JP3348185B2 - Connection unit drop detection method and programmable 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 method of detecting a disconnection of a connection unit in a penetrating type programmable controller constituted by connecting a plurality of units sequentially to a central processing unit , and a program for detecting the disconnection of a connection unit.
It relates to a gramable controller .

[0002]

2. Description of the Related Art Conventionally, in a programmable controller, as shown in FIG. 3, a plurality of units, for example, on / off information, are sent to a central processing unit (hereinafter referred to as a CPU unit) 10 for executing a predetermined program. Input / output unit (I / O unit) 20-
2. Description of the Related Art There is known a so-called penetrating type programmable controller which is configured by sequentially connecting 1 to 20-4 via a connector 20a.

[0003] This through-type programmable controller has a configuration without a motherboard.

[0004]

By the way, such a conventional programmable controller without a motherboard cannot detect this even if some of the connected units are dropped.

That is, since the penetrating type programmable controller can be arbitrarily connected regardless of the slot of the motherboard, the number of connected units in the CPU unit cannot be known. Therefore, neither the number of normally connected units nor the number of units after the unit has been dropped can be recognized by the CPU unit, no error occurs, and as a result, the dropped unit cannot be detected. .

Therefore, in this type of feed-through type programmable controller, even if a part of a normally connected unit is dropped, the operation is continued as it is. In this case, the safety of the programmable controller is reduced. descend.

If the programmable controller continues to operate in a state where it cannot detect that a part of the unit has been dropped, there is a possibility that a user may output unexpectedly depending on the program of the CPU unit, which is very dangerous. .

For example, in the case of a machine using a certain output as a start switch of a motor or the like, there is a risk that the machine may be destroyed or the operator may be damaged by the machine due to unexpected machine operation.

In view of the above, the present invention provides a method of detecting a detachment of a connection unit, which can reliably detect a partial detachment of a unit in a penetrating type programmable controller .
And a programmable controller that detects the disconnection of the connection unit
It is intended to provide a controller .

[0010]

To achieve the above object, according to an aspect of, the invention of claim 1, wherein a sequential plurality of units to the central processing unit for executing a predetermined program connector
In a through-type programmable controller configured to be connected in series via a controller, when connected to the last unit of the plurality of sequentially connected units,
Both stand at the end of the initial processing of the above multiple units
The central processing unit using the flag as an end detection signal
Connect the terminal dedicated unit to be transmitted to the terminal, return the flag set at the end of the initial processing of the plurality of units by the terminal dedicated unit , transmit the flag as a termination detection signal to the central processing unit, and terminate at the central processing unit. When the detection signal cannot be detected, the central processing unit detects that a part of the plurality of units has dropped out. According to a second aspect of the present invention, there is provided a penetrating type programmable controller configured by sequentially connecting a plurality of units in series via a connector to a central processing unit that executes a predetermined program. most of the plurality of units
The central processing unit is connected to the last unit, and includes a terminal dedicated unit for transmitting a flag set at the end of the initial processing of the plurality of units as a terminal detection signal to the central processing unit. ,
In a case where the terminal detection signal transmitted from the terminal-only unit cannot be detected, there is provided a unit drop detection unit that detects that a part of the plurality of units has dropped. According to a third aspect of the present invention, there is provided a penetrating type programmable controller configured by sequentially connecting a plurality of units to a central processing unit that executes a predetermined program in series via a connector . In addition to providing a line that crosses units,
A dedicated terminal unit connected to the last unit was provided, and the central processing unit passed through the above line.
It is characterized in that a unit drop detecting means is provided for detecting a signal from the terminal-only unit of the plurality of units and the terminal-only unit, and detecting that a part of the unit has dropped if the signal cannot be detected. And Claim 4
According to the invention described in the above, the unit drop detection means is configured to detect the end detection signal.
When the central processing unit detects a signal,
Executing a user program, and detecting the unit dropout
If the terminal cannot detect the termination detection signal,
The arithmetic processing unit stops operation.
You.

[0011]

According to the present invention, the flag set at the end of the initial processing of each unit is turned back by the terminal dedicated unit and transmitted to the central processing unit as a terminal detection signal, and the central processing unit cannot detect this terminal detection signal. In this case, it is detected that some of the plurality of units have been dropped.

According to such a configuration, in the penetration type programmable controller, it is possible to reliably detect that a part of a plurality of units have been dropped by a very simple configuration in which only a flag set at the end of the initial processing is monitored. And safety can be improved.

[0013]

EXAMPLES Hereinafter, the connection unit falling detection method according to the present invention, and programmers for detecting the detachment of the connection unit
An embodiment of a bull controller will be described in detail with reference to the drawings.

FIG. 1 shows an embodiment of a programmable controller constructed by applying the method of detecting a connection unit dropout according to the present invention. In FIG. 1, this programmable controller is a CPU unit 10
And a plurality of input / output units (I / O units) 20-
1, 20-2 are sequentially connected via a connector 20a. At the end of the plurality of I / O units 20-1 and 20-2, a termination dedicated unit 30 is provided.
Is connected.

