JPH02168302A - High-order link unit for programmable controller - Google Patents

Abstract

PURPOSE:To prevent a timing gap between the data processing of a computer and the control operation of a controller by executing the operation of a programmable controller from a host computer at every one control period. CONSTITUTION:In the case where a command from the host computer 1 is received, a CPU 12 interprets the command in conformity to the system program of a system program area 11 by using a work area 14, and outputs an access request signal of a shared data area 22 to the access control circuit 24 of the programmable controller 20. Then, it waits the input of an access permission signal from the controller 20. On the reception of this permission signal, it makes to access the shared data area 22 synchronously with it, and reads in the requested data from the host computer 1. After finish, it waits the input of the next command from the host computer 1.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to an upper link unit connected between a host computer and a programmable controller, and more specifically, to a sequence Φ program on the host computer side. A programmable controller used in a data processing system that exchanges data between a host computer and a memory area of the programmable φ controller while repeatedly executing and stopping the programmable φ controller every control cycle of a sequence program. Regarding the improvement of the upper link unit.

<Prior art> When a host link unit of a programmable controller receives a data request command or a data setting command from a host computer, it interprets the received command, accesses the data area of the programmable controller, and performs the setting. Write data or read requested data. It also has a function of sending processing results and data back to the host computer.

In this case, each time the host computer monitors or sets programmable controller data, it sends a command to the upper link unit, interprets the received response, and performs data processing and display processing. I will do it.

<Problems to be Solved by the Invention> However, due to economic reasons and other reasons, slow transmission lines are often used between the host computer and the upper link unit, and data transmission is This is often done by serial transmission.

As a result, the data transmission processing timing in the host bone computer lags behind the control operation of the programmable controller, and the scan time in the host computer increases, making it impossible to capture the timing of data changes in the programmable controller. . Therefore, data loss occurs in the sample number data in the host computer.

This means that during debugging, in which a sequence program created on the host computer is downloaded to the programmable controller through the host link unit and checked on the host computer while actually running it, the sequence program created on the host computer and the programmable controller are This causes the inconvenience that the operation timing with the controller does not match.

The present invention has been made in view of the above-mentioned problems, and its purpose is to collect the operating mode information of the programmable controller set by the host link unit every time the programmable controller accesses the data area. By confirming this, the upper link unit can perform control to eliminate the difference in operation timing between the host computer and the programmable controller.

Means for Solving the Problems> The programmable programmable computer of the present invention to achieve the above objects.
The upper link unit of the controller includes a mode setting means for setting the upper link unit to a remote operation mode according to a specific command received from the host computer, and a mode setting means for setting the upper link unit to a remote operation mode in accordance with a specific command received from the host computer, and a mode setting means for setting the upper link unit to a remote operation mode in accordance with a specific command received from the host computer, and a mode setting means for setting the upper link unit to a remote operation mode. , a comparison means that counts the number of accesses to the memory area in the programmable controller and compares it with a predetermined set number of times, and a stop that stops the execution operation of the programmable controller when the number of accesses exceeds the predetermined set number of times. and control means.

Effect〉 When the user downloads the sequence program on the host computer and sets the above specific command, the upper link unit with the above configuration sets itself to remote operation mode and disconnects from the host computer. According to the settings of the received data control command, the programmable controller is repeatedly executed and stopped in a specified pattern for each control cycle. This allows data in the memory area within the programmable controller to be monitored and data to be set in the memory area.

In this case, the number of data accesses is limited by the comparison means and stop control means, so no matter how large the amount of data is, data transfer is stopped midway and the programmable controller is executed in the relevant control cycle. can be terminated promptly. Therefore, it is possible to prevent a timing shift between the data processing operation of the host computer and the control operation of the programmable Φ controller.

<Example> Embodiments will be described in detail below with reference to the accompanying drawings showing embodiments.

In this embodiment, the sequence number program created by the user on the host computer is transferred to the programmable fist controller via the upper link unit, and the programmable fist controller is programmed according to instructions from the host computer.
Execution and execution according to the system program in the controller
An example will be described in which the operation of a sequence program is debugged by repeating the stopping operation and combining it with monitoring processing and setting processing of data stored in the programmable fist controller.

FIG. 2 is a block diagram showing the system configuration of the programmable controller (20) to which the upper link unit (10) is connected. A communication transmission line (15) connects the host computer (1) and the upper link unit (1O).
), and the upper link unit (10) and programmable controller (20) are connected via path lines via connectors (17) and (35), respectively.

As is well known, the upper link unit (IO) includes the CPU (12), system program area (
11), work area (14), communication controller (1
3), etc., and the system bus (1) as shown in the figure.
They are connected to each other through B). CPU (12)
is mainly composed of a microprocessor and operates according to a system program stored in a system program area (11). The work area (14) is
It is used to store intermediate results of various calculations performed by the CPU (12). A communication controller (13) performs transmission and reception operations with the host computer (1).

