JPS6329803A - Switching data control system in loop control system - Google Patents

Abstract

PURPOSE:To control all controllers or the like based on the same data during one circulation of a loop control system by forming two command memory, and even if new switching data are updated from a sequence control device on the way of execution in the loop control system, waiting the data in one common memory. CONSTITUTION:A step type sequencer 1 stores switching data 'R/L1', e.g., in a 1st common memory 3 through a terminating table 5 and switches originating data in an originating table 6 to '0'. The originating data '0' are allowed to correspond to the 1st common memory 3. At the time of starting the circular execution, the loop control system refers the originating table 6 and respective controllers 7, 8 receive the switching data 'R/L1' stored in the common memory 3 corresponding to the originating data '0' and drive a change-over switch 11 in an R/L switching part 10 to execute R/L switching. Simultaneously, the loop control system switches the terminating data in the terminating table 5 to '1'. The terminating data '1' are allowed to correspond to a 2nd common memory 4.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a switching data control method for performing remote/local switching of set values in a loop control system by a sequence control device.

(Prior art and its problems) Conventionally, as a control method for this type of switching data, a common memory is interposed between the sequence control device and the loop control system, and data is written into the common memory by the sequence control device. A method has been proposed in which a loop control system reads and executes switching data such as setting values. In this method,
When the sequence control step shifts and new switching data is written to the common memory, it is necessary to manage reading and writing of data using a semaphore or the like in order to stop referring to the switching data from the loop control system.

In addition, if the loop control system is composed of multiple controllers, etc., and if the data is switched during a cycle of all controllers, the control during that cycle will be This has caused the problem that the controller is controlled according to different set values.

The present invention has been proposed in order to solve the above problems, and its purpose is to solve the above problem even when data is switched from the sequence control device during one round of execution of the loop control system. An object of the present invention is to provide a switching data control method that makes switching data temporarily standby and completes execution of a loop control system using previous data, thereby making it possible to unify set values and the like in the loop control system.

(Means for Solving the Problems) In order to achieve the above object, the present invention assumes a method in which data used for loop control is switched via a memory in accordance with the transition of steps by a sequence control device, and , the main components are first and second common memories that store switching data such as remote/local switching of the controller and are selected according to the destination data, and destination data that is selected according to the destination data by execution of the loop control system. It includes a destination table that changes and a destination table that changes destination data as the sequence control device moves from step to step.

Then, the loop control system performs a round of execution according to the switching data in one common memory that corresponds to the destination data referenced when starting the execution, and at the same time transfers the destination data in the destination table to the other common memory. It is characterized by switching to destination data corresponding to the switching data.

(Function) In the present invention, switching data is stored in one of the common memories by the step transition of the sequence control device, and at the same time, the destination data in the destination table is switched to the data corresponding to the common memory. In the loop control system, during execution, the destination table is referred to, the switching data in the common memory corresponding to the destination data is received, and one round of execution is performed according to this, and the destination data is simultaneously transferred to the other side. Switch to data corresponding to common memory.

When another switching data is sent from the sequence control device while the loop control system makes one round, this switching data is stored in the other common memory according to the destination data in the destination table, and the destination data is also switched. The destination data whose destination is this common memory is not referenced while the loop control system makes one round, so the loop control system executes based on the same switching data, and when the loop ends, the new destination data is Based on the data, other switching data will be received.

(Example) An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a control system to which the present invention is applied. In this embodiment, a step sequencer 1 as a sequence control device and a plurality of controllers 7 constituting a loop control system. ... are connected via the common memory section 2, and remote/local switching (hereinafter referred to as "rR/L switching") of the setting values of the controllers 7 and 8 can be performed in steps via the common memory section 2. This is done using switching data from the equation sequencer 1.

First, in the figure, the step sequencer 1 is shown.

Two types of switching data for R/L switching: rR/L■' and r
R/L■'', and these switching data are alternately selected as the sequence control shifts to each step 'SxJ+rsz', .

