JPS6184707A - Programmable logic controller, program method and device - Google Patents

Abstract

PURPOSE:To make an adjusting work of a facility simple by installing a programming circuit between PLC (programmable logic controller), connecting a programming device to a desired PLC in a software manner and communicating the data. CONSTITUTION:Plural PLCs 15-18 are connected to facilities 1-4 of a production line, and further, a programming device 41 is installed. Respective PLCs 15-18 are linked with a data exchange device 12, the programming device 41 is connected with PLC17 by a communicating circuit 42, and the circuit 42 is connected with a programming circuit 50 between PLC. Thus, transmitting data from the programming device 41 are sent through a circuit in the PLC17 to the circuit 50 and a deciding gate circuit, and can be received with all PLC. For this reason, while the programming device 41 is connected to PLCs 15-18 located at the processing unit to be adjusted, the program of dispersed and arranged PLCs 15-18 can be prepared and corrected.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a programmable logic controller (hereinafter referred to as
The present invention relates to a PLO (abbreviated as PLO), and in particular to a PLO and its programming method and apparatus applied to a processing equipment control system composed of a plurality of PLCs.

[Background of the invention]

Processing equipment such as automobile body production lines has multiple processing units.
Each processing unit performs only one or two types of work, and these processing units are connected by a conveyor such as a belt conveyor.

Programmable logic controllers (PLOs) have been used to control these processing equipment. As schematically shown in Figure 1, the entire production line is integrated into one large WP.
When controlling centrally with LC, PLClo and processing equipment 1
The cable wiring 20 that has a long distance from the cable wiring 20 is very large and long. Furthermore, the control program within PLClo has become extremely large and complex. The disadvantage is that it takes a very long time to create and modify.

Therefore, when starting up a production line, it is better to test the equipment and combination of each processing unit individually and then create a program for the entire flow, which will shorten the start-up period for the entire production line. Each processing UNI as shown in
PLCs (11 to 14) are installed for each T, and the PLCs are connected by a data exchange device 21 that exchanges conveyance information such as the type of vehicle body that has just been processed.

When PLO is distributed across production lines in this way, 1
The combination and programming of the PLO of the machine and the machining unit that is its control range can be started by connecting a programming device to the PLO, but conventionally, the PLC and programming device were connected one-to-one. Therefore, at the stage of starting up the entire combination, for example, if the input data from machining unit 3 to machining unit 4 is abnormal and the movement of machining unit 4 is malfunctioning, the PL
PL the programming device 40 connected to C14.
It was necessary to change the connection to C13 and modify the PLC13 program. For this purpose, it is necessary to move the programming device 40 from the processing UNIT 4 to the processing UNIT 3, and as a result, the movement of the processing UNIT 4 may become invisible, or a long connection cable may be routed from the PLC 13 of the processing UNIT 3 to the programming device. The drawback was that 40 had to be brought to processing unit 4.

Further, some processing equipment has a parts supply line that intersects with the production line in order to supply parts and the like to the production line. In such so-called cross-arrangement processing equipment, it is no longer possible to perform centralized control using a conventional large-scale PLO or to construct a system using the data exchange device 21 shown in Fig. 2. This was a problem because it took too much time.

[Purpose of the invention]

An object of the present invention is to provide a PLC, a programming method, and an apparatus for shortening the startup and adjustment period until actual operation of a production line controlled by a plurality of PLCs.

[Summary of the invention]

In the present invention, a programming line is provided between the PLCs in a plurality of PLOs that are correlated with each other, and programs can be created, modified, and monitored from a programming device connected to any PLO connected to this line. P
The LO number is sent to the line, the desired PLC is connected via software, and the subsequent series of data communications are controlled by a specific PLC.
The feature is that the above objective is achieved by performing the process only with the LC.

[Embodiments of the invention]

Hereinafter, the present invention will be explained using the drawings.

FIG. 3 shows an example of application of the present invention, and shows a state in which production line equipment (1 to 4), a plurality of PLCs (15 to 18), and a programming device 41 are connected.

FIG. 4 shows the internal configuration of the PLO to realize the present invention. The input/output section 17a is the input/output circuit 17b.
The input/output circuit includes a judgment gate circuit 17C and a line circuit 171.

Each PLC 15-18 is connected by a data exchange device 21 (FIG. 3).

The programming device 41 is connected to the PbCl 7 by an inter-programming device communication line 42, which is connected to an inter-PLC programming line 50 through a line circuit 171, as shown in FIG.

By doing this, the transmission data from the programming device 41 is transmitted through the entire line circuit 171 in PbCl7 to the PL.
C programming line 50 and judgment gate circuit 17C
and can be received by all PLCs.

Hereinafter, a case will be described in which the program for PbCl2 is read by the programming device 41 in the connection state shown in FIG. 3.

First, the keyboard 146 (fifth
Enter the PLO number 16 manually from the figure below.

The data transmission program in the programming device 41 shown in FIG. 5 is activated by this key manual power (FIG. 6).
. In other words, the command $“ that specifies the PLO number for the line
The data is sequentially converted into "PbCl2" and an ASCII code and sent to the inter-PLC programming line 50. after that,
In order to confirm the connection of PbCl2, it waits for a response from PbCl2, and if there is a normal response, the display device 143 of the programming device 41 displays that the line is normal and displays that the subsequent operations on the programming device will communicate with PbCl2.

