JPH01136446A - Fault location detecting system in duplexed loop transmission system - Google Patents

Abstract

PURPOSE:To expand the transmission enable range by providing a transmission line to transmission controllers (NCPs) on diagonal lines and using 2nd and 3rd small loop checking signals in addition to a small loop checking signal. CONSTITUTION:When an oscillation source NCP 117 detects a fault on loop transmission, a small loop checking signal is given in a route of 117 119 120 118 117. When no small loop checking signal is returned as the NCPs 107, 111, the NCPs 101, 111 gives the 2nd small loop checking signal in a route of NCP 107 NCP 105 NCP 106 NCP 107, 111, NCP 109 NCP 110 NCP 111. Then the 3rd small loop checking signal is given in a route of NCP 107 NCP 106 NCP 108 NCP 107 and the small checking signal is returned to the NCP 107. Then the NCP 107 bypasses the data to NCP 107 NCP 106 (diagonal transmission line 403).

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention provides a double loop transmission system with a detour configuration, in which a loop transmission line, a transmission control device (hereinafter referred to as NCP), and a detour fail. The present invention relates to a fault location detection method for detecting a fault location, configuring a detour at the time of a fault, and reconfiguring a detour at the time of recovery from the fault.

[Conventional technology]

The failure point detection method and recovery control method for a conventional loop transmission system with a detour configuration are disclosed in, for example, Japanese Patent Laid-Open No. 56-4.
0344, but in this method, if one or more failures occur on both loops in the transmission system, the transmission line that is actually capable of transmitting will be switched to one of the small loops that includes it. Due to a malfunction, a detour was constructed and it was not utilized. Therefore, there is a problem in that the range in which data transmission is performed is narrower than the range in which data transmission is actually possible.

[Problem that the invention seeks to solve]

In the above-mentioned conventional technology, when a failure occurs at one or more locations on both loops of a double-loop transmission system, the NCP checks the small loop including the location where the failure occurred and constructs a detour, but the transmission path is unconditionally closed. There was a problem that no consideration was given to transmission between them, and even if one transmission was originally possible, transmission became impossible. Additionally, if a failure occurs in a detour, a detour will be configured before the failed detour even if there are no other failures on the small loop that includes the detour and data transmission is possible. There was a problem that data transmission became impossible.

The purpose of the present invention is to expand the data transmission range of the system to the original data transmission range even if one or more failure points occur on each loop, or even if a detour route fails. The object of the present invention is to provide a failure location detection method.

[Means for Solving the Problem] In order to achieve the above object, in the present invention, one diagonal transmission line is connected from the specific side INCP of two adjacent paired NCPs to the NCP on the other loop side and not a pair. A small loop check signal that circulates around adjacent paired NCPs for detection, a second small loop check signal that goes around adjacent NCPs from the failure detection NCP and paired NCPs of the adjacent NCPs, and a second small loop check signal that goes around the adjacent NCPs and the paired NCPs of the adjacent NCPs from the failure detection NCP. The feature is that the third small loop check signal is sent to confirm that there is no abnormality in the transmission line between the failure detection NCP and the adjacent NCP, the diagonal transmission line, or the transmission line between the opposite NCP and the adjacent NCP. .

[Effect]

The NCP that transmitted the data detects a failure on the loop transmission path based on whether the data is returned again. The NCP that detects a failure issues a small loop check request signal to the paired NCP and also sends a small loop check signal itself to begin failure diagnosis. The NCP that has issued the small loop check signal determines whether there is an abnormality in the small loop surrounding the adjacent NCP based on whether or not the small loop check signal is returned.

If there is an abnormality, a second small loop check is performed in the first stage.

When the second small loop check signal returns, the signal transmission NC
It is determined that there is no abnormality in the transmission path between P and the adjacent NCP, and the data is sent to the adjacent NCP.If the signal does not return, it is determined that there is an abnormality, and the third small loop check signal is sent.If the signal is returned, it is determined that there is an abnormality. It is determined that there is no abnormality in the diagonal transmission line.
Send data to the diagonal transmission line, if the signal does not return,
Construct a detour to the NCP. In the conventional method, a detour is configured, which enables transmission between adjacent NCPs that are not in use.Also, if there is an abnormality in the transmission path between adjacent NCPs, data transmission can be performed by using a diagonal transmission path. The range of possibilities is expanded.

〔Example〕

An embodiment of the present invention will be described below with reference to FIG. 1st
The figure shows the configuration of the entire system.This system consists of a loop transmission line 1, which transmits information in opposite directions during normal operation,
On the loop with 2 is NCPIOI, 102, 103,
104..., but there is a detour 301 between the paired NCPs,
302, 303° 304... and one diagonal NC of NCP
There are detours 401, 402... between P, and furthermore,
Processing bag S for multi-pair NCP! 201, 202, . . . are connected by bidirectional transmission paths 501, 502, 503, 504, .

