JPH02263205A - Programmable controller remote I/O device - Google Patents

Abstract

PURPOSE:To easily specify a remote I/O device having abnormality by confirming this abnormality by outputting a confirming signal to the I/O device from a CPU device and by confirming the abnormality of the remote I/O device with deciding whether an answer signal is received or not. CONSTITUTION:A buffer 72 is turned off when a switch 11 is closed together with buffers 73 and 79 turned on respectively. Thus the confirming signal inputted from a CPU device via a flip-flop 6 is inputted to a counter 78 via the buffer 73 and an inverter 75. A shift register 77 which is actuated by a clock signal is connected to the counter 78, and an answer signal is outputted via the buffer 79 when a prescribed time passed. Therefore an answer signal output circuit works as long as a normal working state is kept when the CPU device outputs a confirming signal for confirmation of the working of a remote I/O device. Thus the answer signal output circuit sends the answer signal back to the CPU device. As a result, a device having abnormality is easily discriminated and therefore the system down time can be shortened at occurrence of the abnormality.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a remote I10 device for a programmable controller that can respond to inquiries about operational abnormalities from a CPU device.

(Summary of the Invention) The present invention provides, when a confirmation signal output from a CPU device is input to confirm the operation of a remote I10 device, a response signal indicating that the remote I10 device is operating normally. By equipping the remote I10 device with a response signal output circuit that outputs the response signal as an input signal to the CPU device, it is possible to easily identify a remote I10 device in which a communication abnormality has occurred and exclude it from the communication system.

(Prior art and its problems) Conventionally, in the remote 11 device of a programmable controller, when a communication abnormality occurs during communication processing with the CPU device, the remote I10 device is excluded from the communication system, and the remaining normal operation is canceled. Communication with the remote I10 device has been resumed.

However, when a communication abnormality occurs, it may not be easy for the user to determine which remote I10 device is abnormal, and it may take time to find the abnormal device.
The problem of prolonged system downtime is often encountered.

(Object of the Invention) This invention was made to solve the above problems, and its purpose is to provide a programmable controller in which a CPU device can easily identify a remote I10 device in which an abnormality has occurred. The purpose of the present invention is to provide a remote I10 device.

(Structure and Effects of the Invention) In order to achieve the above object, the present invention provides a remote I1
0 When a confirmation signal output from the CPU device is input to confirm the operation of the device, a response that outputs a response signal indicating that the device is operating normally as an input signal to the CPU device. It is characterized by having a signal output circuit.

With this configuration, in this invention, the CPU
When the device outputs a confirmation signal to confirm the operation of the remote I10 device, if the remote I10 device that received the confirmation signal is operating normally, the response signal output circuit is activated and the response signal is sent to the CPU. By returning the information to the device, the remote I10 device in which the abnormality has occurred can be easily identified and promptly removed from the communication system. As a result, system down time when an abnormality occurs can be reduced.

(Example) Next, embodiments of the present invention will be described based on the drawings.

FIG. 1 is a block diagram showing a schematic configuration of a remote I10 device of a programmable controller according to an embodiment.

This remote I10 device has connector 1. MPU (central processing unit) 5, which is the center of overall control, and M
Input interface controlled by PU52. Output interface 8. Buffer 4. It is composed of a flip-flop 6, a switching flip-flop 7, and a communication interface transcoder 10 that complies with the R5-485 standard.

FIG. 2 is a circuit diagram specifically showing the configuration of the switching flip-flop 7, which is a response signal output circuit.

In the figure, the switch 11 is switched depending on whether or not the CPU device (not shown) performs processing for checking the operation of the remote I10 device, and is closed in advance when checking for abnormal operation.

When the switch 11 is closed, the buffer 72 is turned on, and the FF1 buffers 73 and 79 are turned on, and the confirmation signal input from the CPU device via the flip-flop 6 passes through the buffer 73 and is input to the counter 78 via the inverter 75. A shift register 77 operated by a clock signal is connected to the counter 78, so that a response signal is outputted via a buffer 79 after a predetermined period of time has elapsed.

The confirmation signal input from the CPU device is emitted when executing the communication abnormality diagnosis process written in the user program, and if the remote I10 device that received the confirmation signal is operating normally. Due to the operation of the switching flip-flop 7 described above, a response signal is returned to the CPU device, confirming that it is operating normally.

If the remote I10 device is out of order, the operation of the device, including the operation of the switching flip-flop 7 described above, will stop or become abnormal and no response signal will be output, so the CPU device will It is assumed that a failure has occurred, and further communication regarding this device can be stopped.

Further, if the communication abnormality diagnosis process is not executed between the CPU device and the remote I10 device, the switch 11 is opened;
The buffer 72 is turned on, the buffers 73 and 79 are turned off, and the confirmation signal input via the flip-flop 6 passes through the buffer 72 and reaches the output interface 8. In other words, when communication abnormality diagnosis processing is not performed, the signal that should originally be a confirmation signal input through the flip-flop 6 can be made into a normal output signal, allowing efficient use of the remote I10 device and It is extensible.

FIG. 3 is the I10 memory map of this device.

In the figure, the response signal is the most significant bit of the input channel n, which has a 16-bit configuration, and the response signal is the most significant bit of the input n channel, which also has a 16-bit configuration.
+1) A confirmation signal is assigned to the most significant bit of the channel. These most significant bits are used as normal human output signals when communication abnormality diagnosis processing is not performed.

As described above, in this embodiment, when executing communication abnormality diagnosis processing, a confirmation signal is sent from the CPU device to the remote I10.
It becomes easy to confirm an abnormality in the remote I10 device by outputting the signal to the device and checking whether a response signal is returned.

Furthermore, if the communication abnormality diagnosis process is not to be executed, the switch 11 can be changed to output the confirmation signal as a normal output signal, thereby providing an easy-to-use and efficient remote interface.
10 devices can be realized.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a schematic configuration of a remote I10 device according to an embodiment of the present invention, FIG. 2 is a circuit diagram showing the configuration of a switching flip-flop, and FIG. 3 is an I10 memory map of the device. 1... Connector 2... Input interface 4... Buffer 5... MPU 6... Flip-flop 7... Switching flip-flop 8... Output interface 9... Communication interface 10...・Transcoder 11...Switch 71.75...Inverter 72.73, 76.79...Buffer 77...Shift register 78...Counter

Claims (1)

[Claims] 1.CPU to check the operation of remote I/O device
When the confirmation signal output from the device is input, the CP sends a response signal indicating that the device is operating normally.
A remote I/O device for a programmable controller, comprising a response signal output circuit that outputs as an input signal to a U device.