JPS5828956B2 - Time division multiplex transmission method - Google Patents

Description

[Detailed Description of the Invention] The present invention provides a control section A and a plurality of controlled sections B1...
In a remote monitoring control system in which Bn is connected by a signal transmission line l, at least the control unit A connects the controlled units B1B2...
...The transmission pulses for address signals, control signals, etc. sent to Bn are multipolar signal transmission, and the signal content of one pole and the same signal content are transmitted alternately from the other pole. The connection of the control section B1...Bn with the transmission line l is made non-polarized, and the full-wave rectified output of the transmission pulse is used as a driving power source for the controlled section B1...Bn. The purpose of the time-division multiplex transmission system, which is characterized by its characteristics, is to create a simple and inexpensive circuit configuration, eliminate troubles caused by incorrect connections during wiring work, and eliminate the need for emergency transmission pulses in controlled parts. It is an object of the present invention to provide a time division multiplexing transmission system that can efficiently extract power and perform high-quality waveform transmission.

FIG. 9 shows an example of a time chart in a conventional time division multiplex transmission method for a remote monitoring and control system.

This FIG. 9 shows a time chart in the first controlled unit Bi, showing the transmission time Tt transmitted from the control unit A and the reply time period Tr sent back from the controlled unit Bi.
This is an example per channel consisting of.

In addition, SPi in the same figure is a start synchronization pulse, Pl...
... Pm is, for example, a pulse train that is address encoded with a binary pulse code and a pulse train that gives the control contents. In this example, the start synchronization pulse SPi and each of the above pulse trains are separated by a difference in pulse width, and in each of the above pulse trains, II OI + double signal ■111 signal are distinguished by the difference in pulse width, and P11 to 3 in the figure are "
10゛1, P2. Pm indicates "I II.

Ql...Q3 is a display signal pulse that returns the state of the controlled section Bi, and in the conventional example shown in the figure, three monitoring items are sent back to the control section A.

Further, SPi+1 is the i-th + 1st controlled part B 1
+1 start synchronization pulse, signals are subsequently cyclically transmitted and received between each controlled section B1...Bn and the control section A in the same manner as described above.

Generally, in the remote monitoring and control system as described above, the transmission line system is complicatedly branched as shown in Fig. To do so would unnecessarily cause signal attenuation, and it is practically difficult to measure matching by inserting a matching resistor.

Therefore, if a matching resistor is not inserted in the transmission of a pulse signal as shown in the conventional example time chart of FIG. 9, the waveform will be distorted as shown by the chain line in FIG. 10.

That is, when a rectangular pulse as shown by the solid line in the figure is injected from the control unit A into the transmission line l, the waveform is disturbed due to complicated reflections of the propagating waves on the transmission line l, and for example, the waveform as shown by the chain line in Fig. 10 is distorted. It will be received by the control unit Bi.

However, if the above-mentioned disturbed waveform is directly input to the level detection circuit of the receiving circuit, a problem arises in that the width of the pulse changes or a part of the pulse is missing.

In order to prevent this, for example, a coupling method as shown in FIG. 11 can be obtained.

(In the figure, 11 is the plus side, 12 is the minus side, and these 11
12 constitutes a transmission line l.

) That is, the energy of the overshot portion of the pulse rising vibration d1 in FIG. 10 is the Zener diode ZD,
The amplitude of the oscillating voltage of the entire d1 is suppressed, and the pulse falling oscillation d2 is also suppressed by the diode D1 for the same reason, so that the overall waveform approaches the original rectangular pulse wave shown by the solid line and has a good shape. Transmission is possible.

(Rc in the figure is a receiving circuit.

) However, when the connection between the controlled part and the transmission line l is made non-polarized, the diode D1 is connected in parallel to the transmission line l, so the circuit connection as shown in Fig. 11 does not work as described above. It is not possible to obtain the desired waveform shaping effect.

That is, even if a bridge circuit is inserted in parallel with the transmission line 1 to achieve non-polarization, the waveform shaping described above cannot be performed.

The present invention has been provided in view of the above-mentioned points, and provides a time division multiplex transmission system that can simultaneously satisfy both the above-mentioned waveform shaping effect and non-polarization of the transmitted signal.

An embodiment of the present invention will be described in detail below with reference to the drawings.

2 and 3, a large number of controlled parts B1...B are connected to the transmission line l connected to the control part A as shown in FIG.
FIG. 2 shows an example of a logic circuit of a control unit A and controlled units B1, . . .

