JPH05235910A - Changeover system in redundancy system - Google Patents

Abstract

PURPOSE:To provide the changeover system in the redundancy system in which a receiver side uniquely implements automatic changeover to an error signal from a sender side on the occurrence of a fault with respect to the changeover system in the redundancy system having transmission lines in duplicate. CONSTITUTION:A transmitter 150 is provided with a pattern generating circuit 300 generating a signal of a prescribed pattern, 1st and 2nd transmission sections 100,200 are respectively provided with a pattern addition/error insertion section 500 adding a signal of a prescribed pattern being an output of the pattern generating circuit 300 to a main signal or replacing a prescribed part of the signal of a prescribed pattern added to the main signal with an error pattern when a fault takes place to a pre-stage circuit and sending the replaced signal, and a receiver 900 is provided with a pattern check/changeover section 120 selecting a transmission line so as to receive a signal from other transmission line when an error pattern is detected from a signal received from one transmission line and number of times of detection exceeds a prescribed value.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a switching system in a redundant system having a duplicated transmission line.

At this time, there is a demand for a switching system in a redundant system in which an error signal from the transmitting side is automatically switched by the receiving side when a failure occurs.

[0003]

2. Description of the Related Art Conventionally, when a failure occurs in a transmission line or a device in the preceding stage, the switching of the device and the transmission line from the working line to the backup line is performed by control from a control unit (not shown).

[0004]

As described above, when a failure occurs, conventionally, it has been a problem that the switching takes time because the control is conventionally performed via the control section. In addition, since the number of signal lines for transmitting and receiving data increases, there is a problem that the system configuration scale becomes unnecessarily large.

Therefore, an object of the present invention is to provide a switching system in a redundant system in which switching does not take time and the number of signal lines is small.

[0006]

The above problems can be solved by the structure of the apparatus shown in FIG. That is, in FIG. 1, the first and second transmitters 100 for transmitting the main signal to the respective transmission lines,
In a redundant system composed of a transmitting device 150 having 200 and a receiving device 900 connected to each transmission line and receiving the main signal sent from the transmitting device via each transmission line,
Reference numeral 300 denotes a pattern generation unit provided in the transmission device 150 and generating a signal of a predetermined pattern.

Reference numeral 500 is provided in the first and second transmitters 100 and 200, and a signal of a predetermined pattern of the output of the pattern generator 300 is added to the main signal and sent out, or a failure occurs in the circuit at the preceding stage. In this case, the pattern addition / error insertion unit replaces a predetermined portion of the signal of the predetermined pattern added to the main signal with an error pattern and sends it.

120 is provided in the receiving device 900, detects an error pattern for a signal received from one of the transmission lines, and outputs the error pattern when the number of detections of the error pattern exceeds a predetermined value. It is a pattern check / switching unit that switches to receive a signal from the transmission path.

[0009]

In FIG. 1, a pattern generating section 300 provided in the transmitting device 150 generates a signal of a predetermined pattern and adds it to the pattern adding / error inserting section 500 provided in the first and second transmitting sections 100 and 200. .. Then, the signal of the predetermined pattern is added to the main signal and transmitted to the transmission line. Further, when a failure occurs in the circuit in the preceding stage, a predetermined portion of the signal of the predetermined pattern added to the main signal is replaced with an error pattern and sent to the transmission line.

On the other hand, the pattern checking / switching unit 120 provided in the receiving device 900 detects an error pattern for a signal received from one of the transmission lines (for example, the active transmission line). , When the number of error pattern detections exceeds a specified value, the other transmission line (for example, a backup transmission line)
Switch to receive signals from.

As a result, the switching time can be shortened by performing the switching by the receiving device independently, and the signal wiring can be reduced because the command for switching control from the control unit need not be transmitted. .. This can be used for any redundant system having a duplicated transmission line, and it greatly contributes to the efficiency and performance improvement of the system.

[0012]

FIG. 2 is a block diagram showing the construction of an apparatus according to an embodiment of the present invention. FIG. 3 is a time chart for explaining the operation of the embodiment.

FIG. 4 is a flow chart for explaining the operation of the embodiment. The same reference numerals denote the same objects throughout the drawings. In FIG. 2, the transmitting side device mounts the main signal data from the circuit (not shown) in the preceding stage and the PN pattern signal (see FIG. 3B) output from the PN pattern generating circuit 3 into the current package 1. PN pattern addition circuit 4
To the main signal data as shown in FIG.
The N pattern signal is added and output, and added to the error insertion circuit 5.

