JP3278068B2 - Controller - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a controller used for controlling a process and the like, and more particularly to a controller capable of directly inputting a signal from a sensor installed in a process and maintaining the controller. The present invention relates to a controller capable of monitoring a process at the time of a failure or a failure and backing up an operation signal output to a process (field) without interruption.

[0002]

2. Description of the Related Art Conventionally, a single-loop controller using a microprocessor has been widely put into practical use. Such a single-loop controller is a distributed control system (DC
Compared with S), there is an advantage that the engineering burden is small and the operability is good. The conventional single-loop controller has an operation panel on the front face thereof which displays information necessary for control (process amount PV and control output MV), as shown in, for example, Japanese Patent Publication No. 57-57721. An operation key for changing a set value and an operation key for changing an adjustment mode (automatic adjustment mode, manual adjustment mode, etc.) are arranged, and a signal input to the controller is a standard such as 1 to 5V. It was configured on the premise that the converted process amount was input. When such a controller is to be maintained, or when the controller is out of order for some reason, a backup device (manual operation device) for outputting an operation signal is used. The apparatus is configured to input a standardized signal (process amount PV) and adjust or operate the manual operation signal so as to stabilize the manual operation signal while monitoring the process amount PV. .

[0003]

As described above, the conventional controller uses a signal converter (or a signal converter) for converting a signal from a sensor installed in a process (field) into a standardized signal (or a unified signal). The signal conditioner is configured to be applied via a signal conditioner, and a signal conditioner must be prepared separately from the controller. For this reason, there has been a problem that an instrumentation panel becomes large and wiring and the like become complicated. Further, there is a problem that a device for backing up a controller cannot be used in combination with a controller that directly handles a signal from a sensor. The present invention has been made in view of these points,
Signals from sensors installed in the field (field sensor signals other than unified signals) can be directly input. Even if such field sensor signals are input, maintenance of the controller and An object of the present invention is to provide a controller that can be used in combination with a backup device in the event of a failure.

[0004]

According to the present invention, there is provided a controller provided with an inner unit having a control operation unit and a case for accommodating the inner unit. To
A signal conditioner for converting a field sensor signal other than the unified signal from the sensor into a standardized signal is provided, and in the case, a pair of sensor inputs for directly applying a signal from the sensor to the signal conditioner. Terminals, external terminals from which signals from the signal conditioner can be derived, and unified standardized control and operation units
At least a pair of process amount input terminals to which a signal from a signal conditioner led to the external terminal via a lead wire or a process amount signal which is a signal is applied, and a signal from the control operation unit is output via a diode. Operation signal output terminal, and an external connector for taking out at least the process amount input terminal and a signal applied to the operation signal output terminal to the outside of the case, and a process amount signal or the signal conditioner outside the case. This is a controller characterized in that a signal from the controller can be monitored.

[0005]

When a sensor that outputs a signal other than the unified signal is directly connected to the controller, the sensor is connected to the sensor input terminal. Also, a lead wire is connected between the external terminal and the process amount input terminal. In this case, the signal from the sensor enters a signal conditioner provided in the internal unit, where it is converted into a unified signal and output to an external terminal. The unified signal output to the external terminal is applied to the process amount input terminal via a lead wire, and is input to the control operation unit provided in the internal unit. The unified signal is taken out of the case via the external connector.

[0006]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a configuration block diagram showing one embodiment of the present invention. This figure illustrates a case where a backup device (manual operation device) is connected to the controller.
In the figure, reference numeral 1 denotes a controller, and a portion surrounded by a dashed line assumes that case. Reference numeral 2 denotes a controller internal unit accommodated in the controller case 1, which includes a printed board on which a main electric circuit of the controller is mounted. 3 is a process amount PV and a control target value S which are standardized unified signals.
A control operation unit which inputs V and performs, for example, PID control operation and outputs the operation result to the process as an operation signal MV, and is constituted by a microprocessor. Reference numeral 4 denotes a display provided on the front panel of the controller, for example, a full dot liquid crystal display capable of displaying characters and graphics in a mixed manner is used. Reference numeral 5 denotes a display control means,
, For example, independent of a microprocessor. The display control means 5 inputs a process amount PV, a control target value SV, an operation signal MV, and the like handled by the control operation unit 3 during a normal control operation, and transmits various operation information necessary for the control operation and its monitoring. Control for displaying on the display 4 is performed. The display control means 5 has a function for creating various screens to be displayed on the display 4 and various operation keys K1 to K10 provided on the front panel of the controller.
And has the function of transferring the signal to the control operation unit 3 and reflecting the signal on the information displayed on the display 4.

