JPS61196639A - Automatic recovering system for data communicating equipment - Google Patents

Abstract

PURPOSE:To automatize the loop recovery by expanding the loop and recovering to the system only when in the loop transmission system, the data communicating equipment, which generates the trouble and is separated from the loop, is confirmed to recover from the trouble by the self-diagnosis of the trouble data communicating equipment. CONSTITUTION:A data communicating equipment (d) having the monitoring function of the system as a whole transmits the recovery confirming indication of a data communicating equipment (a) which generates the trouble, to a data communicating equipment (b), for example, which loops back the transmission line. When a status latch 70 shows 1, a self-diagnosis function is started by an interruption generating part 80, the data communicating equipment (a) executes the self-diagnosis, the normality itself can be confirmed and then, the transmission line is looped back and the received carrier is folded back. A control latch 90 is set to 1, and after that, the interruption of the interruption generating part 80 is prohibited. The data communicating equipment (b) receives a carrier from the data communicating equipment (a) at a carrier receiving part 20, and when a status latch 71 is 1, the recovery confirming report is executed to a data communicating equipment (d).

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a loop transmission system in which a plurality of data communication devices are connected in series in a loop. , relates to a method for automatically rejoining the loop after repair.

[Background of the invention]

2. Description of the Related Art A loop transmission system is known in which a plurality of data communication devices are connected in series in a loop shape through a pair of transmission paths having opposite transmission directions.

FIG. 2 shows a schematic configuration of a loop transmission system, in which data communication devices ia, b, c, d are connected to a pair of transmission paths e,
f indicates that they are connected in a loop. Here, it is assumed that d is a data communication device having a system monitoring function. In the configuration shown in FIG. 2, a failure occurs in data communication device a.

If this occurs, devices b and c on both sides of the data communication device a
At this point, the transmission paths e and f are looped back, and the data communication device a is separated from the loop. FIG. 3 shows this state.

By the way, when data communication device a, which has been disconnected from the loop due to this failure, is to be rejoined to the loop after repair, conventionally, maintenance personnel have to respond to input of a loopback cancellation command using the device's keyboard, etc. Then, the data communication device d, which has a monitoring function for the entire system, issues a loop pack release instruction to the data communication devices d and c that are looping back, and the data communication devices b and c release the loopback. The system returns to the configuration shown in Figure 2,
Communication was enabled for data communication device a that had recovered from the failure. This is disclosed, for example, in Japanese Patent Application No. 58-29156. A drawback of this conventional method is that a data communication device that has recovered from a failure cannot be brought back into the loop without human intervention.

[Purpose of the invention]

An object of the present invention is to automatically restore a data communication device that has recovered from a failure to the loop in a loop transmission system, thereby enabling communication between the data communication devices.

[Summary of the invention]

An outline of the automatic recovery method of the present invention will be explained with reference to FIGS. 3 and 4. As shown in FIG. 3, it is assumed that a failure occurs in data communication device a, and transmission paths e and f are looped back in data communication devices b and c on both sides of the data communication device a.

First, a data communication device d having a system monitoring function,
For example, data communication [b
Sends a recovery confidence instruction for the data communication device [a] where the failure has occurred. In response to this, the data communication device A uses its carrier wave transmission/reception function to transmit the carrier wave to the data communication device a.

After receiving the carrier wave, data communication device a performs a self-diagnosis-3= to confirm normality, loops back the transmission path, and returns the carrier wave to the data communication device.

'When a carrier wave is received from data communication device a, data communication device A sends data communication device a to data communication device d.
Report disaster recovery. In response to this, data communication equipment d
sends a loop expansion instruction to the data communication device, and the data communication Wb cancels loopback. As a result, as shown in FIG. 4, the loop expands to the data communication device Wa, and the data communication device a and the other data communication device fi! Zb,
Communication with c and d becomes possible.

