JPH05145440A - Signal changeover device - Google Patents

Abstract

PURPOSE:To allow one signal changeover device to be used in common for active/standby changeover and for loopback circuit formation with respect to the signal changeover device selecting a communication control section of redundancy configuration for an active side or a standby side. CONSTITUTION:Loopback circuits 4-0, 4-1 are connected so that they are formed only when contacts 3-0, 3-1 of changeover relays 2-0, 2-1 selecting communication control sections 1-0, 1-1 of the redundancy configuration to the active side or the standby side are thrown to the position of the standby side. When a system switching signal is at '1' and loopback circuit forming signals LP0, LP1 are set to '0', the operation/inoperation of the changeover relays 2-0, 2-1 is controlled by relay drive circuits 5-0, 5-1, the contacts 3-0, 3-1 are switched to connect, e.g. the communication control section 1-0 to an external device 7 as the active side and to connect the communication control section 1-1 to the loopback circuit 4-1 as the standby side.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a signal switching device for switching a redundant communication control unit between a working side and a spare side.
There is known a system in which the communication control unit has a redundant configuration and, when a failure occurs on the working side, it is switched to the standby side to improve reliability. There is also known a configuration in which transmission data is looped back and received, and the reception data and the transmission data are collated to check the normality of the apparatus. It is desired to economically realize such a signal switching device for switching the working spare.

[0002]

2. Description of the Related Art A conventional signal switching device is shown in FIG.
31-0 and 31-1 are communication control units, 32-0, 32-1, 35-0, and 35-1.
Is a relay, 33-0, 33-1, 36-0, 36-1 is a contact, 34-0, 34-1 is a folding circuit, 37-0, 37
-1 is a driver, 38-0 and 38-1 are receivers, 39
Is an inverter. Although it is possible to use a switching element such as a transistor or a thyristor for signal switching, a signal switching device using a relay is generally adopted because a relay is superior in terms of reliability.

The system switching signal from the common section or the like is, for example, "1".
Then, the relay 32-0 operates, the contact 33-0 is switched to the illustrated position, and is connected to an external device such as a terminal device. On the other hand, since the system switching signal is inverted by the inverter 39, the relay 32-1 becomes inoperative, the contact 33-1 is switched to the position shown in the figure, and is disconnected from the external device. When the folding circuit formation signal on the 0-system side is "0", the relay 35-0 becomes inactive and the contact 36-0 is switched to the position shown in the figure, so that the external device and the communication control unit 31-0 are not connected to each other. , The driver 37-0 and the receiver 38-0 are connected to be the active system.

When the loopback circuit formation signal on the system 1 side becomes "1", the relay 35-1 operates, the contact 36-1 is switched to the position shown in the figure, and the loopback circuit 34-1 causes the driver 37-1.
And the receiver 38-1 are connected to each other, a loopback circuit is formed for the communication control unit 31-1, and the loopback circuit 34-1 loops back the transmission data. The normality can be confirmed.

When a failure occurs in the 0 system on the working side, the system switching signal from the common section is set to "0" so that the relay 32-0 does not operate and the relay 32-1 operates. By setting the loopback circuit forming signal of the system to "0", the 1st system becomes the active side and the 0th system is switched to the standby side. Therefore,
The reliability can be improved by duplicating the communication control units 31-0 and 31-1 with respect to an external device and by using the active backup switching system. Further, by folding back the transmission data by the folding circuits 34-0, 34-1, the communication control units 31-0, 31
It is possible to confirm the normality of -1.

[0006]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention The above-mentioned conventional signal switching device is provided with a switching relays 32-0, 32 for active spares.
-1 and relays 35-0 and 35-1 for forming a loopback circuit are used, and a relay 32- for active standby switching is used.
Although 0 and 32-1 are shown only for data, since a large number of contacts or relays are required for control signals, the number of relays is large, and it is possible to achieve compactness and economy. could not. It is an object of the present invention to achieve economic efficiency by using both the current spare switching function and the folded circuit forming function.

[0007]

A signal switching device of the present invention will be described with reference to FIG. 1. A switching relay for switching communication control units 1-0 and 1-1 having a redundant configuration between a working side and a standby side. The switching relays 2-0, 2 are connected by connecting the contacts 3-0, 3-1 of 2-0, 2-1 so that the folding circuits 4-0, 4-1 are formed only when switching to the spare side. -1 has a configuration in which it is used both for the current spare switching and for forming the folded circuit.

[0008]

The system switching signal is applied to the relay drive circuit 5-0 as it is or to the relay drive circuit 5-1 via the inverter 6. For example, when a system switching signal with the 0 system as the active side is applied, the relay drive circuit 5-0 causes the switching relay 2 to operate under the condition that the 0 system folding circuit forming signal LP0 is not applied.
-0 is operated to switch the contact 3-0 to the position shown in the figure, and the communication control unit 1-0 is connected to the external device 7. Further, in the 1-system, since the system switching signal is inverted by the inverter 6,
The relay drive circuit 5-1 does not operate the switching relay 2-1. Therefore, the contact 3-1 is switched to the illustrated position, the loopback circuit 4-1 is connected to the communication controller 1-1, and the normality can be confirmed by the loopback test at any time.

