JPH0310961B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a controller that performs process control using a microprocessor.

As shown in Figure 1, this type of conventional controller has the following features:
The microprocessor 11 controls the multiplexer 12 to switch the measurement signal from the process field from the terminal 13 and the setting signal, which is the control target, from the terminal 14, and input them into one input side of the comparator 15.
The digital signal output from the microprocessor 11 to the DA converter 16 is converted into an analog signal, the analog signal is supplied to the other input side of the comparator 15, and the output of the comparator 15 is connected to the microprocessor 11. By the input operation, the measurement signals and setting signals at the terminals 13 and 14 are converted into digital signals and input into the microprocessor 11. In this way, the measurement signal and setting signal are taken in, the deviation between them is determined, so-called adjustment calculations such as proportional, integral, and differential are performed on the deviation, and the calculation results are sent to the DA converter 16.
The converted analog signal is sampled and held in the holding means 18 by the switch 17, and the held output is sent to the output terminal 2 through the output buffer 19.
1 to the process field as a control signal. The control signal at the terminal 21 can be input to the microprocessor 11 via the multiplexer 12 and the comparator 15 as required. The microprocessor 11 can output various signals such as measurement signals, setting signals, control signals, and deviation signals to the display 22 for display. Various parameters necessary for calculation are set in advance for the microprocessor 11 by the parameter setting means 23.

Further, a manual setting means 24 is provided, and with the mode switch 25 set to the manual M side, an increase switch 26 and a decrease switch 27 are manually operated to increase or decrease the content held in the holding means 18 by the manual operation means 24. Can be done. Microprocessor 11
reads whether the manual operation switch 25 is switched to the manual side M or the automatic side A, and executes automatic control or suspends the control. In addition, the microprocessor 11 exchanges data with a higher-level device through an interface 28 with a transmission path.
It can also be operated manually through. In other words, the controller operation can be switched between local mode and remote mode, or between automatic mode and manual mode in each mode.

In this conventional controller using a microprocessor, if the microprocessor 11 fails and the automatic operation state is specified, the automatic control will not be performed as expected, and manual control will also be performed. A situation arises where there is no such thing. Further, if the local mode specification and the remote mode specification conflict, confusion may occur.

SUMMARY OF THE INVENTION An object of the present invention is to provide a controller that, when a conflict occurs between the local mode specification and the remote mode specification, gives priority to the preferred mode between the two specifications, so that control is not confused.

According to this invention, the remote mode designation signal and the local designation signal are input to the priority processing circuit, and the operation mode is determined according to these input signals. For example, a local manual operation designation signal has priority over a remote mode designation signal. Also,
If necessary, manual operation in local mode allows control over the control signals to be carried out through the microprocessor, and when the microprocessor switches between automatic and manual mode, the processing within the microprocessor Once you are ready, you can move on to the switched operation. Furthermore, a signal indicating whether the microprocessor is normal or abnormal is also input to the priority processing circuit, and an operation mode is designated according to the state of this signal. For example, an absolute manual operation means that does not go through the microprocessor is provided, and the absolute manual operation mode is set when the microprocessor is abnormal.

FIG. 2 shows an example of a controller according to the present invention,
Components corresponding to those in FIG. 1 are given the same reference numerals. In this invention, a priority processing circuit 31 is provided, and each mode designation signal is inputted to this priority processing circuit 31 from a local mode manual operation designation switch 33 and an absolute manual operation designation switch 37. Further, the designated states of the local mode automatic operation designation switch 32 and manual operation designation switch 33 are input to the microprocessor 11 through signal lines 34 and 35, respectively. Further, a remote mode designation signal, that is, a signal indicating a mode for performing manual operation or automatic operation from a remote location through the interface 28, is input from the microprocessor 11 to the priority processing circuit 31 through the signal line 36.

Remote operations are performed via an operator's console of a computer system with communication capabilities, and are the responsibility of an operator stationed at the remote location.

Further, manual operation in the local mode is carried out under the responsibility of the local operator who monitors the controller, and in this embodiment, it is carried out through the microprocessor 11, and the increase switch 26 and decrease switch 27 are It is also connected to the microprocessor 11.

Furthermore, an absolute manual operation designation switch 3 is provided in case the controller goes into unexpected operation due to a communication failure, etc., and this designation signal is input to a priority processing circuit 31. A signal indicating the selected operation mode of the priority processing circuit 31 is connected to the signal line 38.
The signal is supplied to the microprocessor 11 through the microprocessor 11.
The manual operation means 24 is enabled to operate only when a predetermined signal is generated from the output line 39 of the priority processing circuit 31.

A signal indicating whether the microprocessor 11 is normal or abnormal is input to the priority processing circuit 31 through a signal line 41.

