JPS60120401A - Process controller - Google Patents

Abstract

PURPOSE:To perform bumpless switching of gain automatically by allowing controllers to perform the tracking operation of the output of a driver not only in a manual control mode but also at a non-selected time. CONSTITUTION:The output of a common operator 10 is inputted to a controller 20A through a contact (h) of an input tracking command changeover switch 40A and is inputted to a controller 20B through a contact (h) of a changeover switch 40B. When a gain selecting command 40 outputs a level ''1'' gain selecting command, switches 40A and 40B are switched to the contact (h) and a contact O (earth potential) and a switch 50 is switched to a contact A. When changover switches 40A and 40B are switched to contacts O, a tracking command is supplied to controllers 20A and 20B. Thus, controllers 20A and 20B different in gain are connected to the operator through said changeover switches 40A and 40B, and the mode of controllers 20A and 20B is switched to the tracking mode at a non-selected time to track the output of a driver 40.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to gain switching of a process control device capable of gain switching.

FIG. 1 is a configuration diagram of a conventional example of a single gain process control device, where ① is an operating device, 2 is a PID operation controller, 3 is a
is a driver, and 4 is a control valve.

The operating device 1 sends a target value to the controller 2 in the automatic control mode A, but directly inputs the manipulated variable adjusted by the operator to the driver 3 in the manual control mode M. In this manual control mode, the driver 3 and the controller 2 are electrically disconnected by an interlock circuit 31 in the driver 3, but the controller 2 is configured to trunk the output of the driver 3. That is, when the manual control mode M is selected, the electromagnetic relay 21 that gives the trunking command is excited, and the output of the driver 3 is fed back to the tracking circuit 22 in the controller 2. Therefore, when the control mode is switched from the manual control mode M to the automatic control mode A, the switch can be made bumpless without affecting the output of the driver 3.

Figure 2 is a block diagram of a conventional process control device with multiple gains.
is the same type of controller as controller 1, and 20A and 20B are controllers 2
30 is the same type of driver as the driver, and 10A, 2OA, JOB, and 20B share the driver 30 to form control systems A and B with different gains, respectively, and control Systems A and B are selected by a gain selection switch 50 that receives a gain selection command from a gain selection command device 40.

In this configuration, for example, when switching from control system A to control system B, control system B is once set to manual control mode M and the output of control system A is tracked, then the gain selection changeover switch 50 is switched, and control system B By setting automatic control mode A, it is possible to prevent jumps from occurring in the driver output.

However, to change the gain, you must manually switch the +al operator, (b) operate the gain selection switch, (C
) Since it requires operations such as automatically switching the operating device, there are problems in that it places a heavy burden on the operator, there is a risk of erroneous operation, and it is expensive because only one operating device is needed.

[Summary of the invention]

This invention was made in view of the above-mentioned conventional problems, and allows the controller to perform driver output tracking operation not only in manual control mode but also in non-selection, so that the controller can be operated when switching gain selection. The present invention proposes a process control device that does not require manual operation, can switch gains automatically without bumping just by giving a gain selection command, and requires only one operating device.

[Embodiments of the invention]

FIG. 3 is a block diagram showing one embodiment of the present invention. In the figure, reference numeral 10 indicates a common operating device, and its output is sent to the controller 2°A via the contact of the incoming car tracking command changeover switch 40A, and via the contact of the human car tracking command changeover switch 40B. Controller 20
B has been away for a long time. The input-trunking command changeover switches 40A and 40B switch to contact ON and contact O (ground potential), respectively, when the gain selection command unit 4o outputs a level gain selection command, and when it outputs a 0-level gain selection command. Switches between contact 0 (ground potential) and contact 1, respectively. In addition, the input-trunking command changeover switch 40A
, 40B switches to contact 0, a tracking command is supplied to the controllers 2OA and 20B. When the gain selection switch 5° receives Lebel's gain selection command, it changes to contact A.
When receiving a 0 level gain selection command, each switch is switched to contact B.

In this configuration, the control system B including the controller 20B is now
is selected, the gain selection changeover switch 5 is connected to contact B, the long-tracking command changeover switch 40A is connected to contact 0, and the input-tracking command changeover switch 4. OB has been switched to contact mode. Therefore, the output of the driver 3° corresponds to the output of the controller 20B, and the controller 2OA receives the trunking command and outputs the output from the driver 3°.
It is in tracking mode to track the output of °. In this state, when a gain selection command (Level) for selecting control system A is given from the gain selection command device 4o, the gain selection changeover switch 5o changes to contact A, and the large cart ranking command changeover switch 40A changes to contact. , input −
The trunking command changeover switch 40B switches to contact 0, and the controller 20kl><operator 1 replaces the controller 20B.
0 and the driver 30. At this time, the controller 20A
Since the output of the driver 30 is tracked, gain switching is performed bumplessly without causing a jump in the output of the driver 30. This time, since the controller 20B is in the tracking mode for tracking the output of the driver 3o, the switching from the control system A to the control system B is also bumpless.

In the above embodiments, contact switches are used as the gain selection switch and the input-tracking command switch, but it goes without saying that non-contact switches such as analog switches may also be used.

Further, although the above embodiment describes a case where there are two control systems to be switched, the present invention can be practiced and similar effects can be obtained even when there are three or more control systems.

〔Effect of the invention〕

As explained above, this invention has a configuration in which each of the controllers with different gains is connected to an operating device via an input-tracking command changeover switch, and when not selected, the controller switches to tracking mode and tracks the driver output. This makes it possible to automatically perform gain bumpless switching simply by issuing a gain selection command, which reduces the burden on the operator compared to conventional methods, eliminates the risk of erroneous operation, and improves operation efficiency. Since only one device is required, an inexpensive process control device can be obtained.

[Brief explanation of drawings]

1 and 2 are block diagrams showing a conventional process control device, and FIG. 3 is a block diagram showing an embodiment of the present invention. In the figure, 10-operator, 20A, 20B-controller, 30-driver, 4 (L-gain selection command device,
40A, 40B-Manpower-1~Racking command changeover switch, 50-Gain selection changeover switch. In addition, in the figures, the same reference numerals indicate the same or corresponding parts. Agent Masuo Oiwa

Claims (1)

[Claims] (1) [An actuator, a controller that receives target input from the actuator, a driver that converts the level of the manipulated variable output from the controller and outputs it to the control valve, a driver that converts the level of the manipulated variable output from the controller and outputs it to the control valve; Alternatively, the process control device has a function of inputting a manually adjusted operation amount to the driver, and the controller tracks the driver output for bumpless switching between manual and automatic control modes, and the gain is changed. In a device comprising a plurality of controllers with a gain selection command, and a gain selection changeover switch that selectively connects the controllers with corresponding gains to a common driver based on a gain selection command, each controller has a power output according to the gain selection command. The controller is connected to the operating device via an input-tracking command changeover switch that operates based on the tracking command, and other controllers other than the selectively connected controller receive the tracking command and execute the tracking of the driver output described in 1. Characteristic process control equipment.