JPH08202415A - Program update detecting method for programming device - Google Patents

Abstract

PURPOSE: To provide a method, which detects the update of a program by the specific programming device and makes current value data in plural programming devices correctly correspond to the program at all times, in a system which has the programming devices connected to one programmable controller. CONSTITUTION: The programmable controller(PC) 1 is equipped with a 1st update counter 5 which counts up each time a program is written from a programming device(PP) 6, 7, or 8, and the respective PPs are equipped with 2nd update counters 10-12 which store the count value of the update counter part 5 of the PC, transfers the count value of the 1st counter to the respective PPs together with the current value data of the PC each time a scan is made, and updates the count values of the 2nd update counters while reading the program out of the PC unless the count value of the 1st update counter matches the count values of the 2nd update counters.

Description

Detailed Description of the Invention

[0001]

[Field of Industrial Application] To connect a plurality of programming devices (hereinafter abbreviated as PP) to one programmable controller (hereinafter abbreviated as PC) and maintain an application program (hereinafter simply referred to as program) of the programmable controller With the necessary program update detection method, in particular, the program update state is detected in each scan cycle in the PP, and various data of the program updated every scan cycle, that is, contact ON.
The present invention relates to a method for detecting a program update state for making a correct program corresponding to a current value (hereinafter referred to as current value data) such as OFF data, counter count data, PID controller calculation data, etc. resident in a PP.

[0002]

2. Description of the Related Art In the prior art, it is desirable that the program read out to the PP and the current value data always match those of the PC main body, but the speedup of the scan cycle of the PC is sacrificed. The PC program is read out to the PP only when there is a request to read out the PC program, and normally only the current value data is output to the PP every scan cycle.

[0003]

However, in the prior art, when a plurality of PPs are connected to one PC, writing is performed when the edited and changed program is written from a certain PP to the PC. The contents of the program match between PP and PC, and the current value data also corresponds to the changed program, so the current value data and the program correspond correctly. However, in other PPs, the current value data is read from the PC to the PP and updated at every scan cycle cycle, but the program on the PP is not updated, so the program and the current value data do not correspond correctly. There was a problem. Therefore, the present invention provides a method of detecting a program update and always matching the current value data in a plurality of PPs with the program.

[0004]

In order to solve the above problems, the present invention connects one programmable controller and a plurality of programming devices by a transmission line, and outputs the current value data of the programmable controller for each scan cycle. In a program update detection method of a programming device in a programmable controller system, which is transferred to each of the programming devices and updates the current value data stored in each of the programming devices, the programmable controller includes: First to count up each time a program is written in the programmable controller
A second update counter for storing the count value of the update counter unit of the programmable controller in each of the programming devices, and each of the programming devices includes the current value data of the programmable controller for each scan. The count value of the first update counter is transferred to each of the programming devices, and if the count value of the second update counter of each of the programming devices does not match, the program is read from the programmable controller and at the same time, The count value of the second update counter is also updated.

[0005]

According to the above means, even when a program changed by a specific PP is written to the PC, the other PPs have the latest program in addition to the current value data and the second update counter in the scan cycle immediately after writing. Since the numerical value is updated, the program read by the PP correctly corresponds to the current value data displayed on the PP screen.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is an example of a system configuration in which one PC and a plurality of PPs are connected by a transmission line. 1 is a PC, 2 is a CPU, 3
Is a program to be executed by the CPU (eg a ladder program), 4 is an input / output interface, 5 is a first update counter for storing the data of the modified version of the program, and 6 to 8 are P for editing and displaying the program.
P and 9 are transmission lines, and 10 to 12 are second update counters for storing the count value read from the first update counter. FIG. 2 is a diagram for explaining the operation of the present invention. Here, PP6-8 are connected to PC1, and the contents of the update counter 5 of the program 3 and the update counters 10-12 of PP6-8 are equal. When the contents of the update counter are the same, the contents of program 3 and PP10-1
The contents of the program read in 2 are the same. Here, when the contents of the program 3 are rewritten from PP 6, the contents of the update counter 5 of the program 3 and P
The content of the update counter 10 of P6 is counted up from n-1 to n. On the other hand, since the PP7 and 8 programs are not updated, the content of the update counter indicating the version number is n.
It remains -1. At this time, when the PP 7 and 8 collect the current value data, the update counter 11 of the PP 7 and 8
Since the content (n-1) of 12 and the content (n) of the update counter 5 of the program 3 in PP7, 8 are different, the program in PP7, 8 does not correspond to the latest read current value data. Is detected. The PP 7 and 8 read a program that is not normally read in each scan cycle period (which is the n version at this point) to the PP 7 and 8 only when this mismatch is detected. As a result, PP
The current value data of 7 and 8 correspond to the correct program.

[0007]

As described above, according to the present invention, 1
In a system in which one programmable controller and a plurality of programming devices are connected to the programmable controller, the first update counter data is added to the programmable controller, and the second update counter data is added to each programming device. Various data of the program read by the device and the program updated every scan cycle, that is, the contact O
The present value (present value data) such as N / OFF data, counter counting data, and PID controller calculation data can be correctly associated.

[Brief description of drawings]

FIG. 1 System configuration example using a PC and multiple programming devices

FIG. 2 is an operation explanatory diagram of the present invention.

[Explanation of symbols]

 1 Programmable Controller 2 CPU Executing Program 3 Program 4 Input / Output Interface 5 First Update Counter 6-8 Programming Device 9 Transmission System 10-12 Second Update Counter

Claims (1)

[Claims] 1. A programmable controller and a plurality of programming devices are coupled by a transmission line, and current value data of the programmable controller is transferred to each of the programming devices for each scan cycle and stored in each of the programming devices. A program update detection method for a programming device in a programmable controller system adapted to update the present value data, wherein the programmable controller counts up every time a program is written from the programming device to the programmable controller. An update counter is provided, and each programming device is provided with a second update counter that stores a count value of the update counter unit of the programmable controller. When the count value of the first update counter is transferred to each of the programming devices together with the current value data of the programmable controller and the count value of the second update counter of each programming device does not match, A program update detection method for a programming device, wherein the count value of the second update counter is updated at the same time when the program is read from the programmable controller.