JPS61208928A - Two-wire remote control system - Google Patents

Abstract

PURPOSE:To attain two-way communication without using a transformer by providing a diode bridge and an LPF to a remote controller side receiving a DC power from a cable and connecting a transceiver between them. CONSTITUTION:Power is applied to a power supply 1B of plural remote controllers RCTY from a DC power supply 1A of a main controller MCTX and two-way communication for a control signal is attained by superimposing an AC signal (f) on the control signal through the cable E. In this case, the MCTX side is provided with an inductance L1 blocking the signal (f) from the output of the power supply 1A and the transceiver 2A is connected between the cables E via a capacitor C1. At the RCTY side, a DC power is applied to the device 1B via a full wave rectifier diode bridge DB and an LPFL2 and the transceiver 2B is connected between the DB and the L2 via a capacitor C2. Since a DC current flows always to the DB, the operating point of the diodes is biased, the nonlinearity is neglected, the loss of the signal (f) is less and the cables are made nonpolar.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention can be applied to either a main controller as a remote controller provided on an equipment side such as a gas hot water supply facility, or a remote controller provided on a hot water faucet side. A two-wire remote controller system that can communicate control signals in both directions so that you can control the equipment.
Specifically, control is performed between the main controller and a plurality of remote controllers that are supplied with power from the DC power supply of the main controller via the two-wire cable for power supply, using an AC signal superimposed on the two-wire cable for power supply. The present invention relates to a two-wire remote control system configured to bidirectionally communicate signals.

[Conventional technology]

This kind of two-wire remote control system mentioned above is
When connecting the main controller and remote controller, in order to reduce the number of connection signal lines, an AC signal is superimposed on the power supply cable to the remote controller, and power is sent to the remote controller via this power supply cable. At the same time, the main controller and the remote controller are configured to be able to bidirectionally communicate information such as control signals using superimposed alternating current signals.

Therefore, at least on the remote controller side, it is necessary to separate the DC signal for power supply and the AC signal for communication, which are superimposed on the same cable. and communication AC signal (f
), a transformer (TI), ('
rz) is used, and this transformer (TI), (Tz)
are capacitively coupled in parallel to the power supply cable CF, '') using a capacitor (CI) (C2), etc., to connect the main controller (X) and remote controller (Y) to each transmitting/receiving device (2A), (2B). ) was configured so that only the communication AC signal (f) was input/output.

[Problems to be Solved by the Invention] However, the conventional configuration described above has the following disadvantages, and there is room for improvement.

In other words, when a transformer is used as a means for separating a DC signal for power supply and an AC signal for communication, as the number of remote controllers that serve as a load on the power supply cable increases, the amplitude of the superimposed AC signal becomes larger than the load. Since the transmission output is attenuated by a transformer or the like, it is necessary to increase the transmission output to some extent, but there is a limit to its level because it is limited by the DC power supply voltage for power supply. Also, if you add a remote controller later,
Due to the increased load, the waveform distortion of the transmitted signal increases, resulting in transmission errors, the distortion components generating harmful noise, and the transformer itself sensing the noise. In addition, the inductance and capacitance components of the cable itself will affect the impedance of the communication signal line, and the signal tuning point by the transformer will be significantly shifted, resulting in a large attenuation of the received signal, or depending on the configuration of the transmitter/receiver, the signal There is also the inconvenience that the frequency may shift and communication may not be possible properly. Therefore, in order to design a device so that the signal transmission efficiency does not deteriorate, the design of the transformer used is extremely critical, and since it is difficult to make it smaller, it is difficult to make the remote controller more compact. Not only was this not possible, but it also had the disadvantage of being expensive.

The present invention has been made in view of the above-mentioned circumstances, and its purpose is to enable two-way communication using a power supply cable in the same way as before without using a transformer, and to enable bidirectional communication on the remote controller side. The purpose is to simplify the cable connection to.

[Means for solving problems]

The two-wire remote control system according to the present invention is characterized in that the power supply device on the remote controller side is connected to the cable via a full-wave rectifier diode bridge and a filter that removes the alternating current signal, and
A transmitting/receiving device is capacitively coupled to the connection between the diode bridge and the filter, and its functions and effects are as follows.

