JPH0670380A - Remote controller - Google Patents

Abstract

PURPOSE:To execute the communication by supervising a communication state of the operating side on the standby side so as to select the standby side to be the operating side when the operating side becomes a communication abnormality thereby controlling data transmission reception in a remote input output unit. CONSTITUTION:Even when a remote input output station control card 7a on the active side becomes a communication abnormality the communication with a programmable controller main body is implemented by a remote input output station control card 7b on the standby side smoothly to continue the control of a process input output device 15.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a remote controller having a remote input / output section.

[0002]

2. Description of the Related Art Since a remote device may not be able to be immediately maintained in the event of a failure, many devices are devised so that the system does not go down due to a dual system. FIG. 4 is also an example thereof, in which two remote input / output station control cards 7a and 7b are provided in the remote I / O input / output unit 6 and one is used as an operating system and the other is used as a standby system to control the process input / output device. ing. When there is an abnormality in the operating system, the device operated by the switching card 21 is switched to the standby system.

However, since this device requires an independent switching card 21, there are various inconveniences, and the device of FIG. 5 has been proposed to solve this problem.

FIG. 5 shows a remote input / output station control card 7 in the remote I / O input / output unit 6.
FIG. 3 is a diagram showing a system configuration when a and 7 b are duplicated in an operating system and a standby system, in which a programmable controller main body 1 and a remote I / O input / output unit 6 are connected via a bus 5.

In the programmable controller body 1, a programmable controller CPU section 2 and a remote I / O master station 3 are connected by a bus 4. Then, the remote I / O master station 3 exchanges signals with the bus 5.

The remote I / O input / output unit 6 includes remote input / output station control cards 7a and 7
b, it is composed of a plurality of process input / output devices 15. Remote I / O station control card 7
Each of a and 7b includes a transmission / reception unit 8, a control unit 9, an operation / standby monitoring unit 10, and a process device I / F unit 12, which are interconnected by a bus 13.

The remote input / output station control cards 7a and 7b monitor their mutual operations by connecting the operation / standby monitoring units 10 to each other via a bus 11. Also, the remote I / O control card 7
The a and 7b and the process input / output device 15 are connected by the bus 14, and the connection is made via the process device I / F unit 12.

Next, the operation will be described. Programmable controller C of programmable controller body 1
The PU unit 2 executes control by a program included therein, and performs data transfer between the remote I / O master station 3 of the programmable controller main body 1 and the transmission / reception unit 8 in the remote input / output station control cards 7a and 7b.

The data transferred to the remote input / output unit 6 is further transferred to the process input / output device 15 via the process device I / F section 12 in the remote input / output station control card 7.

Of the remote input / output station control cards 7a and 7b, for example, the one set on the driving side is used.
The state of "a" is monitored via the operation / standby monitoring unit 10 in the card 7b on the standby side, and is switched to the standby side when an abnormality occurs. After that, data is exchanged with the process input / output device 15 in the remote input / output unit 6 and communication with the bus 5 is performed.

[0011]

However, in the conventional device, only the driving / standby monitoring section monitors the state between the driving side and the standby side, and the driving side outputs the signal indicating the normal state to the bus. When a communication error occurs, there is a problem that communication between the remote input / output unit and the programmable controller main body is disabled and the process input / output device cannot be controlled.

The present invention has been made in order to solve the above problems, and by monitoring the communication state of the driving side on the standby side, even if the driving side has a communication error, the standby side can operate as the driving side. The purpose is to switch and control data exchange in the remote input / output unit and execute communication.

[0013]

The device according to the present invention is a means for checking the transmission state of the driver side when the control circuit of the remote input / output station control card is on the standby side and the driver side has an abnormality. The output station control card is equipped with a means for switching to the driving side and continuing communication, a monitoring means for the standby side to monitor the communication state of the driving side, and an operation for switching the standby side to the driving side when there is a communication error on the driving side. And a switching means.

