JP2570159B2 - Polling method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polling system, and more particularly to a polling system in which a master station performs a plurality of slave stations in monitoring and controlling a satellite earth station having a working or standby configuration.

[0002]

2. Description of the Related Art Conventionally, in this type of polling method, various polling methods have been proposed for the purpose of increasing the efficiency of acquisition of monitoring information of a slave station in a master station and a plurality of slave stations and shortening the time until information acquisition. Have been. For example, JP-A-3-29
No. 439 and Japanese Unexamined Patent Publication No. 60-58741 disclose the time required for supervisory control by performing polling with a minimum number of retries for a slave station that was abnormal at the previous polling. A method aiming at shortening is described. Japanese Patent Application Laid-Open No. 62-131639 discloses that, when a slave station is operating normally for a predetermined time, the slave station is excluded from the calling order, polls other slave stations, and the slave station is controlled by the master for a predetermined time. A method aimed at shortening the polling cycle time by transmitting the operation state of the own station to the master station only when a state change occurs in the slave station when the station is not called is described.

[0003]

However, Japanese Patent Laid-Open Publication No. Hei 3-2
In the conventional polling method in the inventions of Japanese Patent No. 9439 and Japanese Patent Application Laid-Open No. 60-58741, the minimum number of retries is performed for the slave station that detected the abnormality at the time of the previous polling. If there are multiple slave stations that have detected the error, it may take some time before polling is performed on other normal slave stations. There was a big problem depending on the number of stations. In addition, Japanese Unexamined Patent Publication
According to the polling method in the invention of Japanese Patent Application Laid-Open No. 2-131639, when a slave station operates normally for a predetermined time, the slave station is excluded from the calling order and polls other slave stations, and the slave station is called from the master station for a predetermined time. Otherwise, the operation mode of the own station is transmitted to the master station only when a state change occurs in the slave station. When a failure occurs in which the status cannot be transmitted to the master station, the master station has a problem that the abnormality of the slave station cannot be permanently detected. Further, when the slave station has to send an item whose state constantly changes, such as a measured value, to the master station, the polling cycle time is not much different from the case of polling all slave stations. Also,
When the slave station is in a normal state, since neither the master station nor the slave station performs communication, there is also a problem that it is not possible to detect an abnormality on a transmission line connecting the master station and the slave station. .

[0004]

In order to solve the above-mentioned problems, in the polling method of the present invention, polling is performed for all the slave stations, and only for the slave station to which a response has been transmitted normally. First poll,
The slave stations are classified based on the working spare information of the slave stations. The spare slave station polls one station at a time, polls all the working slave stations, and repeats polling by the number of spare slave stations. The first means, and in the first means, when polling the working slave station, further classify the slave station into a malfunctioning slave station and a normally operating slave station;
The abnormal working slave station polls one station at a time, performs polling for all working slave stations, and repeats polling for the number of abnormal working slave stations. If the current spare information is changed at the time of the operation, a third means is provided for returning to the first means and newly acquiring the current spare information for all the slave stations.

[0005]

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a diagram showing a multipoint configuration of the monitoring and control system.

In this figure, a plurality of slave stations 2-
Connect 1-2-n to the multipoint via the satellite 3,
The master station 1 polls a plurality of slave stations 2-1 to 2-n in a calling manner. Master station 1 and child stations 2-1 and 2-2
In the case of −n, the transmitting / receiving apparatus has a working spare configuration.
In the present surveillance control system, each slave station has a function of transmitting to the master station whether the working or the protection is in operation (working spare information) in response to a request from the master station. One. As another monitoring item, when there is no response from the slave station three or more times, it is determined that communication on the satellite line has not been established.

FIG. 2 is a diagram showing an outline of a processing flow of the polling method of the present invention.

FIGS. 3 and 4 show slave stations 2-1 to 2-n.
3 shows a specific flow of a polling process performed based on the working spare information or communication (link) information.

The polling process of the master station 1 and the slave stations 2-1 to 2-n will be described below with reference to FIGS.