To give an overview of the operation of the above-mentioned upper link unit (10), when a command is received from the host computer (1) through the communication controller (13), the CP
U (12) uses the work area (14) to interpret the command according to the system program in the system program area (11), and executes the programmable program described below.
outputting an access request signal for the shared data area (22) to the access control circuit (24) of the controller (20);
It waits for an access permission signal (hereinafter, the access request signal and the access control signal are collectively referred to as the "access control signal") to be input from the programmable fist controller (20). And if the access permission signal is input,
At the same time, after accessing the shared data area (22) and reading the data requested by the host φ computer (1), or changing the data setting values in the shared data area (22), the programmable An access end signal is output to the prayer controller (20), and the series of operations ends. Thereafter, it waits to receive the next command from the host computer (1).

On the other hand, the programmable fist controller (20) includes a shared data area (22), a CPU (25), a system program area (2B), and a user program area (2B) that are internally connected through a system bus (29).
7) and a work area (28), a peripheral unit side buffer (21) that connects the shared data area (22) and the upper link unit (10) through the system bus (30), and a shared data area (22). ) and the internal equipment of the programmable controller (20), as well as the CPU of the upper link unit (IO) and the CPU of the programmable controller (20).
(25) and an access control circuit (24) that transmits connection on/off signals to the peripheral unit side buffer (21) and the PC unit side buffer (23).

The CPU (25) has a system program area (
26), input/output processing using an input/output device (not shown), interpretation and execution of user programs stored in the user program area (27), and execution of upper link services. The processing is performed cyclically in this order.

The work area (2B) is used for temporarily storing intermediate calculation results of the CPU (25). In addition, the shared data area (22) is used by the programmable controller (20) itself or by the host computer (1) through the upper link unit (IO), and which one uses it depends on The access control circuit (24) is determined by transmitting on/off signals to the peripheral unit side buffer (21) and the master to the PC unit side buffer (23). In addition, the access control circuit (24
) is the CP in the programmable Φ controller (20)
Based on the access request signal from U (25), C
An access permission signal is output to the PU (25), and the CP! An access permission signal is given to J(12).

Next, the processing procedure of this embodiment will be explained in detail using the flowcharts of FIGS. 1 and 3.

First, referring to FIG. 3, after turning on the power, the programmable controller (20) initializes the hardware environment of the programmable controller (20) (step ■) and checks the connection status of peripheral units. (Step ■). Then, it is checked whether the upper link unit (10) is connected or not (step (2)), and if it is not connected, the process jumps to step (2). If it is connected, the upper link unit (lO)
It is checked whether an access request signal to the shared data area (22) has been issued from the shared data area (22) (step 2). If there is no access request, the process jumps to step 2. If there is an access request, an access permission signal is given to the upper link unit (IQ) (step 2), and an access end signal is output from the upper link unit (IO). Wait for (step ■). When the shared data area (22) is released from the upper link unit (lO), it is checked whether the operation mode designation of the programmable controller (20) is run mode or stop mode (step 2). If it is in the execution mode, the program executed by the user is executed (step (2)), and if it is in the stop mode, it jumps to step (2) and performs system processing. The programmable controller (20) repeatedly performs the series of operations of steps (1) to (2) above.

The upper link unit (10) operates as shown in FIG. 1 when connected to the programmable controller (20). Usually, the power supply is a programmable controller (20
), so when the upper link unit (lO) is connected to the programmable controller (2o), the upper link unit (10) is reset.
The upper link unit (10) first performs initialization processing (step [phase]). Thereafter, after performing system processing to prepare the operating environment (step ■), it waits for a command from the host computer (1) (step @). When a command is received from the host computer (1), the contents are interpreted and an error check is performed (step ■).

If there is an error, jump to step 0 and return a response to the host computer (1). If there is no error, it is checked whether there is a remote operation request command (step ■). If it is a normal command that is not a remote action request command, jump from step ① to step ②. If it is a remote operation mode request command, the upper link unit (10) is set to remote operation mode (step @), and the programmable controller (
2o) Set the execution mode flag (step ■)
. Then, the value C of the access permission signal input counter is set to 0, and the value Co (described later) is set to the set value (step @
). Thereafter, the shared memory area access request signal is sent to the programmable controller (20)1. : Notify (step ■) and wait for an access permission signal to be returned from the programmable controller (20) (step [phase]
).

