JPH11143784A - Display for programmable controller - Google Patents

Abstract

(57) [Summary] When a memory content of a programmable controller is destroyed by electromagnetic noise or the like in a factory, the failure is found and repaired. SOLUTION: The same PLC backup data as the PLC data recorded in the memory of a programmable controller 2 is stored in a programmable controller backup memory 15 (16) in a display device 1, and the programmable controller backup memory 15 (16) is used when the power is turned on. 2-side PLC
Compare the data with the PLC backup data,
If they do not match, the PLC backup data of the mismatched portion is transferred to the programmable controller 2 and repaired.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display device for monitoring a programmable controller (hereinafter, PLC).

[0002]

2. Description of the Related Art In recent years, PLCs used in factories and the like store a lot of important information, such as failure history and the number of shipments, in their internal memories.
The data of the system control program stored in the C memory is also becoming more and more complicated.

On the other hand, in a factory environment, a variety of devices such as a servomotor, an inverter, and a high-voltage power device are connected to a PLC. Destruction of content is more likely to occur.

When the memory contents in the PLC are destroyed,
The PLC stores a lot of such complex data that is important, and the repair work requires a lot of risk and labor. Also, in order to execute the repair work, it is necessary to connect a tool such as a personal computer for transferring / transmitting the program to / from the PLC main body. However, since the PLC main body is generally installed at the back of the control panel, the connection is required. Is not easy.

Conventionally, in order to check for destruction of memory contents in a PLC, a sum value of a memory is calculated in a PLC, and when this sum value matches a reference sum value,
"No destruction"; if they do not match, it is determined that there is "destruction". "Sum value verification" is performed. Things are going on.

[0006]

However, in the above-mentioned conventional "sum value collation", memory corruption may not be recognized. In other words, if the destruction situation is such that the sum value of the destructed memory becomes equal to the reference sum value, it cannot be recognized as a memory destruction.In this case, the system is operated with the destructed data, In some cases, a serious problem of destroying peripheral systems occurred.

[0007] Further, even if memory corruption is found, the repair work performed by connecting a tool to the PLC body at the back of the control panel is not easy, and it requires a great deal of risk and labor to proceed carefully. .

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and an important part of the memory content of a PLC is backed up on a display device for a PLC, which is unlikely to cause memory destruction. An object of the present invention is to provide a display device for a programmable controller that can quickly correct the contents of a memory.

[0009]

According to a first aspect of the present invention, there is provided a programmable controller for storing the same PLC backup data as the PLC data recorded in a memory of the programmable controller. The backup memory is compared with the PLC backup data and the PLC data, and the PLC
When the backup data and the PLC data do not match, the PLC backup data of the mismatched portion is transferred to the programmable controller and
A comparison operation controller for rewriting and restoring a portion where data has become inconsistent.

According to a second aspect of the present invention, in the first aspect of the present invention, the comparison and collation operation of the comparison operation controller is started at an arbitrary timing such as when the power is turned on or at regular time intervals. The time can be set.

The invention according to claim 3 is the PLC according to claim 1, wherein the PLC is obtained by comparison and collation by the comparison operation controller.
The mismatch between the backup data and the PLC data
It is displayed on a display screen.

According to a fourth aspect of the present invention, in the first aspect of the present invention, the PLC data recorded in the memory of the programmable controller is arbitrarily set, downloaded, and stored in the programmable controller backup memory. I do.

According to a fifth aspect of the present invention, in the first aspect of the present invention, as a result of the comparison and collation by the comparison operation controller, the PL
When the C backup data and the PLC data do not match, the repaired portion of the memory of the programmable controller, the mismatch data, and the comparison / collation date and time are written to the memory as log data.

Since the PLC backup data backed up in the display device is hardly affected by harmful noises and electromagnetic fields and is maintained in a normal state, the PLC data is stored in a PLC.
By comparing with the C backup data, the destruction of the PLC data can be reliably detected, and the PLC data can be restored using the PLC backup data.

The PLC data according to the present invention is defined as data stored in a memory of the PLC, such as a user program, which keeps a constant value during operation of the PLC without changing the value. Refers to data.

The programmable controller backup memory according to the present invention also includes a programmable controller backup memory external to the display device.

[0017]

Embodiments of the present invention will be described below.
This will be described with reference to the drawings.

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

In FIG. 1, a display device 1 is connected to a PLC 2 arranged at a distance of several tens of meters by a cable 3.
The display device 1 and the PLC 2 have respective cables 3
Communication interfaces 4 and 5 are provided at the connection point with
The data is converted into communication data by the communication interfaces 4 and 5, and the data is mutually transmitted and received via the cable 3.

The display device 1 includes a memory 6, an image processing controller 7, a display screen 8, and a comparison operation controller 9.
And a work memory 10. The memory 6 includes an operation control system program area 1 of the display device 1.
1. PLC backup system program area 1
2, an image data area 13, a log data area 14, and a PLC backup memory area 15 for storing the same PLC backup data as the PLC data recorded in the memory of the PLC described later. If the PLC backup data is large and cannot be stored in the PLC backup area 15, an external memory is added and used as the extended PLC backup memory 16.

