JPH0272410A - Programmable controller - Google Patents

Abstract

PURPOSE:To avoid the discontinuation of the entire working of a system when an I/O unit is replaced and at the same time to give no adverse influence to other I/O units by adding the cut-off switches to a power supply line and a signal transmission line set between a control unit and an I/O unit. CONSTITUTION:A cut-off switch 13a is set on a feed line 8 led to an I/O unit 5 within a control unit 10. At the same time, a cut-off switch 13b is set on a control signal transmission line 21 led from the unit 5 for a computing element 17 which carries out a sequence program. When the unit 5 is replaced, both switches 13a and 13b work with the cut-off instructions given from a cut-off instruction switch 11 or a programming device 15. Thus the unit 5 can be replaced with the line 8 is kept as a hot line. Therefore other I/O units and the unit 10 can freely work without discontinuing the system operation. Furthermore other I/O units are never affected by the noises produced with replacement of the unit 5.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention provides an input/output (110) unit or module in a programmable controller main body (control D unit).
The present invention relates to a programmable controller that can be connected to a computer.

(Prior Art) Conventionally, in a set-type programmable controller and a set-type 110 device that can be added to the set-type programmable controller via an extension cable, itl Ot of the programmable controller
When replacing a 110 unit or module that comes into contact with the L unit, there are two commonly known methods: a non-live method in which the power supply to the control unit is cut off, and a live method in which the replacement is performed without turning off the TL source. .

(Problem to be solved by the invention) However, as shown in FIG. Since the power supply 1a is commonly supplied, when replacing the T10 unit 5 of the collective programmable controller 6a, the power switch 2a must be turned off, and as a result, the entire system must be stopped (town). There is a problem with not being able to do so.

In addition, in the live line system as shown in Fig. 4, a power switch 2b, 2c is provided for each device, and each device has a power switch 2b, 2c.
, lc is supplied, in order to replace the I10 unit l-5 of the programmable controller 6a,
Even if the control unit 3 of the programmable controller 6a is operating properly, the power switch 2b must be turned off to stop the control units 1~. As a result, there is a problem that the collective I10 device 6b added to the programmable controller 6a also becomes in a signal output holding/stopping state, an output not holding/stopping state, or becomes deaf.

In the case of the latter live-line system, the status and condition of power being supplied to the additional T10 unit 5 and the additional T10
If the T10 unit 5 of the programmable controller is replaced while the unit 5 is exchanging signals with the control unit 3, electrical stress may occur due to the noise U in the logic circuit in the added Ilo unit 5. , a problem may occur in which the signals exchanged with the control unit 3 are disturbed. Therefore, the T10 unit 5 requires a signal processing circuit to eliminate the problem that occurs when replacing another I10 unit 5.

Therefore, the purpose of the present invention is to solve such problems,
To provide a programmable controller that does not stop the entire system and does not adversely affect other I10 units when replacing an I10 unit.

(Means for Solving the Problems) In order to achieve such an object, the present invention provides a control unit that performs arithmetic processing and one or more input/output units that input/output signals exchanged between the control unit and external equipment. has an output unit, and the input/output unit is 115 to the control unit.
In a programmable controller that can freely install two input units and can add input/output units, a first cutoff switch provided at the original power supply X spring from the second control unit to the input/output unit, and A second cutoff switch installed on the signal transmission line between the input/output unit, the first cutoff switch, and the second cutoff switch are turned off for 24 hours before removing the input/output unit 1. It is particularly characterized in that it comprises an instruction means for instructing.

[For production]

In the present invention, when replacing an input/output unit, the power supply line between the input/output unit and the control unit is cut off according to instructions from the instruction means, so other input/output units and control units can operate, and the system There is no need to stop. Furthermore, since the signal transmission lines between the input/output unit and the control unit are also cut off, the noise generated due to the replacement of the input/output unit will not adversely affect other input/output units.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 shows the circuit configuration of an embodiment of the present invention.

In FIG. 1, the same parts as in the conventional example shown in FIG. 4 are denoted by the same reference numerals, and detailed explanation thereof will be omitted.

:t, II fall within unit lO, I10
A cutoff switch 13 is placed on the power supply line 8 to the unit 5.
A is provided. Further, a cutoff switch 13b is provided on the signal transmission line 21 from the I10 unit 5 to the arithmetic unit 17 that executes the sequence program.

i! ! ! A cut-off instruction to the cut-off switch 13a and the cut-off switch 13b is issued by turning on the cut-off instruction switch 11 via the OR circuit 14. In addition to the cut-off instruction switch 11, a programming device 15 for manually inputting a sequence program is connected to the OR circuit 14 via a register 12, and a cut-off instruction can also be issued from the programming device 15.

In such a configuration, when replacing the I10 unit 5, the operator can switch the cutoff switch 13a based on a cutoff instruction from the cutoff instruction switch 11 or the programming device.
, 13b will operate, so leave the power supply line live and connect I.
10 units 5 can be replaced.