On the other hand, if there is no response even after requesting a response from PbCl2 a certain number of times, for example 16 times, a line abnormality is displayed on the display device 143 (FIG. 5') and transmission of the connection request to PbCl2 is stopped.

If the line is connected normally, the programming device 41
From the keyboard 146 of
As shown in the figure.

The programming device is, for example, US M-100,=301
and program read command on the line, and PbC
Wait for response from l2. When the response from PbCl2 is completed, the received program contents of PbCl2 are displayed on the display device 143.

8 and 9 show the line data processing procedure on the PLC side. When data is received from the line, if the data is a command starting with 1$1, it is treated as a command specifying a PLO number, and compared with the value of the PLO number setting circuit 174 to determine whether or not the own machine is specified. .

If the own machine is specified, the PLc number specification flag is set in order to process subsequent commands from the programming device as being directed to the own machine, and
A response signal to the programming device (e.g. “$PC$
″) will be returned.

If the PLO number designation is different from your own aircraft number, the above PL
The O number designation flag is reset, and no response will be made to any commands on the line until the PLO number designation command starting with "$" specifies the PLC number of the own machine.

In the example in Figure 3, if PLO number 16 is specified, PLC15
, 17, 181 The DPLC number designation flag is reset, and only the flag for PLC 16 is set.

Following the designation of the PLO number, when the program read command 1*M" is received, the PLO responds with 30 words of data from the designated address 100 of the sequence program area of its own machine to the programming device, and when the program is completed. The system enters a state of waiting for a new command (Figure 9).

When modifying a program, use another command to
Write to the internal program area using the programming device.

〔Effect of the invention〕

According to an embodiment of the invention, a programming device connected to the PLO located at the processing tJNIT to be adjusted,
It becomes possible to create and modify programs for the PLCs that are distributed in order to control the production line, and there is no need to move the programming device, which has the effect of simplifying the adjustment work of production equipment.

[Brief explanation of the drawing]

Figure 1 is a system diagram in which four machining units are controlled by one large PLO, Figure 2 is a system diagram in which the PLO is distributed to each machining unit, but the programming device is carried around, and Figure 3 is a system diagram in which the programming device is carried around. A system diagram to which the present invention is applied, FIG. 4 is a diagram showing the internal connections of PLO, FIG. 5 is a block diagram of the programming device, FIGS. 6 and 7 are flow charts of the program in the programming device, and FIG. P
When specifying the LO number, Figure 7 shows when reading the control program from the specified PLO, and Figures 8 and 9 show the PLC.
3 is a flowchart of a program for an internal transmission line. 1-4...Processing shop, 5...Transport machine, 15-1
8...PLC, 41-Programming device, 42-
...Communication line between programming devices, 5o...PLC
inter-programming line, 143...display device 146
...Keyboard, 174...PLC number setting circuit,
178... Line processing circuit, 177... PLO control device, 142... Programming device transmission/reception circuit.

Claims (1)

[Scope of Claims] 1. A programmable logic controller that controls machining equipment consisting of a combination of units having processing equipment via a processing equipment drive circuit connected to the processing equipment, An input/output circuit connected to a programming device and another programmable logic controller, in a device having a control arithmetic device and a storage device that can independently perform control operations of a processing device, the input/output circuit being connected to a programming device and another programmable logic controller. A programmable logic controller having a device for programming, and suitable for programming a programmable logic controller to which the programming device is connected and other programmable logic controllers. 2. In the programmable logic controller according to claim 1, the input/output circuit includes a program input/output terminal connectable to a programming device, and a connection input/output terminal for connecting another programmable logic controller. a line circuit in which the program input/output terminal is connected to the connection input/output terminal and a judgment gate circuit; 2. The programmable logic controller according to claim 1, further comprising the judgment gate circuit which transmits and receives signals between the circuit and the control arithmetic unit. 3. A method for programming a plurality of mutually connected programmable logic controllers, wherein the programmable logic controller has at least a control arithmetic unit connected to an input/output circuit therein; After sending a predetermined number among them from the programming device to the arbitrary programmable logic controller, the sent signal is sent to the control arithmetic unit of the programmable logic controller specified by the number to control the input/output circuit. and sent to another programmable logic controller connected via the input/output circuit of the programmable logic controller not specified by the number, the programming device 1. A method of programming a programmable logic controller, characterized in that communication is possible with the logic controller and data is exchanged via the connection or directly. 4. Consisting of a display control circuit connected to the display device, a keyboard control circuit connected to the keyboard, a transmitting/receiving circuit connected to the programmable logic controller, a control arithmetic device and a storage device, and a bus signal line, A function of inputting the number of a predetermined programmable logic controller from the keyboard and sending it to the programmable logic controller via the transmitting/receiving circuit, and communication with the predetermined programmable logic controller, A programmable logic controller having at least three functions: a function of reading a program from a storage device and displaying it on the display device, and a function of writing a program to the storage device of the programmable logic controller through communication with the predetermined programmable logic controller. programming device.