In the PLC 2, a system program 21 is stored in a ROM, and a user program area 22, a data memory area 23 such as a counter and a timer, and an I / O status area 2 are stored in a rewritable memory such as a RAM.
4 has been assigned. In order to prevent the data in the user program area 22 and the data memory area 23 from being lost due to an instantaneous power failure or the like, a backup power supply 25
Is provided. Further, the PLC 2 is controlled and instructed by the system program 21 and the user program 22 to perform arithmetic processing on data from an input / output unit (not shown) obtained via the CPU bus 26, data from the display device 1, and the like. And a bus controller 29 that distributes control signals to the CPU bus 26 and data to the data bus 28 in response to the operation result of the operation device 27.

FIG. 2 is a block diagram showing details of the function of the comparison operation controller 9 of the display device 1. The comparison operation controller 9 includes a comparison timing setting function 91, a data comparison function 92, and a log data recording function 93. , A memory content destruction point display function 94, a PLC data transfer function 95, a PLC data siphoning function 96, and a backup memory range setting function 97.

The comparison timing setting function 91 is used for comparing and comparing operations of the comparison operation controller, that is, for the PL.
The PLC backup data stored in the C backup memory 15 (or, in addition, the extension PLC backup memory 16) and the PLC data in the memory of the PLC 2 are sequentially downloaded and the work memory 10 is read.
Compare and match using PLC backup data and PL
When the C data does not match, the operator determines and sets a timing to start a series of operations for transferring the mismatched portion of the PLC backup data to the memory of the PLC 2. Normally, it is preferable to select this timing at the time of turning on the power or at regular time intervals.

The data collating function 92 sequentially compares the PLC backup data stored in the PLC backup memory 15 with the PLC data in the PLC 2 memory.
This function is to compare and match to check for a match / mismatch. Here, the PLC data is data of a user program or the like whose value does not change during operation of the PLC among data recorded in the memory of the PLC 2 and is a memory set by a backup memory range setting function 97 described later. This is the data recorded in the range. The PLC backup data is obtained by copying the above-mentioned PLC data into the PLC backup memory 15 and storing it. Therefore, the PLC data and the PL
The C backup data coincides with each other, and does not match when the PLC data is destroyed by noise or the like.

When the data collation function 92 finds a mismatch between the PLC data and the PLC backup data, the log data recording function 93 records the repaired portion of the programmable controller memory, the mismatch data, and the comparison / collation date and time as log data. This is a function for writing to the data memory 14.

The memory content destruction point display function 94 is
When a mismatch between the PLC data and the PLC backup data is found by the data collation function 92, the mismatch status is displayed on the display screen 8.

When the PLC data transfer function 95 finds a mismatch between the PLC data and the PLC backup data by the data collating function 92, the PLC backup data of the mismatched portion is converted to a PLC data memory mismatch. PLC for rewriting
The PLC data is restored to its original state by this transfer.

The PLC data siphoning function 96 copies PLC data from the memory of the PLC 2 so that the data collating function 92 compares and collates the data or backs up the data in the PLC backup memory 15. Function.

The backup memory range setting function 97
Is a function that allows an operator to arbitrarily set PLC data recorded in the memory of the PLC 2 and keeping a constant value during use such as a program. With the backup memory range setting function 97, the copying range of the PLC data copying function 96 is determined. Usually, the user program 22, the user program 22
Includes basic data related to and other important data that needs permanent storage.

The operation of the display device for a programmable controller according to the present invention configured as described above will be described below with reference to the flowchart of FIG.

In the PLC backup memory 15 and the extension PLC backup memory 16, the PLC data of the PLC 2 in the address range set in advance by the backup memory range setting function 97 is backed up. The PLC backup system program is activated at the time of turning on the power of the PLC system set by the collation timing setting function 91 and at a set time interval, and the comparison operation controller 9 operates according to the flowchart of FIG. And backed up PL
The presence or absence of destruction of the PLC data is checked in comparison with the C backup data, and if destruction is found, this is restored.

That is, when the power is turned on and a predetermined time has elapsed, comparison between the PLC data and the PLC backup data is started (step 301). By accessing a memory such as the user program area 22 of the PLC 2,
The data in the first address area is downloaded to the work memory 10 of the display device 1 (step 302), and
The collected PLC data and the corresponding PLC backup data are collated and compared by the data collating function 92 (step 303). At this time, which address data is compared and compared is displayed on the display screen 8 as shown in FIG.
The next address of the memory of the PLC 2 is accessed (step 304), and it is checked whether the address exceeds the last address backed up (step 30).
5) If not, return to step 303 and
For the next address area, the PLC data is compared with the PLC backup data. The comparison proceeds sequentially and the PLC
When all the collation of the backup data is completed, it is determined in step 305 that the final address has been exceeded, and the collation operation is terminated (step 306).

