JPH063931B2 - Fault handling method of loop bus control system - Google Patents

Description

TECHNICAL FIELD The present invention relates to a failure processing method for a network system using a loop bus control method.

(Prior Art) FIG. 1 shows a general frame structure of a conventional loop bus control system.

In the figure, F is a flag field indicating the beginning of the frame,
MA _{1 to} MA _n are maintenance instruction fields corresponding to n slave stations respectively, MB _{1 to} MB _n are fault display fields corresponding to n slave stations respectively, and C is a control signal between the master station and slave stations. A control field for communication, D indicates a data field for communication information.

Next, a case where a failure occurs in the second slave station in the frame structure shown in FIG. 1 will be described.

When a failure occurs in the second slave station on the loop bus in FIG. 1, the failure content is displayed in the failure display field MB ₂ corresponding to the second, and the master station corresponds to the second slave station. By looking at the fault display field, it is possible to know that a fault has occurred in the second slave station. Therefore, the master station sends a processing order using the maintenance instruction field MA ₂ corresponding to the second slave station. The slave station performs a return operation according to the instruction from the master station. Therefore, in this configuration, n kinds of failure display fields and maintenance instruction fields corresponding to the number of slave stations must be set in one frame on the loop, and the slave station side also has a timing of inserting the failure display into the failure display field and The timing for extracting the maintenance order from the maintenance instruction field is also different, so that the hardware configuration of each slave station is different.

(Object of the invention) In order to solve these drawbacks, the object of the present invention is to share one fault indication field and one maintenance instruction field with all the slave stations existing in the loop.

(Structure of the invention) A loop bus control system for connecting a master station for controlling the entire system and a plurality of slave stations in a loop, wherein data transmission from the master station to the slave station is performed in frame units, and A maintenance instruction field and a failure display field that can be transmitted / received independently from other fields are provided in the field of the frame, and the maintenance instruction field sends a maintenance order from the master station to the slave station in which a failure occurs in the slave station. In the fault processing method of the loop bus control system, wherein the fault indication field is configured to send fault occurrence information from the faulty slave station to the master station. By setting each station as a slave station having its own distinctiveness and displaying the information having the uniqueness of the slave station in the maintenance instruction field and the failure display field, The maintenance indication field and fault indication field, in which is characterized in that is shared by all slave stations present in the loop.

(Embodiment) In order to achieve the above-mentioned object, the embodiment of the present invention displays a fault indication field in a maintenance instruction field and information identifying a slave station, such as an address, and displays each field in all slave stations in the loop. It was solved by sharing. 2 and 3 are configuration diagrams showing an embodiment of the present invention, and the same components as those in FIG. 1 are designated by the same reference numerals.

That is, in FIG. 2, F is a flag field indicating the beginning of a frame, MA is a maintenance instruction field common to all slave stations, MB is a failure display field common to all slave stations, and C is a control signal between the master station and slave stations. , And D are data fields for communication information. Fig. 3 shows maintenance instruction field MA and failure display field.
It is a figure explaining the concrete structure of MB, ie, the field for maintenance, No is the address of the slave station assigned to each slave station, AL _m is the m-th failure display in the display contents of multiple types, and RS
T _m indicates that it is the m-th maintenance instruction order display suitable for the failure of AL _m among the contents of a plurality of types of maintenance instruction orders.

Next, this operation will be described with reference to the case of FIG. 4 (1). First, AL _{0 is} assigned to the second slave station N ₂ of the slave stations N ₁ to N _n.
If a failure occurs, the failure display field MB, N
Insert the slave station address No. 2 in o and the fault type AL ₀ in AL _m .

The information of this MB reaches the master station M from the slave station N ₂ on the loop bus via the slave stations N _{3 to} N _n . The master station M learns from the contents of MB that the slave station 2 has a fault of AL ₀ , and inserts the slave station address 2 and the maintenance order RST ₀ in the MA field. This MA
The field reaches the _first slave station N ₁ , the second slave station N _{2 to the nth} slave station N _n on the loop. Here, each slave station N ₁ ~
N _n checks the slave station address assigned to itself and the address number of the slave station in the MA field, and fetches the maintenance order when they match, so in this case, the second slave station N ₂ takes this order. After receiving the instruction and entering the recovery operation inside the slave station, the failure indication in the MB field is not displayed after recovery.

