step 44 to create a table in the I/O data memory 16 as shown in FIG. Then, the process advances to step 45 to perform input/output glue refreshing.

This reads data from the input vanofer circuit 17 of the programmable controller main body 1 and outputs it to the I/O in RAMI4.
This is a process of storing the output data in the execution data memory and outputting the output data in the I/O execution data memory to the outside via the output sofa circuit 18.

Then, the process proceeds to step 46, where a flag is set to indicate that the I/O data memory 16, which is a shared memory, is BUSY, and the process proceeds to step 47, where the output data of the I/O execution data memory and the input data of the programmable controller main body 1 are set as BUSY.
Data is exchanged by transferring input data of each remote I/O device in the I/O data memory to the I/O execution data memory.

Then, the process proceeds to step 48 to reset the BUSY flag, and the process proceeds to step 49 to start communication.

The process then proceeds to step 50 to execute the instructions of the user program, and returns to step 45 to repeat the same process. Here, the CPU 1 updates the data in the ■/○ data memory with the input data in steps 45 to 50, and also functions as a data updating means C that updates the output data of each output device according to a predetermined program.

On the other hand, when the power is turned on, the CPU 21 of the data communication section 20
First, in step 51, initial processing such as clearing the memory is performed, and the process proceeds to step 52, where it waits for a status read command from the CPU 1. If this command is obtained, the process proceeds to step 53, where each remote I/O
Status inquiries are sequentially made to O devices 3 to N. Then, the results obtained from each remote I/O device are C1・t
Complete the table according to step 44 described above in the CPU II by transferring to I/O. Then, it waits for the completion of the table (step 54), and when the table is completed, in step 55, each remote) 1/○ device 3
-N, the created I/O data memory table is sent sequentially. The CPU II then proceeds to step 56 and waits for a command to start communication, and if the CPU II proceeds to step 49 and sends a command to start communication, it proceeds to step 57 and waits for a command to start communication.
Check if USY flag is set. If this flag is set, CPUI 1 is the I/O
Since the data memory 16 is being accessed, wait for this flag to be reset, and if it is reset, proceed to step 58 and connect the I/O data memory 16 and data communication unit 2.
Converts data to and from communication buffer 0.

Then, proceed to step 59 to connect each remote) I/O device 3 to
Send output data to N. Then, the process proceeds to step 60, and the transmission right is transferred to the nearest Spider-1-I/O0 device 3. In this way, the remote I/O device 3 will transmit its input data, as will be described later. Therefore step 6
In step 1, input data is received from each remote I/O device, and the process proceeds to step 62, where the input data is received from the final remote I/O device N.
Check whether data reception is complete.

Continue receiving data until complete step 61.6
2) When data reception is completed, the process proceeds from step 62 to step 57 and the same process is repeated. Here CPU2
1 achieves the function of data transmission means B which sequentially sends output data to each remote I/O device in steps 51 to 62 and receives data from an input device.

On the other hand, as shown in FIG. 7(a), when the remote I/O device is powered on, it performs initial processing such as memory clearing (step 71), and then proceeds to step 72 to
It identifies the status of the input/output device (I/O status) in the O0 device and sends this information in response to a status command from the programmable controller main body l. Then, in step 73, the I/O status of the entire system obtained from the main body is received, and the same table as that of the programmable controller main body 1 is created in the I/O data memory 34. Then, in step 74, the input/output devices within the own device are refreshed. That is, its remote I/O0
The switch state of the input device in the device is input, the received output data of the I/O data memory is outputted to the output device, the process is completed, and the same process is repeated thereafter.

Now, if there is an interrupt via the transmission A2, the cause of the interrupt is analyzed in step 75 as shown in FIG. The data is stored in 34 and the processing is completed. If the right to transmit data is granted due to an interrupt factor, in step 79 only the input data of the remote I/O device in the I/O data memory is sent to the programmable controller main body 1. Then, proceed to step 80 and transfer the transmission right to the remote I of the next address.
/O Send to the device and end the process. Here CPtJ3
1 achieves the function of data updating means F that outputs the output data of the I/O data memory to the output device in step 74 and stores the input data in the own device in the I/O data memory 34, 76 to 79 achieve the function of data transmission means E for transmitting the input data of the own device to the programmable controller main body 1 and receiving the output data of each output device.

FIG. 8 is a flowchart showing the processing when the monitor device 6 is connected to the programmable controller main body or each remote I/O device and a request for monitoring is made. If there is a request for monitoring, the process proceeds from steps 91 to 92 to read the address of the requested input/output device from the I/O data memory connected to each device. Then, on/off display is performed based on the data (step 93).
Finish processing. The monitor device 6 can monitor the switch states of necessary input/output devices on the spot by connecting not only the programmable controller main body 1 but also any remote I/O device.

In this way, the I/O data of the entire system will be held in the remote/O device itself, and the data will be transferred not only to the programmable controller main body but also to all the remote ■/O devices in a predetermined cycle.

It will be held in the device. Therefore each remote I/O
Even when a device needs data from another remote I/O device, it can obtain that data by accessing its own internal memory. Therefore, when such a factor occurs, there is no need to request data from other remote I/O devices via the transmission line one by one, and the processing in that case can be speeded up. Furthermore, the effect that the amount of data communication is constant and the cycle time does not change can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the functional configuration of the programmable controller system according to the present invention, FIG. 2 is a block diagram showing the overall configuration of the programmable controller system of this embodiment, and FIG. 3 is a block diagram showing the configuration of the programmable controller main body. 4 is a diagram showing the contents of the I/O data memory, FIG. 5 is a block diagram showing the configuration of the remote I/O device, FIG. 6 is a flowchart showing the operation of the programmable controller main body, and FIG. a). FIG. 7 (bl is a flowchart showing the operation of each remote I/O device, and FIG. 8 is a flowchart showing the operation of the monitor device. A, D -------1/O data memory B
, E---- Data transmission means C, F-----
Data update means 1---Programmable controller body 2...Transmission line 3.4~N---Remote I/O device 6---Monitor device I/O, 21.31
・-・-CPU 14.23--RAM 16
．． 34.--I/O data memory 23.38--
Communication control circuit 17.35-・-human cover sofa circuit
I8.36---Output basso circuit patent applicant Tateishi Electric Co., Ltd. Agent Patent attorney Kanki Okamoto (and 1 other person) Ward ^) r) C)

Claims (1)

[Claims] (1) It has a programmable controller main body and a plurality of remote input/output devices (hereinafter referred to as remote I/O devices) connected to the programmable controller main body via transmission lines, and the programmable controller main body and remote I/O devices In a programmable controller system that controls input/output devices connected to the programmable controller main body, the programmable controller main body is an I/O controller that maintains switch states of the input/output devices connected to each remote I/O device including the programmable controller main body. a data memory; a data transmission means for sequentially transmitting output data of each output device to each remote I/O device and receiving input data of each input device; and input data obtained from the data transmission means and a programmable controller. data updating means for updating the I/O data memory with input data from an input device connected to the remote I/O device and updating output data from each output device according to a predetermined program; The device includes an I/O data memory that retains switch states of input/output devices connected to each remote I/O device including the programmable controller main body, and a data memory for periodically transmitting data of the input device of the own device to the programmable controller main body. a data transmission means for transmitting data from the input device and receiving data from the output device; A programmable controller system comprising: data updating means for storing in memory; and a programmable controller system.