In the block diagram of the control unit A shown in FIG. 2, 1 is a clock pulse circuit, and 2 is a synchronization signal circuit that generates synchronization signals to each circuit using clock pulses from the clock pulse circuit 1, including start synchronization pulses and address code signals. , control command signals, display signals, etc., which are necessary for controlling and displaying each address per address, are outputted along with a programmed sequence. When finished, the circuit returns to the beginning and outputs a synchronizing signal in the same way.

3 is a counter that counts one pulse output from the synchronizing signal circuit 2 in a signal group per channel and notifies the decoding circuit 4 and shift register 5 of the channel address of the signal to be sent or received, and is a binary counter. -Output is output to the output terminal.

A decoding circuit 4 receives and decodes a binary signal indicating the address from the counter 3.

Reference numeral 5 denotes a shift register with a parallel manual serial output that reads a binary signal indicating an address from the counter 3 from a parallel input terminal, shifts it into series according to a pulse from the synchronizing signal circuit 2, performs parallel-to-serial conversion, and generates an address code signal. It is.

Reference numeral 6 denotes a start synchronization pulse generation circuit which generates a start synchronization pulse at the beginning of each signal group in synchronization with the synchronization signal from the synchronization signal circuit 2 and generates a pulse having a longer pulse length than other signals.

7 is a switch block 24 on the control command path line 22.
Alternatively, the control command set by the analog switch 9 or the analog switch 25 etc.
This is a parallel input/serial output shift register that reads the signal from the parallel input terminal when it is sent out by controlling 0, serially shifts it in response to the synchronization signal from the synchronization signal circuit 2, and encodes the control command.

8 is a shift register 5, a start synchronization pulse generation circuit 6
This is a transmission control circuit that adds the signals from the shift register 7 and controls the output signal using the signal from the synchronization signal circuit 2.

A coupler 19 is a circuit for sending a signal from the transmission control circuit 8 to the transmission line 1 or transmitting a display signal from the transmission line 1 to the display signal reception control circuit 18.

However, the display signal reception control circuit 18 transmits the signal from the coupler 19 to the pulse width detection circuit 16 and the clock pulse circuit 17 when a reception permission signal is output from the synchronization signal circuit 2.

This clock pulse circuit 17 supplies a clock to the pulse width detection circuit 16 and shift register 13 in order to receive the display signal.

The pulse width detection circuit 16 is a circuit that detects the type of signal by detecting the difference in pulse width of the display signal from the coupler 19 and supplies a clock to the shift register 13. It is a serial input/parallel output shift register for serial/parallel conversion, and operates to send its output to the display signal path line 21.

The display signal thus sent to the display signal path line 21 is a signal obtained by decoding the output of the counter 3 and sent to the gate circuit 11. The signal on the display signal path line 21 is read into the display signal storage circuits 14 and 15 by performing a logical product with the signal read signal and sending the output to the display signal storage circuits 14 and 15, and the display lamp 26 or 27 is turned on or off to display the state of the controlled section B.

The portion surrounded by a broken line 23 in the figure is a display signal processing circuit block.

Next, FIG. 3 is a block diagram of the controlled unit Bi, where l is a transmission line, the control unit A and other controlled units B1...
...Connected to the Bn coupler.

A coupler 32 includes a coupling element between the transmission line l and the logic circuit, a signal level shift circuit, a noise removal filter, a driver for sending out display signals, and the like.

Reference numeral 33 denotes a clock generation circuit, which supplies a clock pulse of a predetermined frequency to the pulse width detection circuit 34 when an input signal is received, and is composed of a multi-by-break circuit with a control terminal.

The pulse width detection circuit 34 counts the number of pulses from the clock generation circuit 33, detects the pulse width from the count result, and determines the type of signal.

Reference numeral 35 denotes a serial-to-parallel conversion circuit consisting of a serial input/parallel output shift register, which reads address codes and control commands to obtain parallel signals.

Reference numeral 36 denotes a coincidence determination circuit that determines whether the address code output from the serial/parallel conversion circuit 35 matches a preset address, and is composed of a switch block and a gate circuit.

37 is a time zone discrimination circuit which receives the signal from the coincidence discrimination circuit 36, stores it when a coincidence signal is received, and further discriminates the display signal sending time and the control signal sending time; when the display time comes, the time zone discrimination circuit 37 A signal is sent to the transmission control circuit 38, the signal from the pulse width detection circuit 34 is selected based on the information from the display contact 31, and the display signal is sent out via the coupler 32.

