JPH0582616B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a programmable data remote input/output transmission path (hereinafter referred to as a remote I/O transmission path).
Regarding programmable controller systems that connect units such as basic controller units and input/output units, particularly programmable controller systems that can be connected to programming devices for programming and monitoring.
It's about systems.

[Prior Art] Conventional programmable controller systems of this type include basic units such as programmable controllers located at separate locations, and remote input/output units (remote I/O units).
There are devices in which a programming device is coupled to a remote input/output device (O unit) or remote input/output device (remote I/O device) so that programming and monitoring can be performed via a remote I/O transmission line.

[Problems to be Solved by the Invention] However, in such programming devices, identification (station number setting) is done at the same time as the power is turned on, so when multiple devices are connected, the same There was a problem in that because the returned station number was carried over the transmission line, collisions occurred on the data line of the transmission line, causing confusion on the line.

The present invention solves this problem, and when a plurality of programming devices are connected to a remote I/O transmission line, each of them is correctly identified without overlapping. It is an object of the present invention to provide a programmable controller system that can prevent collisions and thereby perform smooth transmission and reception.

[Means for solving the problem] Therefore, in the present invention, as shown in FIG.
In a programmable controller system having a data transmission path 200, the data transmission path 2
00, the programming device 210 includes a signal generating means 204 that generates a request signal for requesting processing when processing using the data transmission path 200, and a signal generating means 204 that generates a request signal for requesting processing when the data transmission line 200 is used, and a data A coupling control means 206 disconnects the electrical connection from the transmission line 200, performs electrical coupling when a request signal is generated, and sends the generated request signal to the data transmission line 200; 200, and a control device 220 connected to the data transmission line 200. Transmission line 20
recognition means 222 that recognizes the connection status of a plurality of programming devices connected to 0, and connection information transmission means that receives a request signal and sends the connection status recognized at the time of reception to the data transmission path 200 as connection information. 224.

[Operation] That is, according to the present invention, the programming device 210 connected to the transmission path temporarily disconnects from the data transmission path 200 when the power is turned on and before transmitting the request signal. When a processing request is generated from the programming device 210 to the control device 220, the processing request is transmitted by connecting to the transmission path, and the processing request is not overlapped with others according to the connection information given in connection with the connection. It becomes possible to set a station number, and reliable communication can be performed on the data transmission path.

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

FIG. 2 shows an example of the configuration of a programmable controller system including a programming device. Here, 2 is the remote I/O unit of the programmable controller, and 3 is the remote I/O unit.
The transmission device 4 is a remote I/O transmission line. 1
Reference numeral 1 denotes a basic unit of the system, which includes a CPU that processes sequence programs and executes the processing procedures shown in FIG. 4, and a memory that stores these processing procedures and sequence programs. 15
is a programming device according to this embodiment, and as shown in the figure, a plurality of connections can be made in the system. In addition, in order to simplify the explanation, FIG. 2 shows a case where only two programming devices are connected.

FIG. 3 shows an example of the internal configuration of the programming device 15. Here, programming device 15
For example, the CPU 51 in the form of a microprocessor,
It has a memory 52, a display 53, a keyboard 54, a transmission interface 55, and a station number setter 56, which are interconnected by an internal bus 57.
The transmission interface 55 receives the station number value signal from the station number setter 56 via the signal line 58, and transfers the station number to the transmission line 4 via the connection cable 59 and the transmission interface 35 of the remote I/O device 3. Although the programming device 15 is connected to the transmission line 4 via the remote I/O device 3 in FIG. 3, it may be connected directly to the transmission line 4.

Here, the basic unit 11 sends a signal to the programming device 15, in addition to a signal having an area for the station number of the destination programming device and an area for commands to the programming device, as well as a connection to notify the programming device of the connection status. To transmit information signals. Commands placed in the command area include processing inquiry signal, processing completion signal,
A processing incomplete signal or the like can be provided. Also,
The connection information signal indicating the connection state of the programming device 15 should be, for example, a signal string in which one bit corresponds to one station number, and the programming device 15 should be able to recognize the connection state by turning each bit on or off. I can do it.

Further, from the programming device 15 to the basic unit 11, for example, the basic unit 1 as a transmission destination is sent.
1 is provided with the station number "0", and various processing requests to the basic unit 11 are provided, such as memory write requests, read requests, interlock set requests to lock processing requests of other programming devices, and their reset requests. A signal having a certain area is transmitted.

FIG. 4 shows an example of a procedure in which the basic unit 11 sends a signal to the programming device, which can be activated, for example, by a fixed time interrupt. First, steps STPA and STPB
is a process for causing the programming device to set a station number. That is, when a processing request is received from a programming device for which a station number has not been set, the basic unit 11 sends a signal indicating the connection information at that time to the remote I/O transmission line 4, and sets the station number of the programming device, which will be described later with reference to FIG. Serve. In addition,
If processing requests are received from multiple programming devices related to these processes, that is, if another processing request is received before connection information is sent in response to one processing request, connection information will not be sent. This is done to prevent the same station number from being set in multiple programming devices.