Reference numeral 6 denotes a signal conditioner for converting a signal from the sensor into a standardized signal and supplying the converted signal to the control operation unit 3, which also includes a microprocessor and a memory. , Which can handle signals from various sensors. The signal conditioner 6 can be attached to and detached from the internal unit 2. Reference numeral 7 denotes a signal conditioner (SC) maintenance means for displaying information necessary for setting the function of the signal conditioner 6 on the display 4 under the operation of the display control means 5;
The signal conditioner 6 has a function of setting a predetermined function corresponding to the type of sensor directly connected to the controller based on a signal from the operation key.

In Case 1, reference numerals 11 and 12 denote a pair of sensor input terminals to which a signal from a sensor SNR installed in the field is directly applied, and the signal applied thereto is guided to an input terminal of a signal conditioner 6. ing. 13
Is an external terminal to which the output terminal of the signal conditioner 6 is connected, and 14 and 15 are a pair of process quantity input terminals to which a process quantity PV, which is a standardized unified signal, is applied. The quantity PV is the control calculation unit 3
Is applied to the input terminal of Reference numerals 16 and 17 denote operation signal output terminals to which an operation terminal VA such as a valve is connected.
It is output via 1. Although not shown, the output terminals 16 and 17 can output a signal from a manual operation device provided in the controller internal device as necessary. C
C1 is an internal connector for making an electrical connection between each terminal provided in the case 1 and an electric circuit in the internal unit 2, and is configured so that the internal unit 2 can be removed from the case. CC
Reference numeral 2 denotes an external connector provided on the case 1 so that signals applied to the process amount input terminals 14 and 15 can be taken out of the case 1. The external connector CC2 is connected not only to the process amount input terminals 14 and 15 but also to both ends of the diode 21 and operation signal output terminals 16 and 17, respectively.

Reference numeral 30 denotes a backup device which can monitor the process amount PV or the signal from the signal conditioner 6 outside the case 1, and is connected to the controller main body via an external connector CC2. In the backup device 30, reference numeral 31 denotes a process amount input terminal 14.
Is an operation signal output means for outputting a manual operation signal, and the operation signal output from the PV indicator 32 can be adjusted by an MV operation knob 33. Reference numeral 34 denotes an MV indicator for indicating a signal output from the operation signal output unit 32. The operation signal output means 32 is operable by power from a built-in battery, but is operated by receiving power supplied from a power supply line (not shown) to prevent the operation time from being limited by the operation time. It is like that. 35 is an operation signal output means 32
A switch for outputting the signal output from the control signal output terminal 16 to the operation signal output terminal 16. A switch 36 prevents the output from the control operation unit 3 provided in the internal unit 2 from being output to the operation signal output terminals 16 and 17. (Prohibit) switch, 2
The two switches 35 and 36 are configured to be driven synchronously by the backup changeover switch knob 37. Reference numeral 38 denotes a signal conditioner, which is detachably provided to the backup device 30. CC3 is an internal connector, and an internal connector CC1 provided in the internal unit 2.
The backup device 30 can be accommodated in the case 1 instead of the controller internal device 2. That is, when the internal unit 2 is pulled out of the case and the backup device 30 is stored in the case 1 instead, the sensor input terminal 1 is connected to the signal conditioner 38.
1 and 12 are provided, and a signal from a signal conditioner 38 can be output to an external terminal 13.