FIG. 2 shows a circuit configuration of a second embodiment of the present invention.

In FIG. 2, the same parts as in the first embodiment shown in FIG.

In FIG. 2, the output signal of the OR circuit 14 is input to an AND circuit 16. Also, the AND circuit 16 is connected to the arithmetic unit 1 based on the cutoff instruction stored in the data memory 18.
The cutoff instruction signal outputted from 7 is also manually input, and the output signal from the AND circuit 16 cuts off the cutoff switches 13a and 13b. On the other hand, the level state of the output signal of the AND circuit 16 is displayed on the display 19.

In this embodiment, any of the programming device 15, the cutoff instruction switch 11, and the arithmetic unit 17 can be used as a cutoff switch!
This is an example in which a shutdown instruction can be given to 3a and 13b.

Next, the operation of the tree\example will be explained.

When replacing the 110 unit 5, the operator sends a command to turn on the cutoff permission signal 17a to the computing unit 17 from the programming device @15 using a signal bus (not shown). Based on this transmission command, data memory 1
8 stores whether the cutoff signal is on. The arithmetic unit 17 holds and outputs the ON shutoff permission signal 17a to the AND circuit 16 based on the ON information of the shutoff permission signal in the data memory 18, similar to the conventionally known sequence program execution process.

Next, when the operator sends an on-off instruction signal from the programming device 15 to the register 12, the register holds and outputs the on-off instruction signal. As a result, the output level of the AND circuit 16 is turned on, so that the cutoff switches 13a and 13b are turned off (opened).

On the other hand, it goes without saying that after the cutoff permission signal 17a is turned on, the cutoff switches 13a and 13b are also turned off by the cutoff instruction switch 110 turned on and the cutoff instruction from the calculator 17.

The following can be considered as the usage pattern of this embodiment.

(1) When replacing the I10 unit 5, after the cutoff switches +3a and 13b are cut off, the cutoff permission signal 17a and cutoff instruction No. 43 14a are kept on according to instructions from the programming device 15. As a result, the cutoff switches 13a and 13b are interlocked to the cutoff state, so power is not supplied to the power supply line of the I10 unit 5 that is being replaced due to the operator's erroneous operation of the cutoff instruction switch 11, and the operator's replacement work is prevented. safety will be significantly increased.

(2) Shutdown permission signal 17 by programming device 15
If a is instructed to turn OFF, the AND circuit 16 will not accept the cut-off instructions from the cut-off instruction switch 11, the programming device 15, and the arithmetic unit 17. Therefore, even if the operator accidentally operates the cutoff switch 11 when the I10 unit 5 is normally operating normally, the I10 unit 5
10 Unit 5 never stops.

Next, the following can be considered as an application form of the embodiment of the present invention.

In this embodiment, regarding a programmable controller called a collective type in which a plurality of I10 units are modularized and connected to a control unit, the entire modularized I10 unit 5 is disconnected from the power supply line and signal line of the system.
Although the above example is shown, the power supply line and signal line to each I10 unit 5 may be cut off.

Furthermore, since semiconductor switches are used as the cutoff switches 13a and 13b of this embodiment, they do not include mechanical elements like relay switches, which increases the reliability of cutoff and makes it easy to interface with the logic system of the control unit 3. There are advantages to having one.

(Effects of the Invention) As described above, according to the present invention, when replacing the input/output unit, the power supply line between the input/output unit and the control unit is cut off by the instruction from the instruction means.
The other input/output units and control unit (3[1) are operational and there is no need to stop the system.In addition, the transmission line of the input/output unit and control unit I (FE) is also cut off. Therefore, it is possible to obtain the effect that the noise generated due to the exchange of the input/output unit does not adversely affect other input/output units.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing the configuration of an embodiment of the present invention, FIG. 2 is a circuit diagram showing the configuration of a second embodiment of the present invention, and FIGS. 3 and 4 are circuit diagrams showing the schematic configuration of a conventional example. It is. la, 1b, 1cm Electric 7 source, 2a, 2b, 2c...Main call switch, 3...Control unit, 4...Additional cable, 5...I10 unit, 6a...Collective programmable controller , 6b・
... set form I10 device, 12... register, 11]a,! 3b... Cutoff switch, 14... OR circuit, 15... Programming device, 16... Ant circuit, 17... Counter, 18... Data memory, 19... Display device . Fu brother yo moon song 2 fire pu) 已 ig 1] D Turn? Figure 2

Claims (1)

[Scope of Claims] 1) A control unit that performs arithmetic processing and one or more input/output units that input/output signals exchanged between the control unit and external equipment, and the input/output unit is connected to the control unit. A programmable controller that is detachable from the controller and capable of adding an input/output unit, comprising: a first cutoff switch provided on a power supply line from the control unit to the input/output unit; and a second cutoff switch provided on the signal transmission line between the input and output unit and the first cutoff switch and the second cutoff switch before removing the input and output unit. A programmable controller comprising: instruction means for instructing.