Next, in step STP1, a counter k indicating the station number is incremented by one, and then in step STP2 it is determined whether the value of k exceeds the total number of connections. If the judgment is affirmative here, k=1 is set at step STP3 and the process moves to step STP4, and if the judgment is negative, the process immediately moves to step STP4 and starts the transmission process to the programming device having the station number k. .

That is, in step STP4, a signal containing the station number k and a processing inquiry signal is sent out. In response to this transmission, if a signal including a processing request is received from the programming device with station number k at step STP5, connection information is checked at step STPC. For example, if there is a processing request from a programming device that newly joined the line and set the station number,
Update accordingly and take steps next time.
Enable the connection information sent by STPB to be changed.

Next, in step STP6, processing according to the request is performed, and the process proceeds to step STP7. step
In STP7, a signal including a process completion signal or a process incomplete signal for process identification is transmitted, and one process is completed.

By performing this processing procedure at predetermined intervals, it is possible to sequentially transmit and receive data to and from the connected programming devices.

In the system as described above, the station number setting process of the programming device when the programming device is connected to the transmission line 4 will be described.

FIG. 5 shows, as an example of the station number setting procedure performed by the programming device, the processing when there are two programming devices connectable to the system. First, when setting the station number when turning on the power, etc., use step STPX to set the programming device 1.
5 and the remote I/O transmission device 3 is disconnected. Next, in step STPY, in response to an operator's operation, etc., the unit waits in a disconnected state until it issues some kind of processing request to the basic unit 11, and if a processing request occurs, it moves to step STPZ. The line is connected, and if the line is available, that is, if the basic unit 11 is not communicating with another station, the processing request is transferred to the basic unit 11.

This processing request can be accepted by the basic unit 11 in step STPA of FIG. When the basic unit 11 transmits the connection information in response, the CPU 51 of the programming device 15 analyzes the received connection information frame in step STP11. Then step
Through the processing of STP12 to STP15, a vacant station number is set in its own station number setter 56. Note that if there is no vacant station number, the step
At STP16, a message indicating that connection to the transmission path 4 cannot be made is displayed on the display 53.

In this way, according to this example, the station number on the transmission path is set in relation to the process of issuing some kind of processing request from the programming device to the basic unit, etc. Transmission and reception related to programming, monitoring, etc. to and from a programming device can be performed smoothly without conflict.

Additionally, if a processing request is made to the basic unit from multiple programming devices at the same time, each request will be treated as an error and canceled, no connection information will be given, and the next processing request will be made again from the programming device. Since the station number is not set until , a collision on the data line is prevented.
In other words, the next time a programming device makes a processing request, there is a very low possibility that another programming device will make a processing request at the same time.Therefore, the station number can be set reliably and without any inconvenience. become.

In this embodiment, for the sake of simplicity, a system in which two programming devices can be connected has been described, but it goes without saying that any number of programming devices may be used depending on the processing capacity of the basic unit. stomach.

In addition, although the disconnection and connection of circuits by the programming device was performed by software in the above embodiment, appropriate logic circuits etc. may be provided.
It is also extremely easy to implement this using hardware.

[Effects of the Invention] As explained above, according to the present invention, when a plurality of programming devices are connected to a remote I/O transmission path, the station number settings of each of them can be correctly identified without overlapping. Therefore, collisions on the data line can be prevented, and the programming device can be attached to and detached from the data transmission line while the line is live, thereby realizing a programmable controller system that can perform smooth and reliable transmission and reception.

[Brief explanation of drawings]

FIG. 1 is an overall configuration diagram of the programmable controller system of the present invention, FIG. 2 is a block diagram showing an embodiment of the present invention, and FIG. 3 is a block diagram showing an example of the configuration of a programming device applicable to the present invention. 4 is a flowchart showing an example of a signal transmission processing procedure performed by the basic unit, and FIG. 5 is a flowchart showing an example of a station number setting procedure performed by the programming device. 2...Remote I/O transmission unit, 3...Remote I/O device, 4...Transmission line, 11...Basic unit, 15...Programming device, 51...CPU,
52...Memory, 53...Display device, 54...Keyboard, 55...Transmission interface, 56...Station number setting device.

Claims (1)

[Scope of Claims] 1. In a programmable controller system having a data transmission path, a programming device connectable to the data transmission path, which requests processing for processing using the data transmission path. A signal generating means for generating a signal is electrically disconnected from the data transmission line when the power is turned on and before the start of the processing, and when the request signal is generated, the electrical connection is performed to generate the generated request signal. connection control means for transmitting the request signal to the data transmission path; and station number setting means for setting a vacant station number based on connection information of a programming device received via the data transmission path when transmitting the request signal. and a control device connected to the data transmission path, recognition means for recognizing the connection state of the plurality of programming devices connected to the data transmission path;
A programmable controller system characterized by comprising a control device having a connection information transmission means that receives the request signal and sends the connection state recognized at the time of reception to the data transmission path as connection information. 2. In the programmable controller system according to claim 1, when the connection information transmission means receives a request signal from one programming device and before transmitting the connection information, the connection information transmission means transmits the request signal from another programming device. A programmable controller system comprising means for not transmitting the connection information when a request signal is received.