Similarly, in the spare package 2, the main signal data from the preceding circuit (not shown) and P
The PN pattern signal output from the N pattern generating circuit 3 is input to the PN pattern adding circuit 6 mounted on the spare package 2 to add PN to the main signal data as shown in FIG.
The pattern signal is added and output, and then added to the error insertion circuit 7.

Now, it is assumed that a failure has occurred in a circuit (not shown) connected to the previous stage of the active package 1. Then,
Recognizing this by the control unit 8 installed in another package,
A control signal for inserting an error pattern into the PN pattern signal is sent to the error insertion circuit 5 mounted on the current package 1. The error insertion circuit 5 receives this control signal and inserts an error pattern as shown in FIG. 3B into the PN pattern signal of the output signals of the PN pattern addition circuit 4. In the example shown in (B) of FIG. 3, the error insertion circuit 5 inverts the phase from the predetermined clock position of the original PN pattern signal shown in (B) of FIG. This signal is sent to the working transmission line.

On the other hand, in the receiving side package 9 of the receiving side device, the PN pattern check circuit 10 receives a signal from the working transmission line to separate the main signal and the PN pattern signal, and the main signal is a separate circuit. (Not shown), and the PN pattern signal is compared and collated with a preset PN pattern signal (see FIG. 3B).

In the present case, since the error pattern is inserted in the received PN pattern signal, the two do not match, but the number of clocks that do not match is counted by the counter section 11 and the count value is set to a preset value N (eg, When the number reaches three, the signal indicating this is sent to the switching control circuit 12.
When the switching control circuit 12 receives this signal, it sends a switching signal to the PN pattern check circuit 10, and the PN pattern check circuit 10 switches from the current transmission path to the backup transmission path. After that, the PN pattern check circuit 10 receives the signal sent from the spare package 2 of the transmitting side device through the spare transmission path.

When the PN pattern signal received by the PN pattern check circuit 10 completely matches a preset PN pattern signal (normal time) or when both do not match, the counter section 11 described above is used. When the PN pattern signal returns to the normal state before the count value of 1 reaches the preset value N, the PN pattern check circuit 10 does not switch from the working to the protection.

Further, when the count value in the counter section 11 reaches a preset value N and the PN pattern check circuit 10 switches, a signal received from a spare transmission line also has an error pattern in the PN pattern signal. It is checked whether or not it exists, and when it does not exist, it switches to the backup transmission line, but when there is an error pattern, it does not switch from the working line to the backup line. A flow chart of the above-mentioned operation is shown in FIG.

As a result, the switching time can be shortened by the switching on the receiving side device independently, and since the command for switching control from the control unit need not be transmitted, the signal wiring can be reduced. .. Therefore, it can be one of the means for eliminating the complexity of the system.

[0021]

As described above, according to the present invention, it can be used for any redundant system having a duplicated transmission line, and it greatly contributes to the efficiency and performance improvement of the system.

[Brief description of drawings]

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

FIG. 2 is a block diagram showing a configuration of an apparatus according to an embodiment of the present invention,

FIG. 3 is a time chart for explaining the operation of the embodiment,

FIG. 4 is a flow chart for explaining the operation of the embodiment.

[Explanation of symbols]

100 is the first transmission unit, 120 is the pattern check / switching unit, 150 is the transmission device, 200 is the second transmission unit, 300 is the pattern generation unit, 500 is the pattern addition / error insertion unit, and 900.
Indicates a receiving device.

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

Claims (1)

[Claims] 1. A transmitter (150) having first and second transmitters (100, 200) for sending a main signal to each transmission line, and a transmission device (150) connected to each transmission line and through each transmission line. In a redundant system configured with a receiving device (900) that receives a main signal sent from the transmitting device, a pattern generating unit (300) that generates a signal of a predetermined pattern is provided in the transmitting device (150), A signal of a predetermined pattern output from the pattern generator (300) is added to the main signal and transmitted to the first and second transmitters (100, 200), respectively, or a failure occurs in a circuit in the preceding stage. In this case, a pattern addition / error insertion unit (500) for replacing a predetermined portion of the signal of the predetermined pattern to be added to the main signal with an error pattern and transmitting it is provided, and the receiving device (900) is provided with one of the transmission lines. The error pattern is detected for the signal received from one transmission line. Then, a switching system in a redundant system characterized in that a pattern check / switching unit (120) is provided for switching to receive a signal from the other transmission line when the number of times the error pattern is detected exceeds a predetermined value. .