JPH0548650B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Technical Field of the Invention The present invention relates to a plurality of slave stations in a telemeter system connected by a multi-drop line that branches signals from a master station to a plurality of slave stations on the same line. The present invention relates to a telemeter terminal device installed in.

(b) Background of the technology Telemeter systems used for pollution monitoring, power transmission system monitoring, road condition monitoring, etc. are measurements obtained by measuring instruments installed at numerous measurement locations (child stations). This is a system used to continuously monitor data at a single center (master station) at regular intervals.In such a telemeter system, as shown in Figure 1, there is a main station 1 and multiple (n slave stations 21, 22...
For example, the slave station 2n is connected to
In many cases, the measurement data is transmitted to the master station 1 by taking turns in the following order: 1, slave station 22... slave station 2n.

(c) Prior art and problems In the telemeter system connected by the multi-drop line, the slave station 21, the slave station 2
2... In order to transmit measurement data to the master station 1 by taking turns in the order of slave stations 2n, conventionally, the master station first polls (inquires) each slave station 21, 22...2n. The method used was to visit the company and ask them to send measurement data.

FIG. 2 is a block diagram showing an example of the configuration of a telemeter terminal device provided in each slave station 21, 22...2n of such a telemeter system.
4 is a demodulation unit that demodulates the inquiry signal A, which is a carrier wave signal modulated by a modulation signal and transmitted from the master station 1, and 4 is a serial-parallel conversion unit that converts the serial signal demodulated by the demodulation unit 3 into a parallel signal. Department (S/P
5 is a determination unit that determines whether the inquiry signal A transmitted from the master station 1 is for the slave station, and 6 is a measurement data B to be transmitted to the master station.
A parallel-serial converter (P/S converter) converts the parallel signal into a serial signal, and 7 is a modulator that modulates a carrier wave using the serial signal obtained by the parallel-serial converter 6 as a modulation signal.

In other words, as shown in the time chart in Figure 3,
The master station 1 sends inquiry signals b1, b2...bn to the slave stations 21, 22, .
However, when an inquiry signal b1 to the slave station 21 is first transmitted, the slave station 21 uses the slave station identification code included in the inquiry signal to
After determining that the inquiry signal is for the slave station 21, it transmits the measurement data B1 of its own station 21 to the master station 1.

Subsequently, the inquiry signal b2 is transmitted from the master station 1 to the slave station 22, and the slave station 22
transmits measurement data B2 of its own station 22 to the master station 1.

Thereafter, when the slave station 2n transmits the measurement data Bn in the same manner, the slave station 21, slave station 22... slave station 2n again sends an inquiry signal from the master station 1 and each slave station 21 to 2n in this order.
Transmission of measurement data from 2n is repeated.

As a result, on the multi-drop line, the
As shown, the inquiry signals b1, b of the master station 1
2...bn and the response signals B1, B2...Bn of the plurality of slave stations 21, 22...2n are arranged alternately, and the disadvantage is that it takes a long time for the transmission of the response signal to go around from the slave station 21 to the slave station 2n. There is.

(d) Object of the Invention An object of the present invention is to shorten the time it takes for measurement data to be transmitted from a plurality of slave stations to a master station once in a telemeter system connected by a multi-drop line.

(e) Structure of the Invention In other words, the telemeter terminal device of the present invention is connected by a multi-drop line that branches signals from a master station 1 to a plurality of slave stations 21 to 2n over the same line, and transmits measurement data of the own station. A telemeter terminal device installed in each slave station of a telemeter system that transmits data to a master station 1, and a memory that stores in advance the order in which measurement data of the own station is transmitted to the master station 1 and a value representing the number 21 of the own station. 10, a counter 9 that detects the carrier wave of the simultaneous command from the master station 1 and starts counting a constant clock, and a comparison that compares the counted value of the counter and the stored value of the memory to determine when they match. By transmitting the measurement data of the local station 21 to the master station 1 based on the output of the comparison unit, a plurality of slave stations 21 to
2n sequentially transmit their own measurement data to the master station 1.

(f) Examples of the Invention Next, the gist of the present invention will be specifically explained using examples.

