JP2867922B2 - 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 which is one of monitoring and controlling systems for communication devices, and more particularly, a master station corresponding to a monitoring and controlling device of a satellite earth station polls a slave station which is a local device. The polling method when performing

[0002]

2. Description of the Related Art Conventionally, this type of polling method makes the acquisition of monitoring information of a slave station more efficient by changing the polling method for the slave station and the number of retries in polling between the master station and the slave station. It is used for the purpose of shortening the time. For example, in Japanese Patent Application Laid-Open No. 3-24838, a data collection start command is issued to all slave stations in advance,
The slave station prepares data in advance by the start command,
Without editing the response information at the next polling,
It describes a method for shortening the time by returning it to the master station. Japanese Patent Application Laid-Open No. Hei 3-13755 discloses a method in which polling is performed on a slave station having a state change to obtain information on the state change. Japanese Patent Application Laid-Open No. 1-228238 discloses that when a control command is issued to a certain slave station, a response to the command is immediately returned to the master station without waiting for the next polling from the master station. A method aimed at shortening the time is described.

[0003]

However, these conventional polling methods have a main purpose of shortening the time when notifying the status change of the slave station to the master station, and there has been a status change in a plurality of slave stations. In such a case, since the priorities are not assigned to the plurality of slave stations, the time required to acquire the slave station information may not be reduced. Also, in the invention of JP-A-3-13755, in the method of obtaining status change information preferentially to a slave station having a status change, if all the slave stations have a status change, the status is equally applied to all the slave stations. It's no different from polling for. In the method disclosed in Japanese Patent Application Laid-Open No. 1-228238, only a response (state change) to control is immediately notified to the master station. To reduce time or change priorities. In addition, since a failure on the transmission path between the master station and a certain slave station has not been determined, if there is a failure on the transmission path, the slave station must be retried in order to perform normal polling. Rather, it takes time for the number of retries to notify the master station of a status change of another slave station.

[0004]

In order to solve the above-mentioned problems, a polling method according to the present invention employs a polling method for transmitting monitored control information between a master station device and a plurality of slave station devices. in the polling method between a device and a plurality of slave stations performs transmission of the supervisory control information, the master station apparatus, for each slave station, polling top
A polling reference value that determines a large number of times, a priority number that determines the priority of polling of the slave station, and a retry counter that counts the number of retries when retrying polling performed on the slave station Is set in advance,
Means to store in memory and no response from the slave station
For example, the retry counter is incremented by 1 and if there is a response,
Subtracts 1 from the retry counter and
A retry counter calculation means for calculating the value of the pointer, and polling counter calculating means for calculating the value of the polling counter by subtracting the sum of the retry count and the priority numbers from a reference value of the polling, the retry count
Data calculation means and the polling counter calculation means are repeated.
And the polling counter value is not 0
Detects the largest slave station and polls the slave station .
Polling procedure changing means.

[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 a monitoring and control system according to the present invention.
-1 to 2-n are connected to the multipoint via the transmission line 3, and the master station 1 polls the slave stations 2-1 to 2-n in a calling system.

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

First, the block diagram of FIG. 2 will be described. In the polling processing section 9 of the master station 1, a polling reference value 5 previously determined in the memory 10 by the operator.
And the priority number 6.

[0009] Here, the polling reference value is a numerical value indicating the maximum number of times of polling for each slave station. This number is a value determined according to the number of slave stations and the polling time, and is set to a fixed value in advance.

[0010] The polling priority is a value selected according to the content of the monitoring control item of the slave station. That is,
If the content of the monitoring control item is important or changes in a short period of time, it is necessary to monitor and control more strictly, so that the priority is high. On the other hand, if the content of the monitoring control item is not very important or does not change in a short time, the priority is low.

Since this value changes according to the content of the monitoring control of each station, it is predetermined to a certain value for each station. However, the probability that a response is obtained by issuing a transmission request signal from the master station to the slave station, that is, , Depending on the response collection rate. That is, the polling priority is set to be higher for a slave station having a higher response collection rate, and the polling priority is set to be lower for a slave station having a lower response collection rate.