When a control command comes in, the parallel output of the serial/parallel conversion circuit 35 and the control command reception command from the time zone discrimination circuit 37 are input to the reception control circuit 39, and the control command is transmitted to the relay 30 via a driver etc. .

Next, FIG. 4 shows an example of a time chart of the transmission signal at the time of the sixth controlled unit Bi in an embodiment of the present invention.

In the same figure, SPi, Pl...Pm, SPi+
1 and Ql...Q3 are the same as in the case of the conventional example shown in FIG.

In the time chart of FIG. 4, a bipolar transmission method is adopted in the transmission time period Tt in which a signal is supplied from the control unit A to the controlled unit B1, and the upper (plus side) pulse group S P i+ P 1 ...Pulse group SPi', P1'...Pm showing the same content as Pm
9 is also provided on the lower side (minus side).
This figure is different from the time chart of the conventional example.

FIG. 5 shows the control unit A for the example time chart in FIG.
This is a control system model diagram showing a state in which a controlled part B'i is remotely monitored and controlled from a control part A, in which a start synchronization pulse, an address code signal, and a control command signal are generated by operating a selection control switch a0 in a control part A. A signal is sent from the logic circuit section a2, and the line driver circuit a5. a6 is activated to supply the energy of each power source 831a4 to the transmission lines 121 and 12 in accordance with the signal.

In this control system, the power of each pulse sent from the control section A to the controlled section Bi is used to simultaneously supply power to each circuit of the controlled section B1.

Therefore, in the controlled part Bi, the diode bridge BG and the smoothing capacitor C charge the power supply, and the received signal is input from the circuit of the resistor R1 and the Zener diode ZD to the logic judgment circuit b1, and the relay drive circuit b2 is activated in accordance with the command from the control part A. make it work

The state of the monitoring contact group b4 composed of relay contacts and the like is determined by display signal pulses Q1, Q2, . . . as shown in the time chart of FIG. Create Q3.

Thus, in the control section A, this display signal pulse Q1. Q2. Q
3 is received by the receiving circuit a7 and displayed by the indicator light circuit a8.

Next, the controlled part B1...Bn and the fifth part of the control part A
Examples of coupling circuits corresponding to the control system model diagrams are shown in FIGS. 6 and 8, and will be explained.

First, in the coupling circuit of the controlled parts B1...Bn shown in FIG.
Suppose that we are the ground line.

The received signal transmitted through the transmission line 1112 is first divided by voltage dividing resistors R2 and R3, and then input to the logic circuit M via the nozzle removal capacitor C1 and resistor R5.

Therefore, if the manually received signal is an address signal of one's own address, the logical four-way M is used to store that it is one's own address.

The embodiment shown in FIG. 6 shows an example in which one latch relay is operated.

(Of course, the same applies even if the number of relays increases.) Here, for example, Ll is an ON winding, L2 is an OFF winding, and these two windings L1. Assume that L2 constitutes a latch relay.

If the control command content is "ON", the II I 11 output is output to the output terminal y1 of the logic circuit M, and if it is "OFF", the If I If output is output to the output terminal y2.

Therefore, depending on each control command, the transistor T3
Alternatively, T4 is driven and a voltage is applied to winding L1 or L2 of this latch relay.

Next, when the display signal sending time period Tr begins, the display signal output is output from the output terminal X of the logic circuit M, and the transistor T2
and display signal drive transistor T5, resistor R
1. A display signal pulse is sent to the control section A through a loop of the transmission line 1112, the transistor T1, and the smoothing capacitor C3.

On the other hand, each information pulse signal sent from the control section A is simultaneously used as a power source for the controlled section Bi.

That is, in this example, two smoothing charging circuits are provided, and the constant voltage power supply for the logic circuit is composed of a diode bridge BG, a resistor R4, a smoothing capacitor C2, and a constant voltage diode ZD2. , and a power source for display signal transmission and relay drive is composed of a diode bridge BG, a resistor R6, a smoothing capacitor C3, and a Zener diode ZD1.

FIG. 8 shows an example of the coupling circuit of the control section A,
A start synchronization pulse, an address code signal, etc. are output from the terminal U of the logic circuit N, and the positive voltage is connected to the power supply S.
1. The negative side voltage is sent from the output transistor T8, the power supply S2, and the output transistor T5 to the transmission line l at low impedance.