[Embodiments of the invention]

FIG. 1 shows a block diagram of an embodiment of a data communication device that implements the system of the present invention. In FIG. 1, reference numeral 1 denotes a data communication device, which has a control unit 2 that performs data transmission and reception control, carrier wave transmission and reception control, and the like. 10 and 20
1 is a carrier wave receiving section, and 11 and 21 are carrier wave transmitting sections connected to transmission paths e and f, respectively. 40 is a switch circuit for transmitting data received by the carrier wave receiving units 10 and 20 to the carrier wave transmitting unit 11 or 21. 60～
63 is a control latch group for controlling the switch circuit 40; if the control latch 60 is IE'H, the carrier wave receiving section 1
If the data received at 0 is transmitted to the carrier wave transmitter 11, and the control latch 61 is ``1'', the data received at the carrier wave receiver 10 is transmitted to the carrier wave transmitter 21, and the control latch 62 is set at tg 171. If there is, the data received by the carrier wave receiving unit 20 is sent to the carrier wave transmitting unit 21, and the control latch 63
If is 1'', the data received by the carrier wave receiving section 20 is transmitted to the carrier wave transmitting section 11.

70.71 is the status latch, status latch 7
When 0 is 11' 1 j#, it indicates that the carrier wave reception unit 10 is receiving a normal carrier wave, and when the status register 71 is II 111, it indicates that the carrier wave reception unit 20 is receiving a normal carrier wave. Show that there is. The contents of these status latches 70.71 can be read by the software of the control unit 2. 80 is an interrupt generation unit for the software, which generates an interrupt when either status latch 70 or 71 changes from '0'' to tE'r, and activates the self-diagnosis function of the software. 9o is a rough 1 ~Ware is a control latch for controlling the interrupt generating section 80, and when the latch 90 is 1'', it prohibits the interrupt generating section 8.degree. from generating an interrupt.

The operation shown in FIG. 1 will be explained below. Assume that the loop transmission system has the configuration shown in Fig. 2, in which data communication device a has failed, and data communication devices b and c adjacent to data communication device a are looping back transmission lines e and f. shall be. This state is shown in FIG. In this case, in data communication device ia, control latches 60 to 63 are all set to 1801g, and transmission paths e and f are cut off in data communication device a. The carrier wave receiving sections 10 and 20
, carrier wave transmitters 11 and 21 remain connected to transmission paths e and f, respectively. In the data communication device, the control latch 61 is set to rr I IT, and the other control latch 60°6.
2.63 is set to '0'', the carrier wave receiver 10 is connected to the carrier wave transmitter 21 via the switch circuit 40, and the transmission lines e and f are looped back.

Similarly, in data communication device C, control latch 60°61
．． 62 rr O,, control latch 63 II 11H
The carrier wave receiver 20 is connected to the carrier wave transmitter 11, and the transmission paths e and f are looped back.

Now, the data communication device d, which has a monitoring function for the entire system, periodically activates the system monitoring function to monitor whether there is a faulty data communication device in the system. This is, for example, data communication device a.

This is done by sequentially calling b and c and checking the responses. When data communication device a confirms that the loop has not been restored yet, data communication device d determines that a failure has occurred in, for example, a data communication device looping back the transmission path. A recovery confirmation instruction for data communication device a is transmitted.

Data Communication Nb, which has received the recovery confirmation instruction from the data communication device id, sets the control latch 60 to 1'', connects the carrier wave receiver 10 to the carrier wave transmitter 11, and connects the carrier wave receiver 10 to the carrier wave transmitter 11, and
The data communication device ta sends out a carrier wave to the data communication device a and monitors whether the status latch 71 indicates '1''. zr 1 u. When the status latch 70 indicates rr 1 u,
When the self-diagnosis function fails to start due to the interrupt generation unit 80,
(The control latch 90 is set to tt Orr), and the data communication Ma performs self-diagnosis. If the self-diagnosis confirms the normality of the data communication device a, if the status latch 70 indicates 111 II, the data communication device a sets the control latch 61 to '1'' and sets the status latch 71 to II I.
If it indicates B, the control latch 61 is set to Ll 1 gH, the transmission path is looped back, and the received carrier wave is turned back.

Then, the control latch 90 is set to 'l' to prohibit subsequent interrupts from the interrupt generator 80.

In this example, the data communication device a has the status latch 7
Since 0 indicates 11144, when the normality of the own device is confirmed, the control latch 61 is set to 1'1'', the carrier wave receiving section 10 is connected to the carrier wave transmitting section 21, and the transmission lines e and f are connected.
is looped back and the received carrier wave is returned to the data communication device. Note that if an abnormality is discovered again through self-diagnosis, the data communication device a will close the control latches 60, 61, 62.
．． Leave 63 and 90 as before and do nothing.