[0014]

According to the apparatus of the present invention, even when the remote input / output station control card 7a on the driving side has an abnormal communication, the remote input / output station control card 7b on the standby side can smoothly communicate with the programmable controller main body 1. Then, the control of the process input / output device 15 can be continued.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to the drawings. The same symbols are used for the same or corresponding portions as in the conventional example. In FIG. 1, 16 is a control microcomputer (control μ-P) that controls the remote input / output station control cards 7a and 7b, and 17 is an operation / standby that performs standby state monitoring control between the remote input / output station control cards 7a and 7b. It is a monitoring control unit.

Next, the operation will be described. If the operating side is the remote input / output station control card 7a, the control microcomputer (μ-P) 1 inside the standby side remote input / output station control card 7b
Reference numeral 6 monitors the communication state of the driver side remote input / output station control card 7a via the bus 5.

Control microcomputer 16 for monitoring
2 shows a monitoring control flow of the standby side remote input / output station control card when the transmission right is transferred to the driving side remote input / output station control card 7a and the transmission is not performed even after a certain time elapses. 7b switches the operating / standby state between the remote input / output station control cards to communicate with the bus 5. This switching is performed via the bus 13.

That is, in step 100 of FIG. 2, whether or not it is the transmission order of the own unit is judged by whether or not the transmission right is given, and if it is the transmission order of the own unit, as shown in step 101. The standby side remote input / output station control card 7b is the driving side remote input / output station control card 7
Monitor the transmission of a.

If it is determined in step 102 that the remote input / output station control card 7a on the driving side is normally transmitting, monitoring is continued as shown in step 103, and the process returns to step 100.

If it is not determined in step 102 that normal transmission has been performed, the operation system is switched as shown in step 104. That is, the remote input / output station control card 7 that has been on the driving side until now.
a becomes the standby side, and the remote input / output station control card 7b, which has been the standby side until now, is switched to the driving side.

Then, as shown in step 105, data is transmitted from the remote input / output station control card 7b, and as shown in step 106, the control within the remote I / O unit is performed.

In the first embodiment, the switching of the remote input / output station control cards 7a and 7b shown in FIG. 1 at the time of duplication has been described. As a second embodiment, the remote I / O master station 3 in FIG. 5 is shown in FIG. As shown in the figure, it may be possible to adopt a dual structure. At this time, the same effect can be obtained by adding the function of the flow shown in FIG. 2 to the remote I / O master station 3.

[0023]

As described above, according to the present invention, the remote I / O station control card is duplicated,
Equipped with a function to monitor the communication state of the driving side on the standby side,
When there is an abnormality on the driving side, the standby side continues communication instead of the driving side, which has the effect that a highly reliable remote input / output device can be configured.

[Brief description of drawings]

FIG. 1 is a block diagram of an apparatus showing a first embodiment of the present invention.

FIG. 2 is a flowchart showing a control processing state of a control microcomputer in FIG.

FIG. 3 is a block diagram of an apparatus showing Embodiment 2 of the present invention.

FIG. 4 is a block diagram showing an example of a conventional device.

FIG. 5 is a block diagram showing an improved example of a conventional device.

[Explanation of symbols]

1 Programmable controller main unit 2 Programmable controller CPU unit 3 Remote I / O master station 4 Bus inside remote I / O main unit 5 Bus between remote I / O master station and remote I / O station control card 6 Remote I / O input / output unit 7 Remote I / O station control card 8 Transmitter / receiver unit 9 Control unit 10 Operation / standby monitoring unit 11 Bus between remote I / O station control cards in remote I / O I / O unit 12 Process device I / F unit 13 Remote I / O station control Bus in card 14 Bus in remote I / O input / output unit 15 Process input / output device 16 Control microprocessor (μ-P) 17 Operation / standby monitoring controller

Claims (1)

[Claims] 1. A remote controller comprising a remote input / output unit which is connected to a controller main unit via a transmission line and is installed at a remote place, and which has a redundant communication function and unit control function, and communication on the operating side. A remote controller comprising: a monitoring unit that monitors a state on the standby side; and an operation switching unit that switches the standby side to the driving side when the monitoring unit detects a communication abnormality on the driving side.