JPH0125461B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to duplication of a master station system of a telemeter/telecontrol system.

(Background Art) Conventionally, in a telemeter/telecontrol system using a polling method, a duplex master station system functions simultaneously and independently for data processing, but a switching method is used for polling operations. Therefore, if the polling operation of one system's master station cannot be performed, the system switches to the other system's master station, but during that time, there have been cases of missing data.

(Problems to be solved by the invention) In order to solve these drawbacks, the present invention has two problems.
Two master stations independently poll at the same time,
This allows data to be collected without interruption even if one parent station goes down.

(Structure and operation of the invention) The present invention will be explained based on FIG. 2. In two master stations, polling is performed simultaneously by the clock of the branching device.
The station with the lowest number is the one that responds.
The branching device checks whether the station number matches the polled station number, and if it matches, the data is taken in, and if there is a mismatch or there is no response, the data is retransmitted a total of three times. As shown in FIG. 2, even in the case of a transmission error or station mismatch, all station data can be collected without missing data. When the 1st and 2nd systems poll the station (n+1), if only the 1st system is unable to collect data, the 1st system polls the station (n+1) again. In the second system, since the data of station (n+1) was successfully collected, polling of station (n+2) is performed. In the branching device,
Polling is performed on station (n+1) in order to poll with priority given to the small station number. In the 1st system, data of station (n+1) can be collected normally, but in the 2nd system, the data of station (n+2) can be collected normally.
Since the response of 1) is returned, polling is performed again to the station (n+2). Since the data of station (n+1) was successfully collected in the first system, the data of station (n+2) was collected next.
The polling of the 1st and 2nd systems can be synchronized. In addition, if only one master station performs polling, a certain period of time (waiting time (approximately 100 ms) that takes into account the difference in polling code transmission time of the control device of each master station)
The branching device waits to see if the master station of the other system is polled, and if the master station of the other system does not poll, polling is performed based on the station number of the one master station, and a response from the slave station is performed. (collected data) is
Output only to the master station that polled. Note that the polling period is about 6 seconds to 30 seconds.

(Effects of the Invention) As explained above, since the master station performs polling simultaneously and independently, the collected data is input to the master station systems of both systems, so that each system does not affect the other systems. Even if one controller goes down, the other system continues to collect data, which has the advantage of increased reliability. By connecting the branching device and both master stations using a serial interface, data can be collected without having to install the two master stations at the same location. Also, when polling is performed from the station with the largest station number, if the polling stations do not match, the large station
The same effect will occur if priority is given to No. polling. Since the master station systems are independent and do not affect each other, the present invention can be used when expanding and duplicating the system.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an apparatus for implementing the method of the present invention, and FIG. 2 is an explanatory diagram of the operation of the apparatus shown in FIG.

Claims (1)

[Claims] 1. In a system in which a duplicated master station collects data from a plurality of slave stations by polling, a branching device is inserted between the master station and the slave stations, and the two master stations poll at the same time. When the branching device detects that the station numbers of the polling stations from both master stations match,
A duplex method for a master station system of a telemeter/telecontrol system, characterized in that if they match, polling is performed using the station number, and if they do not match, polling is performed using the previous station number in a predetermined order. 2. In a method in which a duplicated master station collects data from multiple slave stations by polling, a branching device is inserted between the master station and the slave stations, and the branching device
When one master station polls and the other master station does not poll, the other master station is polled for a predetermined period of time, and if the other master station is not polled within the predetermined time, polling is not performed. 1. A duplex system for a master station system of a telemeter/telecontrol system, characterized in that polling is performed based on the station number of a master station that has been polled, and response data from a slave station is provided only to the polled master station.