First, the "polling process for all slave stations" (P1) will be described with reference to the flow of FIG.

[0012] In the flow of FIG.
Variable whose initial value is 1 to set the ring order
i, a, and b are provided (S1). The master station is the slave station No. i (i
= 1 to n) (S2), and
It is determined whether the communication (link) is normally established (S
3). If an error is detected,
Judge whether it is the maximum value of i (the number of all slave stations: n)
(S9) If it is not the maximum value, 1 is added to i (S9).
10), slave station No. Polling for i (S
2). For stations where an error is detected by this method,
After polling all slave stations for the first time,
Is not performed. Also, no abnormality was detected
In the case, the polled slave station No. i response
Depending on the content, the slave station No. The current spare information of i is acquired (S
4) If the station is currently in use, slave station No. i is the active slave station N
o. a (S5), 1 is added to a (S6),
It is determined whether or not i is the maximum value (the total number of slave stations) (S9).
If the value is not the value, i is set to 1 to poll the next slave station.
Is added (S10) and the slave station No. polling i
Perform (S2). If it is a spare, slave station No. Reserve i
Slave station No. b (S7), 1 is added to b, and then (S
8) judge whether i is the maximum value (the number of all slave stations) (S
9) If it is not the maximum value, poll the next slave station.
Therefore, 1 is added to i (S10) and the slave station No. i to po
Is performed (S2). When i reaches the maximum value,
When polling is finished for all slave stations,
The current values of variables a and b are represented by A MAX, B MAX
(S11).

Next, a description will be given of "polling processing for all active slave stations for one spare slave station" (P2) in FIG.

In FIG. 3, the value of the variable b is returned to the initial value 1 (S12), and the value of the variable a is also returned to the initial value 1 (S1).
3). Spare station No. b is polled (S1
4) If a response is returned normally and the current spare information remains unchanged and remains spare (S15, S1)
6), variable b is B Check that it is not MAX (S1
7) Enter the “polling process for the active slave station” (process 1). b is excluded and the variable b is B Check that it is not MAX (S1
7) Enter "Polling process for working slave station" (process 1). Spare station No. When b changes to working and variable b
Is B When it becomes MAX, that is, when polling is completed for all the spare slave stations, it is determined that the working spare information has been changed, and the process returns to START to perform the “polling process for all slave stations” (S2) and perform the current working. Start again from obtaining preliminary information. When the polling processing for the working slave station is completed, 1 is added to the variable b (S18), and the next spare slave station is polled (S14).

Next, "Polling process for working slave station"
(Process 1) will be described.

In FIG. 3, variables m and n having an initial value of 1 for setting the order of polling the working slave station.
Is provided (T1). Working slave station No. Then, polling is performed for a (T2), and it is first determined whether communication has been normally established (T3). If an abnormality is detected, the active slave station No. a is the abnormal slave station No. n (T7),
After adding 1 to the variable n (T8), the variable a becomes A MAX
(T9), and polls the next working slave station (T2). If no abnormality is detected and the working spare information is changed, the process exits from the repetitive processing (result 1). ), Return to START, perform from "Polling process for all slave stations" (S2), and start over from obtaining the working spare information. If no abnormality is detected and there is no change in the working spare information (T4), the working slave station No. a is the normal slave station No. m (T5),
After adding 1 to the variable m (T6), the variable a becomes A MAX
(T9), and polls the next active slave station (T2). Variable a is A When the value becomes MAX, that is, after the polling process is completed for all the active slave stations, the current values of the variables m and n are set to M, respectively. MAX,
N Save as MAX (T11).

Next, a description will be given of a process of polling all the abnormal child stations for one abnormal child station.