FIG. 2 shows the format of the message to be transmitted. A fixed configuration with flag sequences F501 and F507, between which a function code field FC502, a source NCP address field 5A503, and a control field C504 represent data contents.
, a data field 505, a frame check sequence 606 for error control, and a control field.

Serial number N508. Detour code CD509, detour counter C
It consists of T510 and small loop check number CC511. The NCP (source NCP) that transmitted the transmission data assigns a serial number to the data and transmits the data, and assigns the same serial number to the same data when retransmitting. NCP to import data (
If the receiving NCP) receives data with the same serial number from the same source again, it will be rejected. The detour code and detour counter are provided to prevent the same data from endlessly circulating on the transmission path. When the NCP detects a failure in the transmission path, the small loop check number sends out a small loop check signal, a second small loop check signal, and a third small loop check signal, and is provided to distinguish these three check signals. ing. The data format except for the small loop check number is exactly the same as that of the conventional autonomous decentralized system, and the behavior of the detour code and detour counter is also exactly the same.

Figure 3 shows the basic configuration of the NCP. Transmission processing device 70
9 refers to the reception function code table 710 and the received data table 716 to determine whether or not transmission to the host processing device is necessary for the data taken into the reception registers 704 and 706 from the transmission paths 701 and 702 during normal operation. In addition to transmitting the necessary data to the host processing device via the interface 713, the transmission data from the host processing device is transferred from the transmission status register 715 to the transmission register 703゜7.
05 to the transmission path, and when the transmission path is abnormal, the transmission status register 715 sends the signal to the transmission register 703 or 705,
707 to the transmission path, and also has the function of configuring a detour with the NCP via the interface 713 using the transmission status register.

Next, the failure detection and detour configuration method of the present invention will be explained. Anomalies on the transmission path are first detected at the source NCP.
will do it. If the transmitted data does not return to the source NCP within a certain period of time, the source NCP assigns the same serial number and retransmits the data.

If the data does not return to the source NCP even after retransmitting data a certain number of times, the source NCP determines that there is an abnormality in one of the NCPs on the loop or in the transmission path. NCP judged to be abnormal
The abnormality diagnosis is started by starting to send a small loop check signal. FIG. 4 is a conceptual diagram of the abnormality diagnosis method. When the source NCP 117 detects an abnormality in the loop transmission, it sends a small loop check signal along the route 117 → 119 → 120 → 118 → 117. Transfer loop check signal and NCP
It sends its own small loop check signal to 121. NCP1
17 issues a small loop check signal, and at the same time also issues a small loop check request signal to NCP 118, which is a source NCP (source NCP), and NCP 118 issues a small loop check signal. When a small loop check signal issued by itself is returned, such as in NCPs 117 and 118, it is determined that there is no abnormality on the small loop through which the small loop check signal passed, and normal operation is continued.

If the small loop check signal does not return like in NCP107, 111, NCP107, 111 changes from 107 to 105.
→ 106 → 107, 111 → 109 → 110 → 111 route sends the second small loop check signal, NCP10
In the case of 7, since the second small loop check signal is not returned, it is determined that there is an abnormality on the transmission path. and then 107
→ When the third small loop check signal is sent on the route of 106 → 108 → 107, the small loop check signal is NCP107
come back to.

Here, the NCP 107 detours the data from 107 to 106 (diagonal transmission path 4o3).

In the case of NCPIII, since the second small loop check signal is returned, it is determined that there is no abnormality in the transmission path between 111 → 109 → 110 → 11.1, and NCP11
Data will be streamed towards 9th.

The above process will be explained in detail below using a flowchart.

FIG. 5 shows the process from the source NCP detecting an abnormality to failure diagnosis. NCP transmits data step (801)
Then, the originating gNCP starts a timer (711 in Fig. 3).
is used to measure a certain period of time T, and check whether data has returned during that time (steps 802 and 803).
). If the data is not returned, the data is retransmitted with the same serial number (step 804).The counter in the NCP (710 in Figure 3) is cleared at the time of the first data transmission, but the data is retransmitted. One is added each time. After retransmission, check whether the number of retransmissions has reached a certain value (N) (step 805); if it has not, return to step 802; if it has reached it, call! N.C.
P judges that there is an abnormality on the loop (Step 806)
.

A small loop check signal is issued (step 807).

It also sends a small loop check request signal to the source NCP (step 808), and starts fault diagnosis.

FIG. 6 is a flowchart showing a procedure for diagnosing a fault by issuing a small loop check signal and taking steps to deal with the detected fault. The NCP sends out a small loop check signal (step 850), and if it returns with the small loop check signal it issued within a certain period of time Tz, it is determined that there is no abnormality on the transmission path surrounded by the four NCPs, and the process is normal. Continue driving (steps 852 and 853).

