JPS6340941A - Processing system for abnormality of programmable controller - Google Patents

Abstract

PURPOSE:To control the output from a slave station by constituting the titled system so that the slave station stores an abnormality processing program which is transferred from a master station, and its program is executed, when a communication abnormality is detected in the slave station. CONSTITUTION:When an input/output system of a programmable controller 1' starts an operation, an input is inputted to the body 1' through an I/O interface 14, and an input from an input/output equipment 26 is inputted to a slave station 2' through an I/O interface 25 and transferred to the body 1' through a communication line 3 by a communication interface 24. When communication is made impossible due to the cause of a disconnection of the communication line 3, or a fault, etc. of the interface 14, 24 in the course of an operation, a communication abnormality is detected by a communication abnormality detecting device 21-1. subsequently, by using an external input from the equipment 26, which is inputted through the interface 25, and a data in a data memory 23, a program stored in a memory 22 is executed by an arithmetic part 11, and its result is outputted to the outside through the interface 25.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention provides data transfer between a master station programmable controller and a slave station programmable controller as a remote human output slave station located at a remote location via a communication line. The present invention relates to a remote input/output system for a programmable controller that performs the above operations, and particularly to an abnormality handling system for a programmable controller that allows each slave station to individually respond to abnormalities in the communication line.

(Prior Art) In general, as shown in FIG. 3, in a remote turnout system using a programmable controller that transfers data between a master station programmable controller 1 and a slave station programmable controller 2, it is possible to There is an advantage that the remote input/output devices 2 can be distributed and arranged in remote locations.

However, in conventional remote input/output systems for programmable controllers of this type, if communication between the slave station 2 side and the master station 1 is interrupted due to an abnormality in the communication line 3,
Each slave station 2 was unable to send the output from the input/output devices connected to the slave station 2 to the master station 1, and a situation occurred in which the output data to be output to the input/output devices could not be received from the master station 1. .

For this reason, in the input/output system of conventional programmable controllers, from the standpoint of ensuring safety, all outputs from the slave station 2 to the input/output devices are reset (off) or maintained in the state immediately before communication was interrupted. Countermeasures are being considered.

FIG. 4 shows an example of a specific configuration of a conventional personnel output system of this type of programmable controller.

In the programmable controller turnout system shown in FIG. 4, the programmable controller master station l is
Water level setting information from a water level setting switch 1-1, which is an example of a human-powered device, is manually processed.

The arithmetic processing results and control signals are transmitted to the slave station programmable controller 2 via the communication line 3, and the slave station programmable controller 2 transmits the arithmetic processing results and control signals to the external peripheral device 26, 27
29 is a water level detection switch that detects the water level of the water tank 40, 30 is a water supply valve, 31 is a drain valve, and 32 is a heater that warms water.

In the programmable controller system as shown in FIG. 4, when water level A is designated by the water level setting switch 1-1, the programmable controller master station 1 receives water level detection signals from the water level detection switches 27, 28, and 29 of the water tank 40. It is received via the slave station programmable controller 2 and instructs the water supply valve 30 to "open" until the water level reaches A. When the water level reaches water level A, the water supply valve 30 is opened.
The water level of the water tank 40 is controlled as "closed".

Next, as described above, when the programmable controller master station 1 is instructing water supply up to water level A, a communication abnormality occurs in the transmission cable 3, such as a disconnection or a data transmission stoppage of the master station programmable controller 1. If this occurs, the slave station programmable controller 2 will close the water supply valve 3.
Conventional programmable controller systems are configured to either instruct the water supply valve to close immediately or to maintain the state immediately before communication was interrupted.

Therefore, in such a programmable controller system, if a communication abnormality as described above occurs while the water in the water tank 40 is being heated by the heater 32, the water supply valve 30 is kept in the "open" state. Otherwise, the water supply valve 30 will stop supplying water, so if you are not aware of the communication abnormality, water may overflow from the water tank 40 or the water temperature may rise, which is extremely dangerous. be.

Furthermore, even if you notice the above-mentioned communication abnormality and manually close the water supply valve 30 or turn off the power to the heater 32,
Until the transmission cable 3 restores normal communication, the external peripheral device 26 must be operated manually, making it impossible to accurately control the device and making the operation of the external peripheral device 26 complicated.

[Problem that the invention seeks to solve]

In other words, in such a conventional programmable controller remote person output system, the problem is that the slave station cannot control the output to the input/output device in response to changes in the input from the input/output device connected to the slave station. was there.

Therefore, the purpose of the present invention is to solve such problems,
In a programmable controller remote human output system, even if an abnormality occurs in the communication system, the data output from each slave station is not fixed, and the data can be output from the input/output equipment.
An object of the present invention is to provide an abnormality processing method for a programmable controller that can control input/output equipment with the minimum necessary amount according to data input to a slave station.

[Means for solving problems]

In order to achieve such an object, the present invention provides a system for transmitting and receiving data between a slave station programmable controller and a master station programmable controller via a communication line. Prior to this, an error handling program is transferred from the master station to the slave station via a communication line, and the slave station memorizes the transferred error handling program. It is characterized in that when an error is detected, a stored abnormality handling program is executed.

(Function) The present invention provides an abnormality processing program storage memory and program execution means in distributed remote human output slave stations,
At system startup or before system operation, the error processing program for each slave station is transferred from the programmable controller of the master station and stored in this memory.During normal operation, the master station inputs the error processing program for each slave station. Output is controlled, but if a communication error occurs, each slave station executes the above program and controls the output to the input/output equipment connected to the slave station, so there is no risk of system failure. can.