The value of the variable n is returned to the initial value 1 (T12),
Next, the value of the variable m is also returned to the initial value 1 (T13). Abnormal slave station No. n (T14), a response is returned normally (T14), and if the active spare information remains unchanged (T16), the variable n is set to N.
After confirming that it is not MAX (T17), the polling process for the normal slave station is started (T18). If it is abnormal (T15), the variable n is set to N. After confirming that it is not MAX (T17), polling processing for a normal slave station is started (T18). Abnormal slave station No. If n has changed to standby (result 1), the process returns to START to perform the polling process for all slave stations (S2), and starts again from the acquisition of the working standby information, and the variable n becomes N. When MAX is reached (P
4) In other words, when polling has been completed for all abnormal slave stations (result 2), 1 is added to the variable b, and polling processing is performed for all spare slave stations (S14). Similarly, the normal slave station No. polling m (T18),
If a normal response is returned (T19) and the active spare information is not changed (T20) and remains active,
Variable m is M Confirm that it is not MAX (T21)
One is added to the variable m (T22), and polling is performed for the next normal slave station (T18). An abnormality was detected (T1
9) If variable m is N Confirm that it is not MAX (T
21), 1 is added to the variable m (T22), and polling is performed for the next normal slave station (T18). Normal slave station No. m
Is changed to the spare (result 1), the process returns to START, and the polling process (S2) is performed for all the slave stations, and the process starts again from the acquisition of the working spare information. Returning to "Polling process for all slave stations" (P1), when there is a change in the working spare information (P5, P6), the polling process has been completed for all the working slave stations for one spare slave station. It is time (P7).

[0019]

As described above, according to the present invention, when a plurality of slave stations and a master station are connected at a multipoint, only the slave station with which communication was established at the time of the first polling is monitored and the slave station is monitored. By changing the polling procedure from the master station according to the working spare information of the station, the normal slave station to be monitored can be minimized and appropriately selected, so that the polling cycle time can be reduced. The polling order is set for each of the working slave station and the spare slave station based on the working spare information of the slave station with which communication has been established.
Polling is performed for each station, the working slave station polls all stations, and polls the working slave stations by the number of spare slave stations.
After polling all spare slave stations, the master station must again poll the slave stations from the beginning. Can be.

When polling an active slave station, a slave station with which communication has been established based on link information for each slave station is defined as a normal slave station, and a slave station with which communication has not been established is determined as an abnormal slave station. The abnormal slave station polls one station at a time, the normal slave station performs polling for all the slave stations, polls the number of abnormal slave stations, polls all the abnormal slave stations, and then returns to the slave station from the master station again. Since the station is polled from the beginning, it is possible to respond flexibly even if an error is detected in the slave station during the polling process, and when the working slave station returns to normal, the information is given priority over the spare slave station. Can notify the master station.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a multipoint configuration to which a conventional device and an embodiment of the present invention are applied.

FIG. 2 is a flowchart showing an outline of a polling process performed by a master station and a slave station.

FIG. 3 is a flowchart of a polling process performed based on the working spare information of the slave station.

FIG. 4 is a flowchart of a polling process performed based on link information of a slave station.

[Explanation of symbols]

 1 master station 2 n station slave stations 3 satellite

Claims (3)

(57) [Claims] 1. In a polling system in which a master station and a plurality of slave stations in a working standby configuration communicate with each other via a satellite to monitor and control the slave stations, communication is established when all slave stations are polled. A polling system comprising: a first unit to be monitored only; and a second unit for changing a polling procedure based on active spare information of a slave station with which the communication has been established. 2. The second means according to claim 1, wherein the order of polling is set for each of the working slave station and the spare slave station, the spare slave station performs polling one station at a time, and the working slave station performs polling processing for all stations. After repeating the polling process for the working slave stations by the number of spare slave stations, and completing all slave stations,
A polling method characterized by performing the first means again. 3. The polling of the working slave station according to claim 2, wherein a slave station with which communication is established is regarded as a normal slave station, a slave station with which communication is not established is regarded as an abnormal slave station, and the abnormal slave station performs polling one by one. A polling method in which a normal slave station performs polling processing for all stations, repeats polling processing for the number of abnormal slave stations, and performs the first means again after completing all slave stations.