If the check signal does not return after a certain period of time Tl, the transmission line surrounded by 4NCPs (for example,
11→109→110→112→111) is judged to be abnormal (step 855). Next, a transmission line surrounded by 3NCPs (for example, 111 → 109 → 110 → 11 in Fig. 4)
1) sends the second small loop check signal (step 85
6).

If the second small loop check signal returns within a certain period of time T2, it is determined that there is no abnormality on the transmission path surrounded by 3 NCPs, and the adjacent NCP (for example, 111 → 109 in Fig. 4)
The data is sent to (steps 858 and 859). If the second small loop check does not return within a certain period of time T2, it is determined that there is an abnormality on the transmission path surrounded by 3NCPs (step 861). Next, a third small loop check signal is sent to the transmission line surrounded by 3 NCPs (for example, 107→106→108→107 in FIG. 4) (step 862).

If the third small loop check signal returns within a certain period of time T8, it is determined that there is no abnormality on the transmission path surrounded by 3NCP, and data is sent to the diagonal transmission path (step 8
64, 865), If the third small loop check signal does not return within the fixed time T3, it is determined that there is an abnormality on the transmission line surrounded by 3NCPs.Step 867) →108), and a detour is constructed (step 868).

When the loop transmission line having the fault location shown in FIG. 4 is recovered using the above-described fault diagnosis and recovery method, the data flow becomes as shown in FIG. 7. The state shown in Figure 7 is
This is the flow of data immediately after the abnormality diagnosis started from the NCP 107 is completed.

In this way, even if one partial failure occurs, the entire system will not go down.

Next, we will discuss recovery detection at a failed location. The NCP that detects an abnormality on the small loop (for example, 107 in FIG. 7) periodically sends a small loop check signal to detect abnormality recovery. FIG. 8 shows the recovery detection procedure of the NCP that detected an abnormality on the small loop, and the procedure after recovery detection. First, a small loop check signal is sent to detect failure recovery, and if the small loop check signal does not return within a certain period of time Tl, the small loop check signal is sent periodically. If the small loop check signal returns within a certain time Tz, 4NC
It is determined that the abnormality in the transmission path surrounded by P has been recovered, and a small loop check signal is taken in, a normal transmission command is issued, and normal transmission is restored (107→105 in FIG. 7).

As described above, in the case of a transmission line failure on one side of a small loop, the ability to use a diagonal transmission line and a normal one-sided transmission line has the effect of expanding the transmittable range.

〔Effect of the invention〕

According to the present invention, when a failure occurs at one or more locations in each of both loops of a double-loop transmission system as shown in FIG. If only the small loop check signal around the NCP is used, if there is a fault on the small loop, a detour will be constructed just before it. I couldn't take advantage of it. On the other hand, a transmission line is provided to AANcp on the diagonal, and a second line is installed in addition to the small loop check address. By using the third small loop check signal, a diagonal transmission line and a normal one-sided transmission line can be used, which has the effect of expanding the transmittable range.

[Brief explanation of the drawing]

The figures are all related to the present invention; Fig. 1 is a diagram of the overall system configuration, Fig. 2 is a diagram showing the format of transmitted messages, Fig. 3 is a basic configuration diagram of NCP, and Fig. 4 is abnormality diagnosis. Diagram showing the method. Fig. 5 is a flowchart showing the procedure from the source NCP detecting an abnormality to fault diagnosis, Fig. 6 is a diagram showing the fault diagnosis and detour configuration procedure, and Part 7 is an example of fault recovery using the above procedure. FIG. 8 is a flowchart showing the recovery detection procedure of the NCP that has detected an abnormality on a small loop and the subsequent procedure, and FIG. 9 is a diagram explaining the present invention in detail. 1/2゛°° directional transmission line/101/102°-N
CP-口201.202・,j-;Xtoprocessing device, 30
L, 302706.708...Reception register, 709
...Transmission processing device, 710...Receiving function code table, 711...Timer, 712...Counter,
713, 714 Figure 3
-7] VS diagram Figure 3

Claims (1)

[Claims] 1. Two loop transmission paths that transmit data in opposite directions, a pair of transmission control devices installed on the loop transmission path, and a device between each pair of transmission control devices that transmits data in opposite directions. Each transmission control device sends a small loop check signal to detect a failure on the closed loop on a closed loop consisting of two detour paths for transmission and two pairs of transmission control devices adjacent to each other on the loop transmission path. In a double-loop transmission system with the function of transmitting data, a diagonal transmission path is provided between two adjacent pairs of transmission control devices, and in addition to the small loop check signal, identification between three transmission control devices separated by the diagonal transmission path is performed. A double loop system characterized by outputting a second small loop check signal on one side for failure detection and a third small loop check signal on the other side to check whether transmission is possible to an adjacent transmission control device or a diagonal transmission control device. A method for detecting failure points in loop transmission systems.