That is, when the terminal U output is II I II, the transistors T7 and T8 and the transistor T1T2 are turned on, and the transistors T3 and T4 are turned on.

T5 is turned off.

On the other hand, as is clear from the time chart in FIG. 4, in the display signal time period Tr, since the control unit A receives the signal, it is necessary to turn off both the transistors T8 and T5.

Therefore, in the display signal time period Tr, from the output terminal ■If
I II output is output, and in this case, transistors T6 and T1 are turned on, and both output transistors T8 and T5 are turned off at the same time.

The received signal is inputted from a terminal W to a receiving logic circuit (not shown) in the control unit A as a divided voltage of the resistor R0°RIO.

In the figure, R1...R7 are resistors.

Thus, from the control section A to the controlled section B1. B2...
FIG. 7 shows an example of a transmission waveform transmitted to Bn.

As in the case of conventional unipolar signal transmission as shown in Fig. 10, in bipolar transmission as in the present invention, a matching resistor is not included in the transmission system as shown in Fig. 1, which has complex branches. , a waveform disturbance as shown by the chain line in FIG. 7 occurs.

However, in this case, by inserting the diode bridge BG and the Zener diode ZD1 shown in the circuit in FIG. Signals can be received regardless of the polarity of lJ2.

Note that the display signal pulses Q1...Q3 sent from the controlled section Bi to the control section A are controlled by matching the transmission output impedance from the controlled section Bi and the reception impedance of the control section A to matching resistance values. Waveform disturbances are improved.

In other words, from the control unit A to the controlled unit B1...Bi...
...When transmitting to Bn, each controlled unit B1 ...
...Waveform shaping can be performed by inserting matching resistors into all the coupling parts of Bn, but the signal attenuation becomes more significant as the distance from the control part A increases, making it impossible to obtain a receivable signal level. , for this reason, waveform shaping using matching resistors is a good idea.)

However, when transmitting data from the controlled parts B1...Bn to the control part A), a good waveform can be obtained by simply inserting a matching resistor into the control part, as shown in the time chart in Figure 4. Thus, even if the display signal pulses Q1 to Q3 are unipolar signals, good signal transmission can be achieved.

However, when transmitting the display signal pulse Q1... from the controlled part B1...Bn to the control part A, It goes without saying that, like the signal, a plurality of the same signals may be transmitted alternately.

The present invention is constructed as described above, and uses bipolar transmission as a signal during the transmission time period from the control unit to the controlled unit, and moreover, the same signal content is sent alternately to the positive and negative poles. As a result, the coupling method of the controlled part to the transmission line can be made completely non-polarized, and troubles caused by incorrect wiring can be eliminated.
In addition, since the transmitted pulse is always present on the transmission line across the positive and negative poles, the full-wave rectified output of the transmitted pulse makes it possible to obtain one drive power for the controlled part n very efficiently. Moreover, by simply adding a vibration energy absorbing element such as a constant voltage diode to the controlled section, the transmission waveform can be shaped extremely easily, resulting in high-quality signal transmission. has.

[Brief explanation of drawings]

Fig. 1 is a basic block diagram of the remote monitoring and control system, Fig. 2 is a block diagram of a control section according to an embodiment of the present invention, Fig. 3 is a block diagram of the controlled section of the same as above, and Fig. 4 is a block diagram of the same as above. Time chart of the transmission signal, Figure 5 is a control system model diagram as above, Figure 6 is a circuit diagram of the controlled unit coupling circuit as above, Figure 7 is a waveform diagram of the transmission signal as above, Figure 8 is the control system as above. Circuit diagram of partial coupling circuit,
FIG. 9 is a time chart of the conventional example, FIG. 10 is a transmission signal waveform diagram of the same as above, and FIG. 11 is a schematic circuit diagram of the input coupling section of the same as above, where A is a control section, B1...・・B
n is a controlled hook portion, and l is a transmission line.

Claims (1)

[Claims] 1. In a remote monitoring and control system in which a control unit and a plurality of controlled units are connected by a signal transmission line, at least transmission pulses of address signals, control signals, etc. transmitted from the control unit to the controlled units are bipolar signal transmission, In addition, the same signal content as that of one pole is transmitted alternately from the other pole, and the connection with the transmission line of the controlled part is made non-polarized, and the full-wave rectified output of the transmitted pulse is controlled. A time division multiplex transmission system characterized in that it functions as one driving power source for one part.