JPS586998B2 - Enkakusokutei Hoshiki - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a telemetry method that collects measurement data at one location when there are many points to be measured.

For example, when trying to remotely measure the temperature or pressure inside a mine shaft or tunnel at regular intervals, or when trying to remotely monitor the gas pressure inside a gas-filled transmission cable at regular intervals, Measuring devices including temperature and pressure sensors are installed at intervals in mine shafts, tunnels, or transmission cables, and data are collected regularly or as needed from a data collection device commonly installed in these measuring devices. The measuring device is sequentially called up to collect measurement data.

FIG. 1 shows an outline of a conventional measurement method for measuring a large amount of data to be measured in this way.

In FIG. 1, ST is a data collection device (hereinafter referred to as a master station).

), T1 to Tn are measuring devices (hereinafter referred to as slave stations).

), CA is a transmission cable, and in the master station ST, A is a power feeding section, B is a calling section, and C is a processing section.

Conventionally, operating power is supplied to the slave stations T1 to Tn from the power supply section A of the master station ST via the transmission cable CA, and the slave stations T1 to Tn
The measurement data obtained at Tn is sent to the processing section C of the master station ST via the transmission cable CA, and is subjected to data processing.

Furthermore, the calling section B has a low frequency oscillator that generates a plurality of frequency signals, one for each of the slave stations T1 to Tn.
frequency signals are assigned.

The slave stations T1 to Tn each have a response unit including a tuning fork filter, and only the slave stations having tuning fork filters corresponding to the frequency signal sent from the calling unit B via the transmission cable CA respond and perform measurement on the master station ST. configured to send data.

The master station ST can call the slave stations T1 to Tn periodically or sequentially whenever the need arises to obtain measurement data.

Such conventional measurement methods require multiple highly accurate oscillators in the calling unit B, and stable tuning fork filters in the slave stations T1 to Tn, which not only complicates the circuit configuration but also increases the Since the tuning fork filter requires a different resonance frequency for each of the slave stations T1 to Tn, there is a drawback that the slave stations are not compatible with each other.

In addition, since the frequency signal from the calling unit B is sent to each slave station T1 to Tn via the transmission cable CA, an amplifier is required to amplify the frequency signal as appropriate in consideration of the attenuation caused by the cable CA. Conventional measurement methods have various drawbacks, such as CA requiring many lines such as a power line, a call line, and a measurement data transmission line.

Also, as a method for specifying one of a plurality of measurement circuits, has a method been proposed in which a selection code is given to each measurement circuit and the selection code is sent out in parallel to specify it?
This method requires a parallel transmission line for the selection code, separate from the power supply line and the data transmission line, and also requires a code discrimination circuit within the measurement circuit, which has the disadvantage of complicating the system.

The present invention has been made in order to eliminate the above-mentioned drawbacks of the conventional technology, and provides a remote measurement method that can collect measurement data from a large number of measured points at one place with a simple circuit configuration and a small number of cables. It is an object.

For this purpose, in the present invention, a slave station to be operated is designated by supplying power to a plurality of slave station selection cables that are combined in advance, and the measurement data from the designated slave station is transmitted to the slave station. All signals are transmitted to the master station using a common transmission cable.

Embodiments of the present invention will be described in detail below with reference to FIGS. 2 and 3.

FIG. 2 is a circuit diagram showing an embodiment of the present invention, where ST is a master station and T1 to T60 are slave stations (this embodiment shows a case where there are 60 slave stations).

), CA is a transmission cable.

In the master station ST, CT1 to CT6 are slave station selection terminals, D
T1 and DT2 are data receiving terminals.

In the transmission cable CA, ct1 to ct6 are slave station selection cables (hereinafter referred to as slave station selection cables).

), dt1, and dt2 are data transmission cables.

Slave stations T1 to T60 are all configured with the same circuit, a, b and C are selected terminals, d and e are theta transmission terminals, Q is a switching transistor, R1 and R2 are resistors, and D is a current control terminal. A diode S for preventing wrap-around is a measurement circuit including sensors for temperature, pressure, etc.

Figure 3 shows the relationship between the operations of slave stations T1 to T60 and the power supplies sent to slave station selection terminals CTI to CT6 of master station ST. (+) and (0) indicate the corresponding slave station selection terminals, respectively. The terminal is the operating voltage and ground of the measurement circuit S, and a blank column indicates that nothing is applied to the corresponding slave station selection terminal, that is, it is high impedance to the power supply. Station selection terminals CT1 and CT2
When (+) is supplied to the slave station selection terminal CT3 and (0) is supplied to the slave station selection terminal CT3, it indicates that the slave station T1 is activated.

FIG. 3 shows the relationship between the combinations of slave station selection terminals CT1 to CT6 (slave station selection cables ct1 to ct6) and the selected slave stations for all slave stations T1 to T60. For the above combination, slave station selection terminals CT1 to C
If the combination of T6 itself is different from each other (for example, the slave station T
1 and the combination for slave station T2), and the combinations themselves are the same but the characteristics of the power supplies connected to them are different (relationship between the power supply lineman and the connection There is a difference in whether the ground wire (0) is connected) combinations (for example, the relationship between the combination for slave station T1 and the combination for slave station T5), and the combination of slave station selection cables in the present invention refers to both of the above cases.

As mentioned in the conventional example, the slave stations T1 to T60 are installed at appropriate intervals in mine shafts, tunnels, transmission cables, etc., and the master station ST is installed at monitoring stations, data collection stations, etc., and transmits data between them. Connected by cable CA.