[For production]

In other words, by passing the DC power signal and communication AC signal transmitted by the power supply cable through a full-wave rectifier diode bridging, the power supply DC signal flows one-way from the main controller to the remote controller. The signal flow direction is controlled so that the AC signal for communication is bidirectional, and the DC signal for power supply is separated into one direction by a diode bridge, and the AC signal for communication is attenuated by a filter. This function prevents the remote controller's power supply unit from malfunctioning due to communication AC signals superimposed on the power supply line, and separates the signal system so that the power supply unit does not become a load for communication AC signals. . and,
By capacitively coupling a transmitting/receiving device to the connection between this filter and the diode bridge, the power supply is not affected by the impedance of the power supply cable, load power supply device, other remote controller, etc. This allows communication AC signals superimposed on the cable to be sent and received.

Additionally, since DC power is supplied to the remote controller side power supply via the diode bridge, even if the polarity of the cable to this diode bridge is reversed, the polarity of the power supplied to the remote controller side power supply will be automatically changed. The polarity is reversed, and the polarity of the cable and remote controller power supply becomes non-polarized.

Note that communication signals are input and output through the diode, and since direct current always flows through this diode in conjunction with the power supply, the operating point of the diode is biased, and its nonlinearity is Since it operates with almost negligible effects, the signal loss passing through this diode can be made extremely small, distortion of the transmitted signal can also be maintained at an almost negligible level, and unnecessary noise etc. It does not generate any noise or detect any noise.

〔Effect of the invention〕

Therefore, if the transmitting level and receiving sensitivity of the transmitter/receiver are the same as before, the signal quality will be significantly improved, making it possible to minimize malfunctions and significantly extend the transmission distance. . On the other hand, if the same signal quality as before is sufficient, the transmission level can be significantly lowered or the reception sensitivity can be lowered, making it possible to simplify the configuration of the transmitter/receiver and make the remote controller more compact. .

In addition, in addition to simultaneously transmitting power supply and communication signals to the remote controller side via the same power supply cable, there is also a power supply cable that transmits direct current for input/output via the full-wave rectifier diode bridge. Regardless of the cable polarity, the connection polarity to the remote controller side power supply device is automatically maintained in a constant relationship, so it is necessary to consider the cable polarity of both the power supply and communication AC signals during wiring work. I was able to make it completely non-existent.

〔Example〕

Embodiments of the present invention will be described below based on the drawings.

As shown in Figure 1, the output (DC) of the DC power supply (1A) of the main controller (X) is connected to the communication AC signal (f).
A two-wire power supply cable (E) is connected to the two-wire power supply cable (E) via an inductance (Ll) to function as a cutoff filter and to prevent the DC power supply (LA) from becoming a load on the communication AC signal (f). Connect to the hot side (Eh) of the remote controller and ground the cold side (Ec), and basically supply operating power to the remote controller (Y) side via this two-wire power supply cable (E). It is configured to supply Then, the inductance (L2
) and the connection point (α) with the hot side <eh> of the cable (E)
) to the communication AC signal (f) via the capacitor (C1).
The transmitter/receiver (2A) is capacitively coupled, and the remote controller (2A) is connected via the two-wire power supply cable (E).
While supplying power to the control device (3), the communication AC signal (f) superimposed on the power supply cable (E)
It is configured so that data and control signals for A) and (3B) can be transmitted bidirectionally.

On the other hand, on the remote controller (Y) side, a diode bridge (DB) and the main controller (X)
Similarly to the side inductance (Ll), the inductance (
A power supply device (1B) is connected to the power supply cable (E) via the power supply cable (L2) so that power for operating the remote controller (Y) is obtained from the power supply device (1B), and the Main controller (X)
For surveyors, connect the remote controller (Y) lateral receiver (2B) to the connection point (β) between the diode bridge (DB) and inductance (L2) via the capacitor (C2).
) are capacitively coupled, and the superimposed communication AC signal (f ), the main controller (X) side control device (3A) and the remote controller (Y
) side control device (3B) so that data and control signals can be transmitted bidirectionally.

By connecting another remote controller (Y) in parallel to the two-wire power supply cable (E), it is possible to connect not only multiple remote controllers (Y) and the main controller (X) but also multiple remote controllers. Controller (Y
) can also be configured to enable bidirectional communication.

The operation of the diode bridge (DB) will be explained below.