Next, a case where two slave stations simultaneously fail will be described with reference to FIG. 4 (2). AL ₁ respectively first and third slave station, when a failure of the AL ₃ occurs, at first, the first slave station N _1, the address No fault display field MB, assigned to the first slave station N ₁ Insert the specified address No. 1 and the fault content AL ₁ into AL _m . This MB information reaches the _third slave station N ₃ via the _second slave station N ₂ , but the third slave station N ₃ also has the fault AL _{3 and} therefore the third slave station N 3 _{At 3} , the No and AL _m displays in the MB field are rewritten as No 3 and AL ₃ , respectively. In the master station M are transmitted to the master station M fault information MB which is rewritten by the slave station N ₃ is via the slave station N ₃ slave station N ₄ to N _n,
MB field of No, by reading the AL _m display, the third to the slave station N ₃ knows that the failure AL ₃ occurs, MA field of No, the address No3 and maintenance instruction slave station N ₃ to RST _m Insert the order RST ₃ . This MA field reaches the _third slave station N ₃ via the slave stations N ₁ and N ₂ . Third slave station N
_For slave stations other than ₃ , the maintenance order will not be accepted because the No. in the MA field and the address assigned to the slave station do not match, but in slave station N ₃ , maintenance from the master station due to the match of the address When the order is received and the recovery operation is started according to the instruction, the failure display of the MB field is stopped and the failure information from the slave station N ₁ is passed, and the failure information is the slave stations N _{4 to} N. It reaches the master station M via _n . By reading the address No. in the MB field, the master station M can know that the slave station N ₃ has recovered and that the slave station N _{1 has} also failed. Here, as in the previous time, the master station sets the MA field No. and AL _m to the slave station address No. 1 and maintenance order, respectively.
Insert RST ₁ . In the first slave station N ₁ , if the maintenance operation order from the master station is entered and the normal operation is restored, the failure display of the MB field will not be displayed, and the failure display of the slave station on the loop will be completely eliminated. The fault display of is cleared.

According to the above-described embodiment, the field for maintenance is not set for the slave station and is shared by all the slave stations in the same loop, so that the field in the frame can be effectively used and each slave station can be effectively used. There is an advantage that the insertion and extraction timings corresponding to the maintenance fields can be made with the same configuration.

In the embodiment, when a plurality of slave stations are simultaneously troubled, the maintenance is performed from the last-stage slave station among those slave stations whose fault display field has been rewritten last. On the contrary, in order to perform maintenance from the slave station at the front stage, if the slave station at the front stage uses the fault display field, it is set so that the slave stations after the slave station cannot write in the fault display field. It is possible to maintain.

(Effect of the invention) According to the present invention, since the maintenance field is not set for each slave station and is shared by all slave stations in the same loop, the fields in the frame can be effectively used and each slave station can be effectively used. The insertion and extraction timing for the maintenance field of can be made with the same configuration.

Further, since the present invention is a loop bus control type fault handling system, it can be used for fault handling of a system in which various stations are installed in an optical loop type network.

[Brief description of drawings]

FIG. 1 is a conventional frame configuration diagram, FIG. 2 is a frame configuration diagram of an embodiment of the present invention, FIG. 3 is a diagram for explaining a specific configuration of a maintenance field, and FIG. 4 is an explanation of an embodiment of the present invention. It is a figure. F ... flag field, MA ₁ ~MA _n ... maintenance indication field, MB ₁ ~MB _n ... failure indication field, MA ... maintenance indication field, MB ... failure indication field, C ... control field, D ... data field, No ... child Station address, AL _m ... fault content display, RST _m ... maintenance order, M ... master station, N _{1 to} N _n ... 1 to n slave stations.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Shoichi Ogasawara 1-7-12 Toranomon, Minato-ku, Tokyo Oki Electric Industry Co., Ltd. (72) Inventor Masanari Hata 1-1-6, Uchisaiwaicho, Chiyoda-ku, Tokyo No. Japan Telegraph and Telephone Public Corporation (56) References JP-A-56-60142 (JP, A)

Claims (1)

[Claims] 1. A loop bus control system in which a master station for controlling the entire system and a plurality of slave stations are connected in a loop, wherein the plurality of slave stations are slave stations each having distinctiveness, the master station and each of the slave stations. Data transmission between slave stations is performed in frame units, and one maintenance instruction field and one failure display field that can be transmitted and received independently of other fields are provided in the field of the frame, and the maintenance instruction field is the parent A station sends a maintenance order to a specific slave station in the slave station, and the failure display field voluntarily sends failure occurrence information to the master station from the slave station in which the failure has occurred, without the instruction of the master station. However, the maintenance field and the failure display field are routed by incorporating one piece of information having the identification of the slave station in each of the maintenance instruction field and the failure display field. Failure processing method of the loop bus control system, characterized by using in common by all slave stations existing within.