The data communication device A receives the carrier wave from the data communication device a in the carrier wave receiving section 20, and the status latch 71 is
1", a recovery confirmation report is sent to the data communication Ht3. Also, if the carrier wave does not arrive from the data communication device a and the status latch 71 does not indicate "1" within a certain period of time, the data communication device Send unrecovery report to data communication device d
At the same time, the control latch 60 is returned to 180 II to stop the carrier wave to the data communication device a.

When the data communication device d receives a non-recovery report from the data communication device, it immediately ends the automatic recovery operation for the faulty data communication device a.

When receiving a recovery confirmation report from the data communication device d, the data communication device d transmits a loop expansion instruction to the data communication device b. The data communication device that has received the loop expansion instruction sets the control latch 61 to 0'' and sets the control latch 62 to 0''.
If the control latch 60 is set to II I H, the control latch 60 is already set to 11.
1 #I, the control latch 63 is set to '0''), the loopback is released. This state is shown in FIG. Data communication equipment.

It becomes possible to send and receive data to and from c and d. Thereafter, a data transmission/reception test is performed between the data communication device fld and the data communication device a, and if it is successfully completed, the automatic recovery of the faulty data communication device a is deemed to have been successful and the operation is terminated. If the data transmission/reception test fails, Data Communication Wd transmits a loopback instruction to data communication device b, and terminates the operation as a recovery failure. The data communication device that received the loopback instruction from the data communication device ID is the control latch 61
is set to zr 1 n, the other control latches 60, 62, 63 are set to re Oto, the transmission lines e and f are looped back, and the data communication device a is disconnected from the loop again.

FIG. 5 is a flowchart summarizing the operations of data communication device d having a system monitoring function, and FIG. 6 is a flowchart summarizing the operations of data communication devices a, b, and c. Of these, FIG. 6(a) shows a flowchart at the time of interrupt activation of data communication device a where a failure has occurred, and FIG. 3 shows a flowchart of a communication device S or C.

〔Effect of the invention〕

According to the present invention, in a loop transmission system, a data communication device that has experienced a fault and has been disconnected from the loop can be recovered from the fault by self-diagnosis of the faulty data communication device without receiving instructions from outside the system. Only when this is confirmed, the loop can be expanded and restored to the system, which has the effect of automatically restoring a data communication device that has been disconnected from the loop to the loop without any manual intervention.

[Brief explanation of drawings]

Fig. 1 is a block diagram of an embodiment of a data communication device that implements the method of the present invention, Fig. 2 is a schematic diagram of a loop transmission system, Fig. 3 is a diagram showing a loopback configuration in the event of a failure, and Fig. 4 1 is a diagram showing a configuration for canceling loopback, and FIGS. 5 and 6 are processing flow diagrams for explaining the operation of FIG. 1. a, b, e...data communication device, d...data communication device with system monitoring function, e, f...transmission line,
1... Data communication device, 2... Control unit, 1
0.20...Carrier wave receiving section, 11.21...Carrier wave transmitting section, 40...Switch circuit, 60.63.
...Control latch, 70.71...Status latch, 80...Interrupt generation section, 90...Control latch. Figure 5 Periodic Figure 6 (θ) (b)

Claims (1)

[Claims] (1) In a loop transmission system in which a plurality of data communication devices are connected in series in a loop through a pair of transmission paths with opposite transmission directions, at least one data communication device has a system monitoring function, and the other data communication devices have a system monitoring function. The data communication device has a self-diagnosis means for checking the normality of the own device, and a means for looping back/releasing the transmission path. A data communication device that has a system monitoring function when a device A is disconnected from the loop by looping back the transmission path with the data communication devices on both sides of the device a (hereinafter referred to as devices b and c). (hereinafter referred to as device d), device b or c (hereinafter referred to as device b) sends a carrier wave to device a, and device a, which receives the carrier wave, diagnoses the normality of its own device. If normality is confirmed, the transmission path is looped back and the received carrier wave is returned to device b. When device b receives the carrier wave, it reports the failure recovery to device d, and in response, the loop from device d is An automatic recovery method for a data communication device, characterized in that upon receiving an enlargement instruction, loopback is canceled and device a is restored to the loop.