That is, if the polarity of the power supply cable (E) is connected correctly, as shown in FIG. 2 (A),
The remote controller (
Y) side power supply (1B) and cable (E) hot side (
Rh) is connected, and the ground potential is connected to the cold side (Ec) via one third diode (D3) connected to the ground potential side of the power supply device (1B). On the other hand, when the power supply cable (E) is connected with the polarity reversed, it is connected to the connection point (β) of the diode bridge (DB), as shown in FIG. 2 (0). The remote controller (Y) side power supply unit is connected via the other fourth diode (D4)! (1B) and the hot side (Eh) of the cable (IE) are connected, and the other first diode (Dl) is connected to the grounded side of the power supply (1B).
A ground potential is connected to the cold side (Ec) via.

Therefore, no matter how the polarities of the two power supply cables (E) are connected, the remote controller (Y)
Power is normally supplied to the side power supply unit (1B), and the cable (I remote controller (Y)
There is no need to consider the connection polarity.

Furthermore, the relationship between the transmitter/receiver (2B) connected to the diode bridge (DB) via the capacitor (C2) and the hot side (Rh) of the cable (E) is automatically maintained, and the cable The connection polarity of (E) does not affect the transmission and reception of the communication AC signal (f) superimposed on the hot side (Eh) of this cable (E).

Next, the operation for bidirectional communication between the main controller (X) and the remote controller (Y) will be described.

That is, when transmitting from the main controller (X) to the remote controller (Y), the capacitor (C5
) is input to the remote controller (Y) and both transmitting and receiving devices (2b) via the second diode (D2) or fourth diode (D4) and the capacitor (C2). The input current flows through the third diode (D3) or the first diode (0I) to the main controller (X) and both transmitting and receiving devices (2A
) is formed. Then, the DC component (I
Current change (±I) due to change in AC signal (f) with respect to o)
+), the AC signal (f) is separated and extracted as a voltage signal (νI). In addition, when transmitting from the remote controller (Y) to the main controller (X), the current change (±
The same is true except that the direction of r+) is reversed.

By the way, the diode bridge (DB) is an element that causes signal transmission loss to both the transmitting and receiving devices (2A) and (2B), but the power supply current (Io) is constantly flowing through the diode bridge (DB). Because it is flowing, it becomes completely conductive, and almost no voltage fluctuation occurs between its input and output, so the transmission loss for the AC signal (f) can be almost ignored. .

Note that when two-way communication is performed using the communication AC signal (f) superimposed on the power supply cable (E), when one of the transmitter/receivers (2A) and (2B) is in the transmitting state, The AC signal (
f) is amplitude-modulated and used in a half-duplex serial transmission format. And, as shown in Figure 3,
The state in which the AC signal (f) is output is "H" level.
By setting the state where the AC signal (f) is not output as "L" level, transmitting the communication data serially in digital format, and having the content determined in each control device (3^), (3B), It sends and receives various control signals and data.

[Brief explanation of drawings]

The drawings show an embodiment of the two-wire remote control system according to the present invention, and FIG. 1 is a block diagram showing the overall configuration, FIG. 2 (<) and (TI) are diagrams explaining the operation of the diode bridge, and FIG. 3 is an explanatory diagram of the transmission signal on the cable,
FIG. 4 is a block diagram showing a conventional configuration. (χ)... Main controller, (Y)...
...Remote controller, (E) ...Two-wire cable for power supply, (1A) ...DC power supply, (1B) ...Power supply device, (f)・・・・・・
AC signal, (DB)...Full-wave rectification diode bridge, (Lx)...Filter, (β)...
...Connection part, (2A), (2B)...
Transmitting/receiving device.

Claims (1)

[Claims] Between the main controller (X) and a plurality of remote controllers (Y) that are supplied with power from the DC power supply (1A) of the main controller (X) via the two-wire cable (E) for power supply, 2-wire cable (E)
This is a two-wire remote control system configured to bidirectionally communicate control signals using an alternating current signal (f) superimposed on the It is connected to the cable (E) via a rectifying diode bridge (DB) and a filter (L_2) that removes the alternating current signal (f), and the diode bridge (DB) and filter (L_2)
A two-wire remote control system in which a transmitter/receiver (2B) is capacitively coupled to the connection (β) with _2).