JPH0573132A - Erroneous mounting detection device for output module for digital control - Google Patents

Abstract

(57) [Summary] [Purpose] In order to prevent accidents, it is possible to detect in advance that an output module of a different type from the normal one is erroneously attached to the output stage of the digital controller. A control unit of a digital control device for outputting a check signal of H level or L level; mounted on an output stage of the digital control device, and inputting a check signal from the control unit of the digital control device as an operation signal An output module for outputting; and a determination unit that determines that the mounting output module is erroneously mounted based on the fact that the output of the mounting output module differs from the output of the regular output module in terms of signal level.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an output module for digital control capable of detecting in advance that an output module of a different type from the normal one is erroneously attached to the output stage of a digital control device and preventing an accident. Erroneous mounting detection device.

[0002]

2. Description of the Related Art A conventional digital controller is shown in FIG.
Will be described with reference to. In FIG. 3, a digital control device (hereinafter, referred to as a control device) 20 mainly includes a deviation device 8, a control unit 2, and an output module 3. The state quantity of the controlled object 9 is sent to the deviation device 8 via the detection unit 7, and the deviation from the target signal So is taken here. The deviation signal is input to the control unit 2, and its output is converted into an operation signal by the output module 3. This operation signal acts on the controlled object 9 via the operation unit 6. By repeating the above cycle, control is performed so that the deviation becomes zero.

The output module 3 is a unit that is detachably attached to the output stage of the control device, and is roughly classified into an NPN type or a PNP type, and either type is selected according to the control system. FIG. 4 is a block diagram of the NPN type output module. In the figure, the NPN type output module 31 is an NP.
The N-type transistor 11 is used as an input stage, the collector side of which is connected to Vcc through the pull-up resistor R on the one hand and the input side of the level conversion circuit 13 on the other side. Therefore, the NPN type output module 31 outputs the H level signal from the output side of the level conversion circuit 13 in response to the input of the H level signal.

FIG. 5 is a block diagram of a PNP type output module. In the figure, the PNP output module 32 is a PN
Using the P-type transistor 12 and the NPN-type transistor 11 as input stages, the emitter side of the PNP-type transistor 12 is directly, the collector side of the NPN-type transistor 11 is Vcc via the pull-up resistor R, and the level conversion circuit 13 is also direct.
Connected to the input side of. Here, PNP transistor
The collector side of 12 and the base side of the NPN transistor 11 are connected. Therefore, the PNP type output module 32
Is output from the output side of the level conversion circuit 13 with respect to the input of the L level signal.

[0005]

In the conventional control device 20 shown in FIG. 3, it is very convenient in practice that the output module 3 is detachably attached to the output stage thereof. However, it is a problem if the selection is wrong at the same time.
In other words, not only the control becomes impossible or the device fails, but it may lead to the occurrence of an accident in the entire control system including the control target.

An object of the present invention is to solve the above problems of the prior art and to detect in advance that an output module of a different type from the normal one is erroneously attached to the output stage of the digital control device, resulting in an accident. It is an object of the present invention to provide an erroneous mounting detection device for an output module for digital control, which can prevent such a situation.

[0007]

According to a first aspect of the present invention, there is provided an erroneous mounting detection device for a digital control output module, comprising a control unit of the digital control device for outputting an H level or L level check signal; An output module which is mounted on the output stage of the digital control device and which receives a check signal from the control unit of the digital control device and outputs it as an operation signal; the output of the mounted output module differs from the output of the regular output module in terms of signal level. Based on this, the mounting output module includes a determination unit that determines that the mounting output module is erroneously mounted.

According to a second aspect of the present invention, there is provided an erroneous mounting detection device for a digital control output module, wherein the output module is an NPN type or a PNP type.