The priority processing circuit 31 is configured as shown in FIG. 3, for example. That is, one end of each of the switches 32, 33, 37 is grounded, and the other end of each of the switches 32, 33, 37 is connected to the inverter 42, 4.
3, 44 and resistors 45, 4.
6 and 47, respectively, to the positive power supply terminal 48. Each output side of the inverters 42, 43 is connected to the microprocessor 11 via signal lines 34, 35 as shown in FIG.

Note that the inverters 42, 43, and 44 in FIG. 3 are used to make the on/off states of the switches 32, 33, and 37 correspond to the levels 1 and 0, and have no special meaning in terms of the logical configuration.

A signal indicating absolute manual operation from the inverter 44 and a signal indicating whether the microprocessor 11 is normal or abnormal from the signal line 41 are input to a NOR circuit 51, and the output side of the NOR circuit 51 is a flip-flop consisting of a NAND circuit. 52 is connected to the set input side. When controlling the control signal through the microprocessor 11, a signal indicating this is applied to the reset input of the flip-flop 52 through an inverter 53. flipflop 5
The set output of 2 is supplied to the manual operation means 24 in FIG. 2 through a signal line 39, and the signal on the signal line 39 and the outputs of the inverters 43 and 53 are inputted to the AD circuit 54 with their polarities inverted. . The output of the AND circuit 54 is input to the microprocessor 11 through the signal line 38.

Figure 4 shows the correspondence between signal states and events that occur due to operator operations, remote transmission, failures, etc. The numerical values in the figure are for each switch and figure in Figures 2 and 3. It corresponds to the code of the signal line.

The priority processing operations in FIGS. 2 and 3 will be explained using combinations of the 1 level and 0 level states of each signal.

FIG. 5 summarizes the logical output values indicated by signals 39 and 38 as priority processing solutions when each signal summarized in FIG. 4 is at 1 level or 0 level. In FIG. 5, the state shows the case where the signal 41 is 1. The explanation will be as follows in relation to the logic diagram of FIG.

Based on the 1 level of the signal 41, the gate 51 makes its own output 0 level regardless of the level of the signal 93. Flip-flop circuit 52 responds only to the 0 level signal from gate 51 and sets the level of output 39 to 1 regardless of other signals.
That is, since the NAND gate in the circuit 52 that provides the output 39 is a gate that makes the output 39 zero only when all of the inputs are 1, in response to a 0 level from the gate 51, a 1 is sent to the output 39. It responds to output the level. The gate 54 is a gate that receives three inputs in an inverted manner, and has an inversion symbol ◯ on its input portion.

That is, since the gate 54 is a gate that outputs a 1 level to the output 38 when all inputs are 0 level, it acts in response to the 1 level of the signal 39 to make the signal 38 a 0 level. Therefore, in the state shown in FIG. 5, only one level of the signal 41 causes the signal 3 to become
The solution to 9,38 is given. The situation in FIG. 5 shows that the level of signal 93 provides a solution for signals 39 and 38 regardless of the levels of the other signals. The 1 level of the signal 93 in this state is treated as an input to the gate 51 in the same way as the previous signal 41, and thus provides the same solution as the previous signal 41.

In the states shown in Fig. 5, 3a, 3b, ..., the local manual operation switch 33 is turned on and the signal 3 is
This shows a solution when the level of signal 38 is set to 1, and indicates that the level of signal 38 is set to 0 regardless of signals 34 and 36.

In other words, if the level of signals 41 and 93 is 0 and the level of signal 35 is 1, then solutions 38 and 39 are 0 regardless of whether the levels of signals 34 and 36 are 0 or 1.
The state of 3a indicates that the level of signals 41 and 93 is 0, 35
When the level of is 1, it means that the level of signal 34 is 0 or 1, and when the level of 36 is 0, the solutions 38 and 39 are 0 level, and the state of 3b means that the level of signals 41 and 93 is 0. , 35
When the level of the signal 34 is 1, this indicates that even when the level of the signal 34 is 0 or 1, and the level of the signal 36 is 1, the solutions 38 and 39 are also at the 0 level.

Also, the state of , is the signal 41, 93, 3
This shows that if any of 5 collides, solution 39 becomes level 1.

Similarly, the status is remote signal 3.
This shows that when the level of signal 6 is 1, the solution of signal 38 is 1 level.

The above understanding of the theory shows the following situation.

(b) For abnormalities conveyed by signal 41, a manual decision is made with priority over others; (b) For absolute manual designation of signal 93, manual decision is given priority over others; (c) For signal 35, manual decision is given priority over others. For the designation of , a manual decision is made in preference to the automatic designation, and (2) for the manual designation conveyed by the signal 36, a manual decision is made in preference to the automatic designation of the signal 34.

Incidentally, the above-mentioned situation 2 is the state shown in Fig. 5,
, , and the details are as follows.