Further, 2 is a common memory section, and this shared memory section 2 is a first memory section that stores switching data rR/L■J, rR/L■.
and second common memories 3 and 4, a destination table 5 for writing switching data from the step sequencer 1 to the common memories 3 and 4, and controllers 7 and 8, which will be described later.
A destination table 6 is provided for reading switching data from the common memory 3.4 as a destination.

Furthermore, the controllers 7 and 8 that constitute the loop control system in the process are for controlling the opening and closing of the control valve 9, for example. By switching to the local side ("R" in the figure) or the local side ("L" in the figure), it is possible to individually adjust the set value of the valve opening/closing amount remotely or on the spot. Note that 12 and 13 each indicate an adjustment switch.

Next, this operation will be explained with reference to FIG.

First, in step S1, the step sequencer 1 stores, for example, switching data rR/L in the first common memory 3 via the destination table 5, and at the same time, the unfinished data in the destination table 6 is stored in rOJ. Switch.

Now, it is assumed that this incomplete data rOJ corresponds to the first common memory 3. In the figure, ti is the execution time of one step.

As a result, the loop control system refers to the destination table 6 when starting one round of execution, and each controller 7.8 uses the switching data rR/R/R stored in the common memory 3 corresponding to the unfinished data "0". The receiver picks up "L■" and operates the 0 internal switching switch 11 in the R/L switching section to perform R/L switching. At the same time, the loop control system updates the destination data in the destination table 5 with "
1".

It is assumed that this destination data "1" corresponds to the second common memory 4.

Next, when the step of the step sequencer 1 shifts to S2 as shown in the figure during the time t2 when all the controllers constituting the loop control system complete one cycle of execution, the switching data in this step S2, e.g. rR/L■'' is stored in the second common memory 4 according to the destination data ``1'' of the destination table 5. On the other hand, since the unfinished data in the destination table 6 referred to by the loop control system when starting execution is rOJ, all the controllers 7, 8, etc. switch from the first common memory 3 during time t2. It operates according to the data rR/L■.

When time t2 has elapsed and the execution of the next round is started, steps are transferred several times within the previous time t2, and the final step Sn-□ corresponds to the switching data "R/L■" Suppose that it was something to do. In this case, when the execution of the next round starts, the unfinished data in the destination table 6 is "1" as shown in the figure, so the loop control system transfers the switching data rR/L from the second common memory 4. R/L
The 0 internal switching switch 11 in the switching section is operated to perform R/L switching and to switch the data in the destination table 5 to "0".

Hereinafter, in the same way, the loop control system only refers to the destination data of the destination table 6 at the time when one round of actual r starts,
During that period, execution is performed based on the same switching data, so
Even if the switching data is updated from the step sequencer 1 within the period, all controllers 7. f is operated according to the same switching data.

(Effects of the Invention) As described above, according to the present invention, a common memory is provided;
During execution of the loop control system, even if new switching data is updated from the sequence control device, this data is kept on standby in one common memory. controllers, etc. can be controlled based on the same data.

Therefore, it is possible to change the setting values etc. during the cycle.
- It is possible to perform layer-accurate loop control.

[Brief explanation of the drawing]

Figure 1 shows an embodiment of the present invention. Figure 1 shows a schematic configuration of a control system to which the present invention is applied, and Figure 2 is a timing chart showing the operation. ...Step type sequencer 5 2...Common memory section 3, 4...Common memory 5...Destination table 6...Destination table 7.8...Controller 10...R/L switching Department and patent applicant Fuji Electric Co., Ltd.-1J (1 other person) Shima Wholesale

Claims (1)

[Claims] In a method of switching data used for loop control via a memory in accordance with transition of steps by a sequence control device, the memory in which switching data is stored and selected according to destination data is provided. A loop control system comprising: first and second common memories, a destination table in which destination data is switched by execution of a loop control system, and a destination table in which destination data is switched in accordance with step transition by a sequence control device; executes one cycle according to the switching data in one common memory that corresponds to the destination data referenced when starting the execution, and at the same time corresponds the destination data in the destination table to the switching data in the other common memory. A control method for switching data in a loop control system characterized by switching to destination data.