Although the configuration of the slave station is not described in detail, it has a function of receiving a polling signal from the master station and responding.

The calculation method of the slave station polling counter 8 is as follows.
The polling process is started by setting the polling reference value 5 to m and the priority number 6 of the specific slave station 2 to a, and waits for a response from the slave station 2. If there is no response, the retry counter 7 is incremented by 1, and the slave station polls. The counter 8 is decremented by the increment of the retry counter 7 (ma-1). This process is repeated until the slave station polling counter 8 becomes zero.

Next, the flow of the polling process of FIG. 3 will be described.

First, a polling reference value 5 which is the maximum number at that time is set in the slave station polling counter 8 (S
2) Also, the retry counter 7 is set to 0 (S
3).

The polling process is started (S4), the address of the slave station 2 having the maximum slave station polling counter 8 is searched, and the slave station 2 is polled (S6).

When there is no response from the slave station 2 (S7)
Increments the retry counter 7 by 1 (S12) and compares it with 3 which is the maximum value of the retry counter 7 (S13). If the retry counter 7 does not exceed the maximum value 3, polling of the slave station 2 is performed again.

If there is a response from the slave station 2, 1 is subtracted from the slave station polling counter number (S15).

When the retry counter 7 exceeds the maximum value 3 and when there is a normal response from the slave station 2, the retry counter 7 is counted from the slave station polling counter 8 of the slave station 2 to be polled. Is subtracted (S8). Next, the priority number 6 is subtracted from the slave station polling counter 8 of the slave station 2 to be polled (S9).

When the slave station polling counter 8 becomes smaller than zero, the slave station polling counter 8 is reset to zero. If the slave station polling counter 8 is larger than 0, the above polling process is performed until the slave station polling counters 8 of all the slave stations 2 become 0 (S10).

The slave station polling counter 8 of all slave stations 2 is set to 0.
When (S11), the polling reference value 5 which is the maximum value is set in the slave station polling counters 8 of all the slave stations 2 (S2). The above polling process is repeated.

FIG. 4 is a diagram showing a polling priority number table of the master station storing the above-described polling processing program. Address 1 to n for each slave station 2-1 to 2-n
, And ma-a-
x, mby,... mcz, mcx are set.

[0023]

As described above, according to the present invention, when a plurality of slave stations and a master station are connected at multipoint, the slave station polling counter subtracts the priority number of the slave station and the retry counter from the polling reference value. By deciding,
The polling procedure from the master station to the slave station can be changed,
Priority can be set for a plurality of slave stations.

Also, since the number of retries generated due to a fault on the transmission line is added to the calculation of the slave station polling counter, the time delay caused by retries to a specific slave station can be reduced, and no retry occurs. The monitoring information can be acquired with priority over the normal slave station.

[Brief description of the drawings]

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

FIG. 2 is a block diagram of a master station according to the present invention.

FIG. 3 is a flowchart of a polling process of the present invention.

FIG. 4 is a diagram illustrating a relationship among a slave station polling counter, a priority number, a polling reference value, and a retry counter.

[Explanation of symbols]

 1 master station 2 slave station 3 transmission line 4 address 5 polling reference value 6 priority number 7 retry counter 8 slave station polling counter 9 polling processing unit

Claims (1)

(57) [Claims] In a polling method for transmitting monitored control information between a master station and a plurality of slave stations, the master station determines a maximum number of polling times for each of the slave stations. A reference value, a priority number that determines the priority of polling of the slave station, and a retry counter that counts the number of retries when retrying the polling performed on the slave station are set in advance. And the retry counter if there is no response from the slave station.
Increment by 1
Subtracting 1 from the retry counter to calculate the value of the retry counter
And Ikaunta calculating means, and the polling counter calculating means for calculating the value of the polling counter by subtracting the sum of the priority numbers and the retry <br/> Lee counted from a reference value of the poll, the polling and the retry counter calculating means Coun
The polling counter value by repeating the data calculation means.
Detects the largest slave station that does not become 0 and responds to the slave station .
A polling procedure changing means for performing polling by means of a polling method.