The terminal-only unit 30 includes a plurality of I / Os.
It has a function of returning a flag set at the end of the initial processing of the O units 20-1 and 20-2 and transmitting it to the CPU unit 10.

The flag turned back by the terminal only unit 30 is transmitted to the CPU unit 10 as a terminal detection signal of the entire programmable controller system.

The CPU unit 10 is provided with a unit drop detector 11 for receiving the end detection signal and detecting the drop of the unit. The unit drop detector 11 detects the end detection signal at the end of the initial processing. Then, it is determined that the unit has not fallen off, and if the end detection signal cannot be detected, it is detected that the unit has fallen off. When the unit drop detector 11 detects that the unit has dropped,
Based on the drop detection output of the unit drop detector 11, C
The operation of the PU unit 10 is stopped. Further, in this state, the occurrence of unexpected output is prevented by outputting an error, and the device user is notified of the abnormality.

According to such a configuration, a situation in which an output unexpected by the user is generated is reliably prevented, and the safety of the device can be improved.

FIG. 2 is a flowchart showing the above operation.

That is, first, a plurality of I / O units 2
Initial processing of 0-1 and 20-2 is performed (step 10
1) When this initial processing is completed, the CPU unit 10
The unit drop detector 11 monitors the end detection signal returned by the end dedicated unit 30 and checks whether or not the end detection signal is detected (step 101). Here, when the terminal detection signal returned by the terminal-only unit 30 is detected, it is determined that the unit does not fall off, and the CPU unit 10 executes the user program (step 103).

However, if the terminal detection signal returned by the terminal-only unit 30 cannot be detected in step 102, it is determined that the unit has fallen off, and the operation of the CPU unit 10 is stopped (step 10).
4) A predetermined abnormality is displayed (step 105), and the user is notified that the unit has been dropped.

[0022]

As described above, according to the present invention,
The flag set at the end of the initial processing of each unit is looped back by the terminal-only unit and transmitted as a terminal detection signal to the central processing unit. If the central processing unit cannot detect this terminal detection signal, a Since it is configured to detect that the unit has dropped, it is possible to reliably detect the drop of the unit regardless of the number of connected units, and it is possible to reliably prevent a situation in which an output unexpected by the user is generated, There is an effect that the safety of the device can be improved.

[Brief description of the drawings]

FIG. 1 is a diagram conceptually showing an embodiment of a programmable controller configured by applying a connection unit drop detection method.

FIG. 2 is a flowchart showing an operation of the programmable controller shown in FIG. 1;

FIG. 3 is a diagram conceptually showing a conventional penetration type programmable controller.

[Explanation of symbols]

Reference Signs List 10 Central processing unit (CPU unit) 11 Unit drop detector 20-1 to 20-4 Input / output unit (I / O unit) 20a Connector 30 Termination only unit

──────────────────────────────────────────────────続 き Continuation of front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G05B 19/04-19/05

Claims (4)

(57) [Claims] A plurality of units are sequentially connected via a connector to a central processing unit which executes a predetermined program.
In a feed-through type programmable controller configured by connecting to a row, the last unit of the plurality of units connected in sequence is
Unit and the initial
A flag that is set at the end of processing is used as the end detection signal.
A terminal-dedicated unit to be transmitted to the central processing unit is connected, a flag set at the end of the initial processing of the plurality of units is turned back by the terminal-dedicated unit, and transmitted as a termination detection signal to the central processing unit. If the processing unit fails to detect the termination detection signal, the central processing unit detects that some of the plurality of units have been dropped, and the central processing unit detects this. 2. A plurality of units are sequentially connected via a connector to a central processing unit which executes a predetermined program.
In a through-type programmable controller configured by connecting to a row, the last unit of a plurality of units connected in sequence
And a dedicated terminal for transmitting a flag set at the end of the initial processing of the plurality of units to the central processing unit as a terminal detection signal, wherein the central processing unit includes the terminal dedicated A programmable controller, comprising: a unit drop detecting unit that detects that a part of the plurality of units has dropped when a termination detection signal transmitted from the unit cannot be detected. 3. A plurality of units are sequentially connected via a connector to a central processing unit which executes a predetermined program.
In a through-type programmable controller configured by connecting to a row, a line is provided across the plurality of units from the central processing unit, and the last unit of the plurality of units sequentially connected
The termination special unit which is connected to provided a central processing unit, has passed through the line above
Among the plurality of units and the terminal- only unit, a signal from the terminal-only unit is detected, and if the signal cannot be detected, unit drop detection means for detecting that a part of the unit has dropped is provided. Programmable controller. 4. The apparatus according to claim 1, wherein the unit drop detecting means is a terminal detecting signal.
When the central processing unit detects a signal,
Execute the user program, The unit drop detection means cannot detect the end detection signal.
The central processing unit performs operation.
Stop, The programmable according to claim 2 or 3, wherein
controller.