FIG. 2 is a conceptual view of the external appearance of the controller main body and the backup device 30. In the controller inner unit 2, the front panel including the display 4 can be swung up as shown in the drawing, and in this state, one of the external connectors CC2 appears at the back of the front panel, and the backup device 30 Connection is made possible. Although the controller inner device 2 including the display 4 is housed in the case 1 as shown in the figure, it can be removed from the case 1 by pulling it out from the case 1 in case of failure or maintenance. It has become. The backup device (manual operation device) 30 has a PV indicator 31, an MV indicator 34 arranged on a front panel thereof, and an MV operation knob 33 and a backup switch knob 37. Also,
Its outer shape is almost the same as that of the controller inner unit 2, and a signal conditioner 38 is provided near the rear part.
As shown in the figure, a pocket portion 39 that can be attached is prepared, and the signal conditioner 38 can be accommodated in the case 1 with the signal conditioner 38 attached. The backup device 30 is connected to the controller main body via the external connector CC2 and can operate even in a separated state as shown in the figure. However, the controller inner unit 2 is removed from the case 1 and provided on the inner unit 2. The signal conditioner 6 is removed, and the signal conditioner 6 is attached to the pocket portion 39 on the backup device 30 side.
Even if 0 is accommodated in the case 1, it can be used.

The operation of the apparatus having the above-mentioned configuration will be described below. First, when a standardized process amount PV composed of, for example, a 1 to 5 V signal is input to the controller, the standardized signal PV is applied to the process amount input terminals 13 and 14. On the other hand, when the sensor is directly connected to the controller (when a signal other than the standardized signal is input), the signal from the sensor SNR is applied between the terminals 11 and 12 and the external terminal 13 is connected to the process. A lead wire 20 is connected between the input terminal 14 and the quantity input terminal 14 as shown by a broken line. As a result, the sensor signal directly input from the sensor enters the signal conditioner 6 and is converted into a signal standardized here, which is output to the external terminal 13 and is connected to the lead wire 2.
0, through the process amount input terminal 14, is again applied to the control operation unit 3 in the internal unit 2. The control calculation result from the control calculation unit 3 is output to the operation signal output terminals 16 and 17 via the diode 21, and the operation terminal VA such as a valve is operated.
Sent to In such a control operation state by the control calculation unit 3, the process amount PV handled by the control calculation unit 3,
The values of the set value SV and the operation signal MV are displayed on the display control unit 5.
Is displayed on the display 4 as a bar graph or digital value. It should be noted that what kind of signal conversion processing is to be performed by the signal conditioner 6 depends on the types of sensors connected to the sensor input terminals 11 and 12 in advance by using the SC maintenance means 7 to transmit necessary information to the display 4. It is assumed that the display is set by the operation keys.

The controller main body is assumed to operate independently. However, when the internal unit 2 breaks down, or when the internal unit 2 is inspected and maintained, it is backed up by the backup device 30. In this case, the front panel of the controller is swung up as shown in FIG. 2, and the other external connector CC2b connected to the backup device 30 is connected to one of the external connectors CC2a appearing in the back. In the backup device 30, the backup switches 35, 3
6 is initially in an off state, and the insertion and removal of the external connector CC2 can be performed without affecting the operation of the controller internal device 2. When the external connector CC2 is connected, a signal applied to the process amount input terminals 14 and 15 (a signal from the signal conditioner 6 when the sensor is directly connected to the terminals 11 and 12) is supplied to the backup device 30.
Is applied to the PV indicator 31 via the buffer amplifier inside the
You can monitor here. At this time, the MV indicator 34 of the backup device 30
The output signal from is indicated.

In this state, when the backup changeover switch knob 37 is operated and the switches 35 and 36 are turned on (backup state), the output from the controller inner unit 2 (control operation unit 3) side is output from the switch 36. Instead, the output signal from the operation signal output means 32 is output to the field side via the switch 35 and the output terminals 16 and 17. Therefore, it is possible to switch to the backup state without momentary interruption of the operation signal output to the field side. At the time of switching to the backup state, the value of the output signal from the operation signal output means 32 (the value of the MV indicator) is converted into the controller internal unit 2 (control operation unit 3)
If a balance operation is performed to match the output value from the side (this value is displayed on the display 4 or displayed by an operation output indicator (not shown)), switching to the backup state is performed by the bumpless. it can. In the backup state, the MV operation knob is operated while monitoring the value of the operation signal output to the field side (operating end side) with the MV indicator 34 and monitoring the indication of the PV indicator 31.
The operating end can be operated manually. In the device of the present invention, even when such a manual operation in the backup state is performed by directly connecting the sensor to the controller,
There is one feature in that it can be performed while monitoring the V value.

