JPH0244846A - Slave station supervisory system - Google Patents

Abstract

PURPOSE:To prevent the occurrence of a line use rate due to unnecessary line connection by making no answer by means of the judgement of the side of a slave station when the slave station does not have information which is worth transmitting to a control station. CONSTITUTION:When the slave station does not answer and the control station expects connection, the control station makes a call at a time (a), and completes the transmission of dials at a time (b). The control station simultaneously starts a first time limit supervisory function and a second time limit supervisory function. The slave station starts a third time limit supervisory function when it receives a cally signal, but it does not answer since it does not have information which is worth transmitting even it receives the call signal. Since the control station expects connection with the slave station, it furthermore keeps a call state. Thus, it comes to a third time limit T3 in the slave station. Consequently, the slave station learns that the control station expects connection and it answers at a time (e) with leaving little time. Thus, the line user rate can be saved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a dependent station monitoring system, and more particularly to a dependent station monitoring system in which a dependent station is given the right to choose a response.

C. Prior Art] In the conventional dependent station monitoring system, when the dependent station receives a call signal for monitoring from the control station, it immediately sends out a response signal and exchanges information.

[Invention or problem to be solved]

In the conventional dependent station monitoring method described above, when a dependent station receives a paging signal, it immediately sends out a response signal, so the line must be connected even if the dependent station does not have information worth sending to either the dependent station or the control station. First, there is a problem in that line usage fees are incurred due to unnecessary line connections.

SUMMARY OF THE INVENTION An object of the present invention is to provide a dependent station monitoring system that allows the dependent station to make a non-response at its own discretion if the dependent station does not have information worth transmitting to the control station.

[Means to solve the problem]

The dependent station monitoring method of the present invention is a dependent station monitoring method in which a control station monitors a plurality of dependent stations using a telephone line. a first time limit monitoring function that monitors a first time limit set for monitoring the response time of the dependent station;
a second time period that is sufficiently longer than the first time period;
and a second time limit monitoring function activated simultaneously with the time limit monitoring function and provided for the purpose of specifying a maximum waiting time for receiving a response from the dependent station, and when the dependent station receives the paging signal, the dependent station The configuration includes a third time period monitoring function that monitors a third time period that is longer than the first time period and shorter than the second time period, which is activated at the same time.

〔Example〕

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

FIG. 1 is a block diagram of one embodiment of the present invention.

The control station 1 is connected to a dependent station 34 via the telephone switching network 2. In order to obtain information from the dependent stations 3 and 4, the control station 1 calls one of the dependent stations in the same way as a normal subscriber terminal. , sends the subscriber number given to the subordinate station 3, and the telephone switching network 2,
Thereby, the control station 1 and the dependent station 3 are connected, and a paging signal is sent to the dependent station 3. If the dependent station 3 has information worth transmitting to the control station 1, the dependent station 3
It responds and sends out information. If it does not have information worth transmitting, it will not respond, but subsequent operations will be under the control of the control station 1.

Next, details of the operation will be explained.

Fig. 2 is a sequence diagram when the dependent station responds, Fig. 3 is a sequence diagram when the dependent station does not respond, and Fig. 4 is a sequence diagram when the dependent station does not respond and the control station wishes to connect. be.

If the dependent station responds, it is assumed that the control station makes a call at time a and has already completed sending out the dial.

The control station activates the first time limit monitoring function and the second time limit monitoring function at the same time. When the dependent station receives the paging signal, it responds at time C after some time. Since the response is shorter than the first time limit T1, the control station recognizes it as a dependent station response, and thereafter performs information transfer operations.

If the dependent station does not respond, the control station makes a call at time a,
It is assumed that the transmission of the dial has already been completed at the specified time. The control station is
Since the time has passed, the first time limit monitoring function and the second time limit monitoring function are activated simultaneously. When the subordinate station receives the paging signal, it
Activate the time limit monitoring function. However, even if the dependent station receives the paging signal, it does not respond because it does not have information worth transmitting. Therefore, at the control station, the first time period T1
will come. As a result, the control station determines that the dependent station does not have information worth transmitting. If the control station does not particularly recognize the need for connection, it sends out a recovery signal at time d when the first time limit T1 has elapsed, and stops sending out the calling signal.

If the dependent station does not respond and the control station desires connection, it is assumed that the control station makes a call at time a and has already completed sending the dial. The control station activates the first time limit monitoring function and the second time limit monitoring function at the same time. When the dependent station receives the call signal, it activates the third time monitoring function.

However, even if the dependent station receives the paging signal, it does not respond because it does not have information worth transmitting. Therefore, the first time limit T1 will come at the control station. As a result, the control station determines that the dependent station does not have information worth transmitting. Then, since the control station desires to connect with the dependent station, it continues to make further calls. As a result, the third time limit T3 will come at the dependent station. This allows the dependent station to know that the control station desires connection. As a result, the dependent station responds at time e after some time. Thereafter, information is exchanged under control from the control station.

In this case, if the dependent station does not respond even if the control station continues to call, the second time limit T2 will come at the control station. At this point, the control station determines that an accident has occurred in the dependent station, issues an alarm to the outside, sends out a recovery signal, and stops sending out the calling signal.

As described above, since the response connection operation of the dependent station is performed only when it is really necessary, the configuration is very suitable as a dependent station monitoring system using a general telephone switching network.

〔Effect of the invention〕

As explained above, the present invention enables the dependent station to make a non-response at its own discretion if it does not have information worth transmitting to the dependent station or control station, thereby eliminating unnecessary lines. This has the effect of preventing line usage charges due to connection.

1... Control station, 2... Telephone switching network, 3, 4... Dependent stations, a, b, c, d,, e... Time, T]...
...First time period, '1゛2... Second time period, T3...
Third period.

Claims (1)

[Claims] In a dependent station monitoring method in which a control station monitors a plurality of dependent stations using a telephone line, the control station starts to monitor the response time of the dependent station at the same time as it starts sending out a paging signal to the dependent station. A first time limit monitoring function that monitors a set first time limit, and a second time limit that is sufficiently longer than the first time limit and is activated at the same time as the first time limit monitoring function and receives a response from the dependent station. and a second time limit monitoring function provided for the purpose of specifying a maximum waiting time, wherein the dependent station is activated upon receiving the paging signal and is longer than the first time limit and shorter than the second time limit. A dependent station monitoring system characterized by having a third time limit monitoring function for monitoring a third time limit.