JPS6313541A - Data bypass circuit - Google Patents

Abstract

PURPOSE:To bypass a data transmission line by using an output of a fault detection circuit of a slave station so as to control a relay circuit having a contact opening or short-circuiting a bypass circuit thereby disconnecting a transmission/reception circuit of a faulty station automatically from the data transmission line. CONSTITUTION:If a fault takes place in a transmission/reception circuit 31 in a slave station 21, a fault detection circuit 41 uses a detection signal to control a relay control circuit 51 thereby turning off e power supply of a relay circuit 61. The relay circuit 61 brakes its contact with power supply ON to open a bias circuit of a data transmission line 7. In this case, a data from the circuit 31 is sent to the transmission/reception circuit of the next slave station 22 via the transmission line 7. On the other hand, the relay circuit 61 opens the signal line from the circuit 31 to the line 7 with the power supply turned off to short-circuit the bypass circuit of the data transmission line. Thus, the data transmission line bypassing the station is constituted automatically and no hindrance is given to the data transmission between other normal slave stations 22,23 and a master station 1.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention provides a data bypass circuit, particularly in data transmission between a master station and a plurality of slave stations, when a failure occurs in any slave station, the faulty station is The present invention relates to a data bypass circuit that allows data transmission at a fault-free station by bypassing the data.

[Conventional technology]

Conventionally, in data transmission between a master station and multiple slave stations,
If a failure occurs in any slave station.

Data transmission between parent and child stations has been carried out by manually operating a switch or the like to change lines.

[Problem that the invention seeks to solve]

In the conventional method described above, it is first necessary to detect a faulty station, and furthermore, because of manual switching, it takes a long time for data transmission lines to be down, and it takes a lot of manpower and time to secure two lines.

Additionally, if a failure occurs in a slave station that causes it to constantly output data due to a transmitting/receiving circuit failure, a data collision will occur between the master station and all slave stations, making data communication impossible. There was a drawback.

The following margin [Means for solving the problem] The data bypass circuit of the present invention performs data transmission between a master station and a plurality of slave stations, and when a failure occurs in any of the slave stations, the data bypass circuit bypasses the failed station. The system includes a relay circuit having a contact that opens or shorts the bypass circuit by turning on and off an applied voltage, a detection circuit that determines whether there is a fault in a slave station, and the relay circuit based on the output of the detection circuit. and a relay control circuit that controls the relay control circuit.

〔Example〕

The present invention will be explained using the drawings.

FIG. 1 is a block diagram of a data bypass circuit according to an embodiment of the present invention. 1 in the figure is the master station.

Child station 21. , 22 and 23 are connected via data transmission lines 7 and 8.

They are connected so that data can be transmitted from the master station to the slave station, and from the slave station to the master station.

That is, when the slave stations are normal, data from the master station 1 is transmitted to the slave stations 21 , 22 , and 23 via the transmission path 7 .

Each data from the slave station is sent to the master station via the transmission line 8.

Now, consider a case where a failure occurs in the transmitting/receiving circuit 31 in the slave station 2. The failure detection circuit 41 is connected to the transmitting/receiving circuit 31.
Detects the occurrence of a fault in the relay control circuit 5 based on the detection signal.
1 and turns off the power to the relay circuit 61.

When the power is turned on, this relay circuit breaks the contact and opens the bypass circuit of the data transmission line 7. At this time, data from the transmitter/receiver circuit 31 is transmitted to the transmitter/receiver circuit of the secondary slave station 22 via the transmission line 7. On the other hand, when the power is turned off, the relay circuit opens the signal path from the transmitting/receiving circuit 31 to the transmission path 7, and short-circuits the data transmission path by creating a bypass circuit.

Due to this operation, when a transmitting/receiving circuit of a certain slave station fails, the transmission path from the circuit to the data transmission path is disconnected.
A data transmission path that bypasses that station is automatically configured, and there is no problem in data transmission between other normal slave stations and the master station.

In addition, since the relay circuit has a break contact to bypass the transmission line, a similar bypass circuit can be configured even when the power of the slave station is cut off or when the transmitter/receiver circuit panel is not installed. .

〔Effect of the invention〕

As explained above, the present invention does not have any effect on other slave stations when a failure occurs in the transmitter/receiver circuit of a slave station, when the station power supply goes down, or when the transmitter/receiver circuit is disconnected. There is an effect that the data transmission path can be bypassed by automatically disconnecting the transmitting/receiving circuit of the failed station from the data transmission path without causing any trouble.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a data bypass circuit according to an embodiment of the present invention. In the figure

Claims (1)

[Claims] 1) When data is transmitted between a master station and multiple slave stations and a failure occurs in any of the slave stations, the bypass circuit is opened by turning the applied voltage on and off in the transmission system that bypasses the failed station. a relay circuit that has contacts that cause short-circuiting or short-circuiting, and a detection circuit that determines whether or not there is a fault in the slave station;
A data bypass circuit comprising: a relay control circuit that controls the relay circuit based on the output of the detection circuit.