JPH01106654A - Fault information collection system - Google Patents

Abstract

PURPOSE:To reduce the information collection time and the line occupancy rate of a polling by circulating a fault location detecting frame so as to set a fault location and applying polling to the faulty location only in detecting a fault by a control frame circulated at all times. CONSTITUTION:A centralized control station CS circulates a control frame CD in the direction of arrow on transmission lines L0, L1 at all times to manage the transmission lines L0, L1 and terminal stations N1-N3. If a fault takes place in a terminal station, the terminal station (e.g., N2, N3) sets a fault recognition bit FB. In recognizing it, the control station CS circulates two fault location detection frames FD in both directions by once. Since the terminal station N1 is normal, the relevant bit n1 of its own station is set, but the terminal stations N2, N3 cause a fault, the relevant bits n2, n3 are not set. The control station CS detects the fault occurrence terminal stations N2, N3 from the content of the returned frame FD and then applies polling to the terminal stations N2,N3 to collect fault detail information.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a failure information collection system, particularly to a failure information collection system in a ring network in which a central control station constantly circulates control data.

[Conventional technology]

In the conventional fault information collection method of this kind, first, a terminal station where a fault has occurred receives fault recognition information in a control frame CD as shown in FIG. 4 from a central control station.

) FB was set to "1", and upon receiving this, the central control station sequentially polled all end stations, and based on the results, collected the location and cause of the failure.

[Problem that the invention seeks to solve]

The above-described conventional method polls all end stations even when there are only a few failure points, so it has the disadvantage that the line occupancy rate due to polling is high and it takes time to collect information on all failure points.

[Means for solving problems]

The method of the present invention is a fault information collection method in a dual-structured ring network controlled by a central control station. When the central control station recognizes the occurrence of a fault by setting the fault recognition bit at the terminal station where the fault has occurred, it circulates the fault location detection frame with bits corresponding to each terminal station for one cycle to detect the fault. This feature is characterized in that the terminal station that is not present sets the corresponding bit, and the central control station can identify the location of the failure, thereby collecting failure information from the terminal station using a polling method.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIGS. 1, 2, and 3 show an embodiment of the present invention, in which FIG. 1 shows a state where no fault has occurred, and FIGS. 2 and 3 show a state after the fault has been recognized. Also, Figure 4 shows the transmission line L.
o, control frame CD constantly circulating on Ll, fifth
The figure shows details of the failure point detection frame FD.

This embodiment is a duplex ring network in which a central control station C8 and three terminal stations N1+N2 and N3 are connected by two transmission lines Lo and Ll.

As shown in FIG. 2, the centralized control station C8 constantly circulates the control frame CD counterclockwise on the transmission line Lo, and clockwise on the transmission line Lo, so that the control frame CD Terminal N1. It manages N2 and N3. That is, in a state where no fault has occurred, the fault recognition bits FB in the two control frames CD are monitored.

When a failure occurs at a terminal station, the terminal station where the failure occurred (N
2 and N3) sets the fault recognition bit FB. When the central control station C8 recognizes a fault, it circulates the two fault detection frames FD in both directions as shown in FIG. In addition, as mentioned above, the control frame CD
As is well known, the effect of the duplex structure in which the fault detection frames FD circulate in both directions is to reduce the probability that these frames will not be transmitted to terminal stations beyond the fault location due to a fault in the transmission path.

Since the terminal station N is normal, the corresponding bit n of the own station
However, the terminal stations N2 and N3 do not set the relevant bits n2+n3 because a failure has occurred in their own stations.

The central control station C8 detects the terminal stations n2 and N3 where the fault has occurred based on the contents of the returned fault detection frame FD. After that, as shown in Fig. 3, polling is performed on the terminal stations N2+N3 where the failure has occurred, and
Collect detailed information about the failure.

〔Effect of the invention〕

As explained above, in the present invention, when a fault is detected using a constantly circulating control frame, the fault location detection frame is circulated to set the fault location, and polling is performed only for that fault location. This eliminates polling, reduces the polling line occupancy rate, and reduces the time required to detect all failure points and collect information.

[Brief explanation of the drawing]

1, 2 and 3 are one embodiment of the present invention, and FIG.
The figure shows a general control frame, and FIG. 5 shows a failure point detection frame used in the present invention. C8...central control station, N,, N2. N3...Terminal station,
Lo, Ll...transmission line, CD...control frame, F
D: Fault detection frame, FB: Fault recognition pit, SD: Frame identifier.

Claims (1)

[Claims] In a fault information collection method in a dual-structure ring network controlled by a central control station, the central control station constantly circulates a control frame having a fault recognition bit that can be set commonly by all terminal stations, and detects faults. When the central control station recognizes the occurrence of a fault by setting the fault recognition bit in the terminal station where the fault occurred, it circulates the fault location detection frame with bits corresponding to each terminal station for one round and detects the fault. Fault information collection characterized in that a terminal station in which no occurrence of a fault has occurred sets a corresponding bit, and the central control station can identify the location of the fault, and collect fault information from that terminal station by a polling method. method.