[0009]

In the erroneous mounting detection device for the digital control output module according to claim 1 or 2, in the detection mode, an H level or L level check signal is output by the control unit, and an actual mounting output in response to this is output. Based on the fact that the operation signal output from the module differs from the output from the regular output module in terms of signal level, the determination unit determines that the mounting output module is erroneously mounted.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an erroneous mounting detection device for a digital control output module according to the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of the embodiment. This embodiment is based on the digital control device of the conventional example, and is provided with a small number of additional units, and by switching the connection, it has a function of detecting an erroneous mounting of an output module. In FIG. 1, the additional units are a designation unit 1, a switching unit 4, and a determination unit 5. To be precise, the control unit 2 is also functionally slightly different from that in the conventional example, but is given the same reference numeral here. The designating unit 1 first designates switching of the automatic mode in which digital control is performed and the detection mode related to erroneous mounting to the switching unit 2, secondly, designates a check signal to the control unit 2, and thirdly. The determination unit 5 specifies the determination criteria for detection. Figure 1
In, the broken line indicates the signal flow in the detection mode, and the solid line indicates the signal flow related to normal digital control. Further, the area surrounded by the alternate long and short dash line constitutes the detection device 10 relating to erroneous mounting.

The operation of the embodiment will be described mainly with reference to the flow chart of FIG. 2 and supplementary reference to the block diagram of FIG. In FIG. 2, the detection mode is switched in step S1. Specifically, in FIG. 1, the mode switching designation from the designation unit 1 to the switching device 4,
Of the check signal to the control unit 2 of
The determination criteria for is specified respectively. In step S2, the output module M (output module 3 in FIG. 1) is mounted. When the regular output module is the NPN type in step S3, the check signal Sc to be output from the control unit 2 in step S4 becomes an H level signal (hereinafter referred to as H signal). In the next step S7,
The determination unit 5 determines whether or not the output Sm of the output module that is actually attached, that is, erroneous attachment should be detected, is the H signal. If Sm: H, it is determined in step S8 that the attachment is correct, and Sm is If different from H, step S1
At 0, the mounting is determined to be incorrect.

Returning again to step S3, where the regular output module is not of NPN type, ie step S5.
In the case of the PNP type, the check signal Sc to be output from the control unit 2 becomes the L signal in step S6. Thereafter, the process proceeds to step S7, and the same procedure as described above is taken. Now, if it is determined that the mounting is correct in one step S8, the series of detection operations is ended after switching to the control mode in step S9. On the other hand, if it is determined in the other step S10 that the mounting is incorrect, the mounting of the output module M is changed in step S11, the process returns to the previous stage of step S3, and the same determination is repeated.

[0013]

In the erroneous mounting detection device for the digital control output module according to the first or second aspect of the present invention, in the detection mode, the control unit outputs the H-level or L-level check signal, and the actual signal is received. The determination unit determines that the mounting output module is erroneously mounted based on that the operation signal output from the mounting output module differs in signal level from the output of the regular output module. Therefore, since it is possible to detect in advance that the output module has been erroneously attached, proper control can be guaranteed and accidents due to erroneous attachment can be prevented. Moreover, since the means therefor is simple, the detection can be performed quickly and the cost increase can be small.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment according to the present invention.

FIG. 2 is a flowchart showing the operation of the embodiment.

FIG. 3 is a block diagram showing a configuration of a conventional control device.

FIG. 4 is a block diagram of an NPN output module.

FIG. 5 is a block diagram of a PNP output module.

[Explanation of symbols]

 1 Designating Part 2 Control Part 3 Output Module 4 Switching Device 5 Judgment Part 6 Operation Part 7 Detecting Part 8 Deviation Device 9 Control Target 10 Judgment Device

Claims (2)

[Claims] 1. A control unit of a digital control device for outputting a check signal of H level or L level; mounted on an output stage of the digital control device and receiving a check signal from the control unit of the digital control device. An output module that outputs as an operation signal; and a determination unit that determines that the mounting output module is erroneously mounted based on the output of the mounting output module being different from the output of the regular output module in terms of signal level; An erroneous mounting detection device for an output module for digital control, characterized by: 2. An erroneous mounting detection device for an output module for digital control according to claim 1, wherein the output module is an NPN type or a PNP type.