FIG. 3 shows that the controller inner unit 2 is detached from the case 1, the signal conditioner 6 provided in the inner unit 2 is detached, and the signal conditioner 6 is attached to the pocket 39 on the backup device 30 side. FIG. 4 is a connection diagram of main parts showing a state in which the backup device 30 is housed in a case 1 instead of the internal unit 2. Even if the controller inner unit 2 is removed from the case in the backup state, the output signal from the operation signal output unit 32 is output to the field side, so that the process is not affected. When the backup device 30 is housed in the case 1, the case 1 and the backup device 30
The internal connectors CC1 and CC3 are connected as shown, and a signal from a signal conditioner 38 mounted on the backup device side is guided to the PV indicator 31. Therefore, even when the sensor is directly connected to the controller, the PV value can be continuously monitored by the PV indicator 31 on the backup device side. In this embodiment, a controller that handles one process quantity PV is illustrated, but two or more sensors may be directly connected,
The present invention may be applied to a controller that performs cascade adjustment or selector adjustment by inputting the above process amount.

[0015]

As explained in detail above, according to the present invention, a sensor can be directly connected to a controller.
The wiring can be simplified and the instrumentation panel can be made compact. In addition, even if the controller internal unit is removed from the case at the time of maintenance or failure of the controller to which the sensor is directly connected, backup (manual operation) should be performed while monitoring the PV value on the backup device side. Can be.

[Brief description of the drawings]

FIG. 1 is a configuration block diagram showing one embodiment of the present invention.

FIG. 2 is an external conceptual view of a controller main body and a backup device.

FIG. 3 is a connection diagram of main parts showing a state in which a backup device is housed in a case instead of the controller internal device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Controller case 2 Controller inner unit 3 Control operation part 4 Display 5 Display control means 6 Signal conditioner 7 Signal conditioner maintenance means 11, 12 Sensor input terminal 13 External terminal 14, 15 Process amount input terminal 16, 17 Operation Signal output terminal 20 Lead wire 21 Diode 30 Backup device 31 PV indicator 32 Operation signal output means 33 MV operation knob 34 MV indicator 35, 36 Switch 37 Backup changeover switch knob SNR sensor VA Operation terminal CC1, CC3 Internal connector CC2 External connector

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-63-141103 (JP, A) JP-A-59-8002 (JP, A) JP-A-58-76901 (JP, A) JP-A-58-76 151602 (JP, A) JP-A-3-116306 (JP, A) JP-A-1-72601 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) G05B 7/02 G05B 11 / 36 G05B 23/02

Claims (6)

(57) [Claims] 1. A controller comprising an internal unit equipped with a control operation unit and a case accommodating the internal unit, wherein the internal unit has a field sensor other than a unified signal from a sensor.
The capacitors signal provided signal conditioner for converting the normalized signal, to said casing, and a pair of sensor input terminals for applying a signal from the sensor directly to the signal conditioner, from said signal conditioner And at least one pair of processes to which a signal from a signal conditioner led to the external terminal via a lead wire or a process quantity signal which is a unified signal standardized by the control operation unit is applied. An operation signal output terminal through which a signal from a control operation unit is output via a diode; at least the process amount input terminal ; and the operation signal output
A controller provided with an external connector for extracting a signal applied to a terminal to the outside of a case, so that a process amount signal or a signal from the signal conditioner can be monitored outside the case. 2. The controller according to claim 1, wherein the signal conditioner provided in the inner unit is detachably provided to the inner unit. 3. The internal unit is configured to make an electrical connection to each terminal provided on the case via a detachable internal connector, so that the internal unit can be removed from the case. The controller according to claim 1, wherein 4. A backup device connected to an external connector, the backup device comprising: a process amount indicating means for indicating a signal applied to a process amount input terminal; and a manual operation signal via a manual changeover switch. 2. The controller according to claim 1, further comprising: an operation signal output unit for outputting; and an instruction unit for instructing an operation signal output by the operation signal output unit. 5. The backup device is configured to be housed in the case instead of the internal unit, and is electrically connected to each terminal provided on the case via a detachable internal connector. 5. The method according to claim 4, wherein
Controller. 6. The controller according to claim 4, wherein the backup device is configured so that the signal conditioner can be detachably attached.