〔Example〕

Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 1 shows an example of the configuration of an embodiment of the present invention.

In FIG. 1, a remote input/output device (slave station) 2° is attached to a programmable controller main body (master station) 1° via a communication line 3.

The programmable controller body 1 includes a sequence calculation execution unit 11 and a memory 1 for storing user programs.
2) A data memory 13, a communication interface 14 with the slave station 2', an I10 interface 15, and a loader interface 16 are provided, and the loader 4 is attached to the loader interface 16 as required.

The slave station 2' includes a sequence calculation processing unit 21, a slave station program storage memory 22) data memory 23, and a communication interface 2 with the programmable controller main body 1'.
4. An I10 interface 25 and a communication abnormality detection device 21-1 are provided.

In such a configuration, a user of the programmable controller system connects the loader 4 to the programmable controller main body 1' and writes a sequence program into the memory 12. Also, at this time, the master station 1' and the slave station 2
Similarly, the abnormality processing program ' is also written in the storage area of the memory 12 as shown in FIG.

After completing the program input, when the user operates the loader 4 to instruct the program input to be completed, the programmable controller main body 1' transfers the communication error program to each slave station 2' from the communication interface 14 via the communication line 3. , the transferred programs are stored in the program memory 22 of each slave station 2'.

When the programmable controller's turnout system starts operating, the input connected to the programmable controller main body 1' is taken into the programmable controller main body 1' through the I10 interface 15,
In addition, input from the input/output device 26 connected to each slave station 2' is taken into the slave station 2' through the I10 interface 25, and is transferred to the programmable controller main body 1' via the communication line 3 by the communication interface 24. Ru.

This human power data is taken into the programmable controller main body 1' through the communication interface 14, and the calculation section 11 in the programmable controller main body 1' processes the future human power data, the human power data from the input/output device W1-1, and other data stored in the memory 12. Perform sequence operations on data.

The output data resulting from the calculation is output to the external input/output device 1-1 through the I10 interface 5, and the output data for each slave station 2' is output to the communication interface 14.
As a result, the data is transferred to the slave station 2' in the opposite direction to the input data described above, and is output to the external input/output device 26.

At this time, data necessary for calculation when a communication abnormality occurs in the data memory 13, such as data manually input from the input/output device 1-1 to the programmable controller main body 1', is also sent to each slave station 2 at the same time.

If communication becomes impossible during system operation due to a disconnection of the communication line 3 or a failure of the communication interface 14.24, a communication abnormality detection device 21 detects a parity error or frame error in the communication information. -1
detects a communication abnormality and connects the I10 interface 2.
The calculation section 21 executes the program stored in the memory 22 using external human power from the input/output device 26 and other data in the data memory 23, which are taken in through the input/output device 5, and outputs the calculation results to the outside through the I10 interface 25. do.

At this time, in the programmable controller main body 1', the arithmetic unit 11 executes the communication abnormality processing program stored in the memory 12 and outputs the result.

In the embodiment of the present invention, the program for each slave station 2' is transferred to the slave station according to instructions from the loader 4, but the program may also be transferred when the power is turned on.
Alternatively, a switch may be provided in the programmable controller body 1', and the program may be transferred by operating the switch.

Further, at the same time as writing the program for slave station 2° into the master station 1°, the corresponding program may also be written into the slave station 2'.

Furthermore, the program memory 12 may not have a program area for each slave station 2', and the program memory 22 of each slave station 2' may be written directly through the communication line 3 by the loader 4 connected to the programmable controller body 1. Needless to say.

〔Effect of the invention〕

As described above, according to the present invention, each remote slave station of a programmable controller can also execute a user program, and even if an abnormality occurs in the communication system, the user program can be executed in response to input to each slave station. This makes it possible to control the output from the slave stations, preventing the danger of fixed outputs to the input/output devices connected to the slave stations, and storing the programs of each slave station in the master station. Since there is no need to provide a loader interface section in the slave station, it is possible to provide a programmable controller turnout system that is cheaper than a conventional inter-programmable controller link system in which programmable controller master stations are linked.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an example of a configuration in an embodiment of the present invention; FIG. 2 is an explanatory diagram showing a storage area of the memory 12 shown in FIG. 1; FIG. 3 is a block diagram showing an example of a conventional configuration; FIG. 4 is a block diagram showing an example of a specific configuration of a conventional example. 1.1'...Programmable controller master station, 1-
1...I/O equipment, 2.2'...Programmable controller slave station, 3.
... Communication line, 4... Loader, 11, 21... Arithmetic execution unit, 12) 22... Program memory, 13.23... Data memory, 14, 24... Communication interface, 15. 25・
... I10 interface, 16... Loader interface, -21-1... Communication abnormality detection device, 26... Input/output device, 27-29... Water level sensor, 30... Water supply valve, 31. ...Drain valve, 32...Heater, 40...Water tank. O→Koakejitsusha Example Pro 4.7ri 2 Figure 1 Figure 2

Claims (1)

[Claims] 1) In a system in which data is exchanged between a slave station programmable controller and a master station programmable controller via a communication line, prior to exchanging data with the master station: , an abnormality handling program is transferred from the master station to the slave station via the communication line, the slave station stores the transferred abnormality handling program, and when the communication abnormality occurs in the slave station, A programmable controller abnormality handling method characterized in that when detected, the stored abnormality handling program is executed. 2) In the programmable controller abnormality processing method according to claim 1, either of the following: and when the abnormality processing program is input to the master station, the master station transfers the abnormality processing program to the A programmable controller abnormality processing method characterized by transferring data to a slave station.