JPH0224419B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a communication device, and particularly to a control device between communication devices.

[Prior art]

A conventional device of this type is shown in FIG. Figure 1 shows the configuration for communication between two communication devices 1 and 3.
1 is a controller as one communication device, 50 is a first control device provided to directly control communication with the controller 1, and 3 is another communication device that communicates with the controller 1. wireless device as, 6
0 is a second control device provided to perform communication control over the wireless device 3 via the wireless circuit 5;
2 is a wireless device of this second control device 60.
A wire 4 is provided between the first control device 50 and the second control device 60, thereby forming a wire communication path A. Also 6a,
Reference numeral 6b is a signal line for exchanging communication signals and transmission activation signals.

Next, the operation will be explained. A communication signal and a transmission activation signal sent from the controller 1, which is one communication device, pass through the signal line 6a, via the wire 4 of the wired communication path A, and then through the signal line 6b of the second control device 60. , is received from the wireless device 2 via the wireless circuit 5 to the wireless device 3, which is the other communication device. Conversely, the communication signal transmitted from the wireless device 3 is received by the controller 1 of the first control device 50 through a reverse path of the above-mentioned communication path.

Since the conventional device is configured as described above, the first control device 50 and the second control device 60 must be electrically connected by the wire 4, and the wire may be disconnected due to external factors. If something like that happens, communication will become impossible. In addition, if the control device is installed on top of a mountain, it is susceptible to natural disasters, and if the wire 4 above is disconnected and communication becomes impossible, it will take a lot of time to find the disconnected point and repair it to restore communication. There were drawbacks such as:

[Summary of the invention]

This invention was made in order to eliminate the drawbacks of the conventional ones as described above, and it provides a wireless communication path as well as a wired communication path between control devices, and detects when the wire in the wired communication path is disconnected. It is an object of the present invention to provide a communication device that can eliminate a communication failure state and enable stable communication by automatically switching to the above wireless communication channel when the line is disconnected.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings. In FIG. 2, the same reference numerals as in FIG. 1 indicate the same parts. 70 is a first control device, and in this first control device 70, 7 is a first wireless device, and 8 is a first control circuit, which connects the controller 1 and the first wireless device 7 or a wired It has a function of switching and connecting the wire 9 and a function of detecting disconnection of the wire 9. C is a relay provided in this first control circuit 8 to detect disconnection of the wire 9, and c1
is the contact point of relay c. Further, 80 is a second control device, and in this control device 80, 10
11 is a second wireless device, and 11 is a second control circuit, which has the function of switching and connecting the third wireless device 2 and the second wireless device 10 or the wired wire 9, and detecting disconnection of the wired wire 9. It has the following functions. D is this second
This is a relay provided in the control circuit 11 for detecting disconnection of the wire 9, and d1 is a contact point of the relay D. 6c and 6d are signal lines. The first control device 70 and the second control device 80 are
It is electrically connected by a wire 9.

Next, the operation will be explained.

First, when the wire 9 is normally connected, that is, when there is no disconnection, the relay contacts c1 and d1 of the control circuits 8 and 11 are tilted toward the side shown by the solid line in FIG. 2. In such a state, the communication signal and transmission activation signal sent from the controller 1, which is one of the communication devices, are transmitted from the signal line 6a to the relay contact c1 of the control circuit 8 to the wire 9 of the wired communication path A to the second The relay contact d1- of the control circuit 11 of the control device 80 of
The signal is received by the wireless device 3, which is the other communication device, through the signal line 6b--third wireless device 2--radio circuit 5 path. Conversely, the communication signal transmitted from the wireless device 3 is
The signal is received by the controller 1 through a path opposite to the above-mentioned path. In this case, transmission activation of the first wireless device 7 and the second wireless device 10 is prohibited.

Next, if wire 9 is disconnected for some reason,
Each relay contact c of the first and second control circuits 8 and 11
1, d1 falls to the side shown by the broken line in FIG. Therefore, the communication signal and transmission start signal sent from the controller 1 are transmitted from the signal line 6a to the relay contact c of the control circuit 8.
1-First wireless device 7-Wireless communication path B-Second wireless device 10 of second control device 80-Control circuit 11
The signal is received by the wireless device 3 through the relay contact d1 - the signal line 6b - the third wireless device 2 - the wireless circuit 5. Conversely, a communication signal transmitted from the wireless device 3 is received by the controller 1 through a reverse route to the above route.

Here, the third wireless device 2 and the second wireless device 1
Mutual exchange of transmission activation at 0 is performed only when relay contact d1 is connected. Therefore, in the case of no connection, the second wireless device 10
Activation of transmission is prohibited.

Further, the first control circuit 8 and the second control circuit 11 are connected to each other when the first control device 70 and the second control device 80 are normally interconnected by the wire 9, and when the wire 9 is disconnected. It has a function to detect when interconnection is no longer possible, and a function to switch signal lines.

The operation of both control circuits 8 and 11 will be explained as follows.
Relay C and relay D of both control circuits 8 and 11 are in an operating state with a normal bias voltage induced,
In this state, the contacts c1 and d1 of each relay C and D are connected to the wired communication path A side (the state shown by solid lines in FIG. 2). When the wire 9 is disconnected, the normal bias voltage is no longer induced in the relay C and the relay D, and the contacts c1 and d1 are connected to the wireless communication path B side (the state shown by the broken line in FIG. 2).

Note that when the wired communication path A is restored, the wireless communication path B is automatically restored to the wired communication path A.

In the device of this embodiment, when the wire 9 is disconnected, the relay C of each control circuit 8, 11
D detects it and automatically switches the communication path between the respective control devices 70 and 80 from wired communication path A to wireless communication path B, so recovery work until finding and repairing the wired disconnection point is possible. It is possible to eliminate communication failure even in the middle of the day, and stable communication can be maintained at all times.

In the embodiments described above, disconnection detection and signal line switching in each control circuit are performed using relays, but this is not necessarily limited to relays.

〔Effect of the invention〕

As described above, according to the communication device according to the present invention, when communicating between two communication devices, the first
A wireless communication path is configured in addition to a wired communication path between the control device and the second control device, and when the wired communication path is disconnected, this is detected and switched to the wireless communication path. Even if a wired communication path becomes unusable due to a wire breakage, a wireless communication path can be secured, and stable communication can be achieved at all times.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a communication device, and FIG. 2 is a block diagram of a communication device according to an embodiment of the present invention. 7, 10... Wireless device, 8, 11... Control circuit, 9... Wired line, 5... Wireless line, 70, 80...
...Control device, A...Wired communication path, B...Wireless communication path. In the figures, the same reference numerals indicate the same or equivalent parts.

Claims (1)

[Claims] 1. A first control device provided on one communication device side to directly control communication to the device, and a first control device provided on the other communication device side to control communication to the device via a wireless line. a second control device, the communication device performs communication between both of the communication devices, wherein a wired communication path is provided between the first and second control devices; The control device has first and second wireless devices each having a wireless communication path therebetween, and the first and second control devices each detect a disconnection in the wired communication path, and when the disconnection is detected, It is characterized by having first and second control circuits that switch the communication path between the two control devices to the wireless communication path and, after the wired communication path is restored, switch the communication path to the wired communication path. Communication device.