FIG. 4 is a block diagram showing the configuration of an embodiment of the present invention. In the figure, the same reference numerals as in FIG. 3, which is modulated and transmitted by the master station 1 (not shown), and is transmitted via a multi-drop line which branches the signal to other slave stations as well. Carrier wave detection detects the carrier wave of the control signal C of the simultaneous command. 9, after resetting the count value to 1 by a reset signal generated by the control signal detection section 12 described later, a clock of a constant frequency is counted at the falling edge of the carrier detection signal obtained by the carrier detection section 8. This is a counter for 10 and 11 are the count value of the counter 9 and a plurality of slave stations 21, 22...2n
10 constitutes a checking means for comparing the data transmission time order and station number predetermined for each of the slave stations, and 10 represents a value representing the data transmission time order and station number predetermined for the slave station. 11 is a comparison unit that compares the count value of the counter 9 with the stored contents of the memory 10 and generates a matching signal when the two match; 12 is a comparison unit that detects a control signal transmitted from the master station 1 and converts it into a counter; This is a control signal detection section that generates a reset signal for the control signal 9.

First, 1, 2...n are stored in the memory 10 as the predetermined data transmission time order for each slave station 21, 22...2n.

Further, as shown in the time chart of FIG. 5, when the master station starts collecting measurement data of each slave station and every time the transmission of measurement data by the plurality of slave stations 21, 22...2n goes around, the master station 1 Send control signal C. The control signal detecting section 12 of the output of the demodulating section 3 of the receiving section of the slave station 21 detects this control signal C and generates a reset signal, and the count value of the counter 9 is reset to one.

As a result, in the slave station 21, since the count value of the counter 9 and the stored content of the memory 10 match, the comparator 11 generates a coincidence signal, and the parallel-to-serial converter 6 and the modulator 7 of the transmitter convert the measured data B1 is applied to the multi-drop line and transmitted to the master station 1.

When the transmission of the measurement data of the slave station 21 is completed in this way, the count value of the counter 9 of the slave station 22 becomes 2.
Similarly, the measurement data B2 is sent from the slave station 22.
is transmitted, and when the transmission by the slave station 2n is completed in the same manner, the transmission is repeated from the slave station 21 again.

The arrangement of each transmission signal on the multi-drop line is shown in FIG. 5e, and as can be seen by comparing it with FIG. The time it takes to complete one cycle can be significantly shortened.

(g) Effects of the Invention As explained above with reference to the embodiments, according to the present invention, in a telemeter system connected by a multi-drop line, measurement data can be transmitted from multiple slave stations to a master station until one cycle is completed. time can be reduced.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of a telemeter system connected by a multi-drop line, Fig. 2 is a block diagram showing the configuration of a conventional example of a telemeter terminal device, Fig. 3 is an explanatory diagram of problems in the conventional example, and Fig. 4 is a block diagram of a telemeter system connected by a multi-drop line. The figure is a block diagram showing the configuration of an embodiment of the present invention, and FIG. 5 is an explanatory diagram of the effects of the embodiment. In these figures, 1 is the master station, 21, 22...
2n is a slave station, 8 is a carrier wave detection unit, 9 is a counter,
10 is a memory, and 11 is a comparison section.

Claims (1)

[Claims] 1 Multiple slave stations 21 to 2n on the same line from the master station 1
In a telemeter terminal device installed in each slave station of a telemeter system that is connected by a multi-drop line that branches signals to the master station 1 and transmits the measurement data of the own station to the master station 1, the telemeter terminal equipment transmits the measurement data of the own station to the master station 1 in advance. A memory 10 that stores values representing the data transmission order and the own station number 21, a counter 9 that detects the carrier wave of the simultaneous command from the master station 1 and starts counting a constant clock, and a counter 9 that starts counting at a constant clock. It is equipped with a comparison section 11 that compares the numerical value with the value stored in the memory and determines when they match, and transmits the measurement data of the own station 21 to the master station 1 based on the output of the comparison section. A telemeter terminal device characterized in that a plurality of slave stations 21 to 2n sequentially transmit their respective measurement data to a master station 1 in response to a single transmitted command.