When a system switching signal for setting the 1-system as the active side is applied, the relay drive circuit 5-1 switches the switching relay 2-1 under the condition that the 1-system folding circuit forming signal LP1 is not applied.
Is operated, the contact 3-1 is switched from the illustrated position, and the communication control unit 1-1 is connected to an external device. Further, since the relay drive circuit 5-0 does not operate the switching relay 2-0, the contact 3-0 is switched from the illustrated position, the communication control unit 1-0 is disconnected from the external device, and the loopback circuit is provided. Four
-0 is connected. Therefore, system 1 is the active side,
The 0 system is switched to the spare side. In addition, folding circuit formation signal LP
When 0 and LP1 are added, the relay drive circuit 5-
0, 5-1 makes the switching relays 2-0, 2-1 inoperative,
The loopback circuits 4-0 and 4-1 can be connected to the communication control units 1-0 and 1-1, which enables the loopback test.

[0010]

FIG. 2 is an explanatory view of an embodiment of the present invention, showing a case of a duplex configuration in which a terminal device 17 is connected as an external device, 11-0 and 11-1 are communication control units, 12-0, 1
2-1 is a switching relay, 13-0a, 13-0b, 13-
1a, 13-1b are contacts, 14-0, 14-1 are folding circuits, 15-0, 15-1 are relay drive circuits, 16 are inverters, 18-0, 18-1 are drivers, 19-0, 1
Reference numeral 9-1 is a receiver, 20-0 and 20-1 are processors (CPUs), 21-0 and 21-1 are memories for programs and data, and 22 is a common unit.

The common section 22 for the 0-system and the 1-system applies a system switching signal to the relay drive circuits 15-0 and 15-1 to control the active preliminary switching between the 0-system and the 1-system. The processors 20-0 and 20-1 control the communication control units 11-0 and 11-1 of the respective systems to perform communication with the terminal device 17, and to communicate with a host device (not shown). It controls communication between them. The processor 20-0 adds the 0-system loopback circuit formation signal LP0 to the relay drive circuit 15-0, and the processor 20-1 adds the 1-system loopback circuit formation signal LP0.
1 is added to the relay drive circuit 15-1 to perform a loopback test of the respective communication control units 11-0 and 11-1.

Further, when the switching relays 12-0 and 12-1 are in the operating state, the contacts 13-0 and 13-1 are switch-connected to the terminal device 17 side, and in the non-operating state, the folding circuits 14-0 and 14-1.
In the case of the configuration of switching connection to -1, the relay drive circuit 15-
0, when the system switching signal from the common unit 22 is "1" and the loopback circuit formation signal LP0 from the processor 20-0 is "0", the switching relay 12-0 is operated to output the loopback circuit formation signal LP0. When is “1”, the switching relay 12
When the system switching signal is "0" and the system switching signal is "0", the switching relay 12-0 has a logical configuration that does not operate regardless of the loopback circuit forming signal LP0. Since the system switching signal from the common unit 22 is applied via the inverter 16 as well, the system switching signal from the processor 20-1 is provided with the loopback circuit formation signal LP1 from the processor 20-1. Is 0, the switching relay 12-1 is operated.

Contact 13 of switching relays 12-0 and 12-1
When -0a, 13-0b, 13-1a, 13-1b are in the illustrated state, the communication control unit 11-0 transmits data to the terminal device 17 via the driver 18-0 and the contact 13-0a. In addition, since the data from the terminal device 17 can be received via the contact point 13-0b and the receiver 19-0, the communication control unit 11-0 operates as the working side.

At this time, in the communication control unit 11-1, the driver 18-1 and the receiver 19-1 are connected via the folding circuit 14-1, so that the transmission data from the communication control unit 11-1 is The driver 18-1 is returned via the contact point 13-1a, the return circuit 14-1, the contact point 13-1b, and the receiver 19-1, and by comparing the received data with the transmitted data, the driver 18-1 and receiver 1
It is possible to confirm normality including 9-1.

In the above-mentioned embodiment, only the switching relay for data is illustrated for simplification, but even when RS-232C of the standard is used, for example, in addition to the transmission data and the reception data, the timing is changed. A switching relay for switching various control signals such as a signal, a transmission request signal, a transmission enable signal, and a reception carrier detection signal is required. Further, not only the duplex configuration but also one active spare device for a plurality of active devices to provide an n: 1 active spare switching system,
It is possible to use both the switching relay for the current spare switching and the switching relay for forming the folded circuit.

[0016]

As described above, according to the present invention, the contacts 3-0, 3-1 of the switching relays 2-0, 2-1 for switching the redundant communication control section between the working side and the standby side, Connection is made so that the folding circuits 4-0 and 4-1 are formed only when switching to the spare side, and the switching relays 2-0 and 2-1 are used both for the current preliminary switching and for forming the folding circuit. This makes it easy to reduce the number of switching relays and reduce the size, and because the number of switching relays is reduced, power consumption is also reduced, providing an economical signal switching device. There are advantages.

[Brief description of drawings]

FIG. 1 is a diagram illustrating the principle of the present invention.

FIG. 2 is an explanatory diagram of an example of the present invention.

FIG. 3 is an explanatory diagram of a conventional example.

[Explanation of symbols]

 1-0,1-1 Communication control section 2-0,2-1 Switching relay 3-0,3-1 Contact point 4-0,4-1 Return circuit 5-0,5-1 Relay drive circuit 6 Inverter

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Mitsunobu Yoshida 1015 Kamiodanaka, Nakahara-ku, Kawasaki-shi, Kanagawa Fujitsu Limited

Claims (1)

[Claims] 1. A redundant communication controller (1-0, 1-).
Switching relay (2- that switches 1) between the working side and the spare side
The contacts (3-0, 3-1) of (0, 2-1) are connected so that the loopback circuit (4-0, 4-1) is formed only when switching to the spare side, and the switching relay ( 2-0, 2-1) has a configuration in which it is used for both active spare switching and folding circuit formation.