At the time of comparison and comparison in step 303, if the PLC data in the address area is destroyed and the data does not match, the memory content destruction location display function 94
As a result, as shown in the screen indicated by the arrow in FIG. 4, the mismatched part and the mismatched state are displayed on the display screen 8 (step 30).
7) The PLC backup data in the address area is transferred to the corresponding address of the PLC 2 by the PLC data transfer function 95, and is restored (step 308). Further, the inconsistency information (address, data content) and the detection date and time are further recorded in the log data recording function 9.
3 in the log data area 14 (step 3
09). Then, the process proceeds to step 304 to continue the collation.

In this manner, the presence or absence of the destruction of the PLC data is inspected at the time of power-on and every time after a predetermined time has elapsed, and if there is a destruction, the PLC data is determined based on the PLC backup data. to repair. By this collation / repair operation, the subsequent operation can be executed normally. Further, the log data of the destruction status can be saved and checked later.

Since the display device 1 is arranged at a distance from the PLC 2, the display device 1 is less susceptible to radiation noise and electromagnetic fields generated from servo motors, inverters, high-voltage power devices, and the like in the factory. Although the restoration is effective, even when the display device 1 is installed on the surface of the control panel of the PLC 2, the display device 1 is not directly connected to a source such as noise and the distance is long. For,
Since the influence of noise and the like is weak and memory destruction of the display device 1 hardly occurs, the present invention brings about an effective operation effect on the memory destruction of the PLC 2 as in the case of the arrangement remote from the PLC 2.

[0036]

As can be understood from the above description, according to the present invention, the same PLC backup as the PLC data such as the user program recorded in the memory of the programmable controller and whose value does not change during the operation of the PLC. Programmable controller backup memory for storing data, PLC backup data and PL
The PLC data is compared with the C data, and when the PLC backup data and the PLC data do not match, the PLC backup data of the mismatched portion is sent to the programmable controller for rewriting the mismatched portion of the PLC data. Since the display device is provided with the comparison operation controller for transferring and repairing, when the memory content of the programmable controller is destroyed by electromagnetic noise or the like that has entered the PLC, it is possible to find out this repair and repair it. Thus, a fatal malfunction of the PLC can be prevented.

The comparison operation of the comparison operation controller is as follows.
If the comparison and collation operation start time can be set so as to start at an arbitrary timing such as when the power is turned on or at regular time intervals, it is almost impossible to overlook the destruction of the memory contents.

Further, if the mismatch status between the PLC backup data and the PLC data due to the comparison and collation by the comparison operation controller is displayed on the display screen, the operator can easily grasp the abnormality, and depending on the situation, manually repair the parts, It is also useful for exchanging.

In a user program or the like whose value does not change during operation of the PLC, which is recorded in the memory of the programmable controller, the PLC to be backed up
If data is arbitrarily set, downloaded, and stored in the programmable controller backup memory, for example, when a user program of the PLC is changed due to a change in the production process, etc. ,
By setting the PLC data to be downloaded to the minimum required range, sufficient comparison and collation can be performed while minimizing the check time, and it is possible to flexibly cope with a change in the production process.

Further, the PLC backup data and the PLC
If the data does not match, write the repaired portion of the programmable controller memory, the mismatched data, and the comparison / collation date and time to the memory as log data, and save the data. This is effective for grasping the situation, and makes it easy to investigate how the influence of the system environment has caused the destruction of the PLC data.

[Brief description of the drawings]

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

FIG. 2 is a functional block diagram of a comparison operation controller in FIG. 1;

FIG. 3 is a flowchart illustrating a process in which a display device in FIG. 1 checks a memory of a PLC.

FIG. 4 is an explanatory diagram showing an example of a display screen when the display device in FIG. 1 checks a memory of a PLC.

[Explanation of symbols]

 Reference Signs List 1 display device 2 PLC 8 display screen 9 comparison operation controller 12 PLC backup system program area 14 log data area 15 PLC backup memory area 16 expansion PLC backup memory 22 user program area 23 data memory area 24 I / O status area

Claims (5)

[Claims] 1. A programmable controller backup memory, which stores the same PLC backup data as the PLC data recorded in a memory of the programmable controller, compares the PLC backup data with the PLC data, and compares the PLC backup data with the PLC data. A comparison operation controller for transferring the PLC backup data of the mismatched portion to the programmable controller when the data does not match, and rewriting and restoring the mismatched portion of the PLC data. Display device for a programmable controller. 2. The comparison / comparison operation start time can be set so that the comparison / comparison operation of the comparison operation controller starts at an arbitrary timing, such as when the power is turned on or at regular time intervals. The display device for a programmable controller according to the above. 3. The display device for a programmable controller according to claim 1, wherein a state of mismatch between the PLC backup data and the PLC data due to the comparison and collation of the comparison operation controller is displayed on a display screen. 4. The programmable controller display according to claim 1, wherein the PLC data recorded in the memory of the programmable controller is arbitrarily set, downloaded, and stored in the programmable controller backup memory. apparatus. 5. When the PLC backup data and the PLC data do not match as a result of the comparison and collation by the comparison operation controller, the repaired portion of the programmable controller memory, the mismatch data, and the comparison and collation date and time are stored in the memory as log data. 2. The writing method according to claim 1, wherein
3. The display device for a programmable controller according to claim 1.