When the access permission signal is received, the upper link unit (
IO) accesses the shared data area (22). First, check whether the host link unit (10) is in remote operation mode (step ■). If it is not in remote operation mode but in normal mode, perform normal command processing (data polling settings, etc.) (step ]
). Proceed to step [phase]. In the remote operation mode, first, the execution mode flag of the programmable Φ controller (20) is turned on to execute the programmable ψ controller (2o) (step @), and the access permission signal input counter IC changes to the set value Co. Check whether it has been reached (step ■). The set value Co is
This is a natural number preset by the user. If the set value Co has not been reached, the value C of the access permission signal input counter is incremented by 1 (step ■). Then, the process returns to step [phase] and waits for the access permission signal to be issued from the programmable controller (20) again. Each time an access permission signal is input in this way, the number of inputs is counted (step ■) and compared with the set value Co (
Step ■). If the result matches the set value Co, the stop mode flag is turned on in the programmable pot controller (20), and the programmable pot controller (20)
(step o), release the access request state to the programmable controller (20) (step 0), and end the remote operation mode.

When access to the programmable fist controller (20) is completed, the CPU (12) returns to the host computer (
1) and sends it (step 0). The above series of operations from step (1) to step 0 are repeated in the upper link unit (10).

To summarize the above, when the programmable controller (20) is in a stopped state, the programmable controller (20)
The execution of the controller (20) is as shown in step 3 of FIG.
Repeat the series of ■, ■, ■.

Here, when the user downloads the sequence program from the host computer (1), the operating procedure of the programmable controller (20) does not change even during the transfer, and the steps ■, ■, ■、■
repeat. However, when a sequence program is transmitted between the upper link unit (lO) and the programmable controller (20), the programmable urn controller (20) performs the steps ■, ■, ■, ■, ■
, ■ will be repeated.

Here, when the upper link unit (lO) enters the remote operation mode, the programmable controller (20)
enters the execution mode and performs sequence operations according to the user program transferred to the programmable controller (20) by the user. At this time, the operation procedure of the programmable pot controller (20) is as follows:
The cyclic operation is ■, ■, ■, ■. In other words, 1
Every time a sequence operation for the control period is performed, the access right to the shared data area is passed to the upper link UniSoto (IO), and the programmable controller (20) is operated while checking whether or not it is set to execution mode. There is.

On the other hand, when downloading a sequence program from the host computer (1) to the programmable controller (20), the upper link unit (10) performs steps ■, ■, or step ■.

Repeat the processing of @, ■, ■, ■, ■, ■, ■, [phase], 0. In the latter case, the upper link unit (lO)
This is the procedure to be followed when a download command is received from the computer (1) (step ①).

After downloading the sequence program and entering the remote operation mode, the upper link UniSoto (lO) will perform the steps ■, ■, ■, [Yes], ■, ■, ■, @.

Execute ■, [phase], ■, @, and then step ■ is Y
Repeat steps [phase], ■, @, ■, ■ until ES is reached. When step (2) becomes YES, set the programmable urn controller (20) to stop mode and stop the execution of the programmable controller (20).

As described above, when step ■ becomes YES,
Since the execution of the programmable controller (20) is forcibly stopped and the execution of the programmable controller (20) is waited for the next command, it is possible to reliably operate the programmable controller (20) in accordance with the operation timing of the host computer (1). Then, on the host computer (1) side, refer to the data obtained in the above procedure, change the setting values as the case may be, and set the remote operation mode again.
By operating the programmable controller (20), data can be efficiently acquired.

As a result, it becomes easier to see the operation timing of each terminal device (e.g. limit switch or relay contact) connected to the input/output device of the programmable controller and the cause-and-effect relationship between input and output, making it possible to modify sequence programs during debugging, for example. becomes very easy.

<Effects of the Invention> As described above, - According to the upper link unit of the programmable controller of the present invention, the operation of the programmable controller can be executed every control cycle from the host computer, and can be executed as many times as desired by the user. You will be able to retrieve data and view the results. Therefore, a unique effect can be obtained in that it is possible to reliably prevent a lag in the operation timing between the data processing operation in the host computer and the control operation in the programmable φ controller.

[Brief explanation of the drawing]

Fig. 1 is a flowchart explaining the processing procedure in the upper link unit, Fig. 2 is a block diagram showing the system configuration of the programmable controller to which the upper link unit is connected, and Fig. 3 explains the processing procedure in the programmable controller. It is a flowchart. (10)...Upper link unit, (12)...C
P.U. (20)...Programmable controller, (22
)...shared data area

Claims (1)

[Claims] 1. Sequence on the host computer side ・Sequence program according to the program Executes/stops each program control cycle Repeat this until the host computer A programmer who sends and receives data to and from a computer. The upper link connected to the a link unit, Specifies the characteristics received from the host computer. according to the specified command. Setting the knit to remote operation mode Mode setting means and remote operation mode is set to Programmable control for each control cycle. Access times to the memory area in the roller A comparison method that counts the number and compares it with the standard number of times. The number of accesses exceeded the standard number of times. If the programmable controller stop control means for stopping the execution operation of the A programmer characterized by comprising: upper link unit of the to.