Now, for example, when measurement data of the installation location of the slave station T1 is required, as shown in FIG.
When (0) is applied to T3, the power as these slave station selection signals is applied to the selected terminals a, b and c of the slave station T1 via the slave station selection cables ct1, ct2 and ct3, and the selected terminal b and c have a (+) potential, and the selected terminal a has a (0) potential.

Therefore, the base of the transistor Q is connected to the (+) potential through the resistor R1, and the collector is connected to the (+) potential through the measuring circuit S.
The emitter is connected to the potential via diode D and resistor R2 (
0) potential, the transistor Q becomes conductive, and the operating current of the measuring circuit S changes from the slave station selection cable ct1 (+) to the selected terminal C to the measuring circuit S to the transistor Q (collector to emitter) to the resistor R.
2 - Diode D - Selected terminal a - Slave station selection cable c
The current flows along the path t3(0), and the measurement circuit S is activated.

The measurement data obtained by the operation of the measurement circuit S is sent to the data transmission cable dt via the data transmission terminals d and e of the slave station T1.
1 and dt2, and the master station ST receives this measurement data via data receiving terminals DT1 and DT2.

As is clear from FIG. 3, the power source that activated the slave station T1 is used at the same selected terminals a to T60 in the other slave stations T2 to T60.
c is not applied at the same time, or the other slave stations T5 and T21 that are applied at the same time do not apply the same polarity to all selected terminals a to e, so the other slave stations T2 to T60 operate. Never.

For example, when operating the slave station T20 to obtain its measurement data, apply a (+) potential to the slave station selection terminal CT1.
Apply (0) potential to the slave station selection terminal CT5, and
If the (+) potential is sent to each of the terminals 6 and 6, (0) will be sent to the selected terminal a in the same way as when the slave station T1 is activated.
A (+) potential is applied to the selected terminals b and c, and the slave station T20 operates.

The measurement data is then sent to the master station ST via the same data transmission cables dt1 and dt2 as used when the slave station T1 is in operation.

The diodes D in the slave stations T1 to T60 prevent the transistor Q from being biased in the opposite direction between its base and emitter or between its collector and emitter, thereby preventing the transistor Q from being destroyed.

That is, for example, when operating the slave station T5, a voltage of (0) is applied to the slave station selection cable ct2.
At t3, a (+) potential is sent out, and this potential is also applied to the selected terminals b and a of slave station T1, respectively.

However, since the diode D of the slave station T1 is in the opposite direction to the direction of the current flowing due to this potential, the diode D becomes non-conductive and the base of the transistor Q
Since no reverse voltage is applied between the emitters, the transistor Q will not be destroyed.

As explained in detail above, the present invention provides a combination of N slave station selection cables among M slave station selection cables (M>
According to the present invention, (A) When a slave station is called, the slave station is specified by the slave station, and the measurement data is collected in one place using a common data transmission cable. All you have to do is send power to the slave station selection cable that corresponds to the slave station you want to use.
There is no need for a special calling circuit having an oscillation circuit or the like as in the prior art, and there is no need for a parallel code transmission line for the slave station selection code between the master station and the slave stations.

(B) Since power is supplied to the slave stations by the slave station selection signal, there is no need for a dedicated power line between the master station and the slave stations to supply only operating power, and all slave stations other than the called slave stations receive power. It is economical because it does not consume

(C) Since there is no need for a response unit for a calling signal as described in the conventional example, there is no need for special parts such as a tuning fork filter.

(D) All the slave stations have the same circuit configuration, so they are mutually compatible and do not require individual adjustment of the slave stations.

(E) Two or more slave stations will not operate at the same time;
In addition, since the master station can determine which slave stations are in operation, measurement data can be transmitted using a common transmission cable.

The present invention has various advantages such as, and has extremely remarkable effects.

In this embodiment, the number M of slave station selection cables is set to 6, and the number of combined cables N is 3 to selectively specify 60 slave stations. The number N of selected combinations for specifying a slave station or the number of installed slave stations is a matter to be appropriately determined depending on the number of locations to be measured (however, the relationship M>N≧2 is required).

), it is clear that the difference in these numbers does not change the gist of the present invention.

Further, according to the embodiment shown in FIG. 2, the measuring circuit S is used as a collector load of the switching transistor Q. However, if this is made into an emitter load, the usual benefits obtained with a transistor circuit with a grounded collector, such as the measuring circuit The advantage is that S can be driven with a constant current.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram showing a conventional telemetry system, Fig. 2 is a circuit diagram showing an embodiment of the present invention, and Fig. 3 shows the relationship between the power supply sent to the slave station selection terminal and the slave station in operation. This is a table showing relationships. Main symbols: ST... Master station, T1 to Tn (T60
)...Slave station, CA...Transmission cable,
dt1, dt2...Data transmission cable, ct
1~ct6...Slave station selection cable, S...
...Measurement circuit, Q...Switching transistor.

Claims (1)

[Claims] 1 Consisting of a measurement circuit and a power supply unit, a plurality of slave stations installed at a plurality of measured points, and selecting and operating the plurality of slave stations,
In a telemetry system comprising a master station that collects measurement data from the activated slave station, M slave station selection cables are provided between the slave station and the master station, N of the M slave station selection cables (M>N≧2, M
, N is a positive integer) are selected and connected to each power supply unit of the plurality of slave stations so that the combinations thereof are different among the plurality of slave stations, and the master station selects the M slave stations. The structure consists of selecting N cables from among the cables and connecting them to the operating power source, and by sending operating power from the master station to the N selected slave station selection cables, the selection of slave stations and the slave station A remote measurement method characterized by simultaneously supplying power to the