State is an example in which local automatic specification is performed by one level of signal 34, but solution 3
8 is provided by signal 36.

The status is automatic locally, manual remotely, and solution 38 is 0, which determines that automatic locally is not possible. In other words, the local automatic designation will not be adopted unless the remote is also automatic (this logic is realized by simply not inputting the signal 34 to the priority processing circuit in FIG. 3).

State , indicates that the solution 38 is provided by the remote 36 in the absence of a local specification.

When the absolute manual operation designation switch 37 is turned on, the output of the inverter 44 becomes a high level "1", which is applied to the flip-flop 52 through the NOR circuit 51, which is set and the signal line 39 becomes a high level "1". The manual operation means 24 shown in FIG. 2 becomes operable. Furthermore, when the microprocessor 11 becomes abnormal and the signal line 41 becomes high level "1", the flip-flop 52
is set and the signal line 39 goes high. Therefore, either the operator turns on the absolute manual operation switch 37 at the site, or the microprocessor 11
When an abnormality occurs, the manual operating means 24 can control the control signal of the output terminal 21 in FIG. 2 without passing through the microprocessor 11, and manually control the process.

In this case, the high level "1" on the signal line 39 shown in FIG. Receive the designation of

When the manual operation designation switch 33 is turned on,
This is notified to the microprocessor 11 through signal lines 35 and 38, and as shown in FIG. The control signal of the output terminal 21 is controlled accordingly. At this time, the microprocessor 11
The flip-flop 52 is reset by setting the signal line 36 to a high level.

When the local mode automatic operation designation switch 32 is turned on, this is notified to the microprocessor 11 through the signal line 34, and local automatic operation is performed only when the state of the switch 38 is at level 1.

In FIG. 2, a signal indicative of a remote manual mode command is transmitted from a remote location, such as a central control center, to the microprocessor 11 through an interface 28.
, the microprocessor 1 connects the signal line 38 to
The control signal of the output terminal 21 is controlled in accordance with the manual operation from a remote location by confirming that the state of is at a high level, that is, it is not an absolute manual operation or a local manual operation.

As can be understood from the above explanation, according to the priority processing circuit 31 shown in FIG. Priority is given to manual operation (on-site), followed by remote manual operation.

Therefore, according to the present invention, even if a plurality of operation mode specifications are given at the same time, the operation mode is determined according to the predetermined priority order, and there is no risk of confusion, and the desired operation mode is selected at that time. . Furthermore, when local manual operations are performed through the microprocessor 11 as in the embodiment described above, continuous control is performed when mutually switching between various operating modes, and there is no period during which control is interrupted.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a controller using a conventional microprocessor, FIG. 2 is a block diagram showing an example of a controller according to the present invention, and FIG. 3 is a specific example of the priority processing circuit shown in FIG. Circuit diagram showing an example, 4th
The figure is a diagram showing the correspondence between events occurring due to transmission, failure, etc. and signal states, and FIG. 5 is a diagram showing the logical output indicated by the priority processing solution. 11... Microprocessor, 12... Multiplexer, 13... Measurement signal input terminal, 14...
Mixed signal input terminal, 15... Comparator, 16...
DA converter, 19... Output buffer, 21... Control signal output terminal, 22... Display device, 23... Parameter setting means, 24... Manual operation means, 26,
27...Manual operation switch, 28...Communication line interface, 31...Priority processing circuit, 32
...Automatic operation designation switch, 33...Manual operation designation switch, 37...Absolute manual operation designation switch.

Claims (1)

[Claims] 1. A local automatic operation designation switch 32 that designates automatic control mode, a local manual operation designation switch 33 that designates manual control mode, and a communication line that remotely designates automatic control or manual control mode. It inputs measurement signals and setting signals, performs adjustment calculations, and outputs control outputs, and specifies the mode of the local automatic operation designation switch 32, manual operation designation switch 33, and communication line interface 28. The microprocessor 11 to which each mode signal is supplied from the means, the local manual operation designation switch 33, the communication line interface 28, the absolute manual operation designation switch 37, and the microprocessor 11 are checked for normality or abnormality. inputting a signal indicating the selected operation mode, determining the priority, and outputting a signal indicating the selected operation mode to the microprocessor 11;
A priority processing circuit 31 outputs a signal indicating a manual operation mode to the manual operation means 24 only when a predetermined signal is generated, and the priority processing circuit 31 minimizes abnormalities in the microprocessor 11. output as priority, then output a mode signal from the absolute manual operation designation switch 37, then output a mode signal in priority order of local manual operation, then remote manual operation, and then output the mode signal from the absolute manual operation designation switch 37, in order of priority, The means 24 is the microprocessor 1
A controller characterized in that it is configured to output a manual control signal instead of the controller.