JPH0444438A - Communication terminal equipment - Google Patents

Abstract

PURPOSE:To eliminate the need for caring for the polarity in the case of connection with a transmission line by using a full wave rectifier circuit to apply non-polarity connection among a transmission circuit, a reception circuit and the transmission line. CONSTITUTION:A reception circuit 5 and a transmission circuit 7 of a communication terminal equipment 2 are connected to a transmission line 4 through a full wave rectifier circuit 16. Similarly, a reception circuit 6 and a transmission circuit 8 of a communication terminal equipment 3 are connected to the transmission line 4 through a full wave rectifier circuit 17. When a DC voltage is applied from the transmission line 4 to an AC terminal, a DC voltage of a same polarity is outputted at all times from a DC terminal regardless of the polarity of the applied DC voltage by the full wave rectifier operation of the full wave rectifier circuit 16. The output voltage is fed to the reception circuit 5 and the transmission circuit 7.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a communication terminal device, and particularly relates to an improvement in a connection portion with a transmission line.

[Prior Art] Conventionally, systems have been known in which signals are transmitted by supplying DC power to a transmission line. Such a system is described, for example, in Japanese Patent Laid-Open No. 59-54345, particularly in FIG. 5 thereof.

FIG. 2 shows the configuration of a signal transmission system having a similar configuration to this system.

The system shown in this figure is composed of a communication power source (1), a communication terminal (parent) (2), a communication terminal (child) (3), and a transmission line (4).

In this figure, only one communication terminal (child) (3) is shown for simplicity, but it is also possible to provide a plurality of communication terminals (child) (3).

The communication power supply (1) applies a predetermined DC voltage to the transmission line (4),
For example, a DC voltage of 24V is supplied.

The communication terminal (parent) (2) and the communication terminal (child) (3) are both connected to the transmission line (4), and have receiving circuits (5) and (6), transmitting circuits (7) and (8), respectively. Transmission control circuit (
9) and (10), controllers (11) and (12)
It is equipped with

That is, communication terminal (parent) (2) and communication terminal (child) (
3) both have a common configuration as communication terminal devices. The difference between the two is that the former controller (11) is connected to a button (13) and a display (14), and the latter controller (12) is connected to a load (16) such as an air conditioner. be.

Furthermore, the transmitting circuits (7) and (8) are circuits that short-circuit their output terminals in response to the voltage supply from the transmission control circuits (9) and (10), respectively. configured. The output ends of the transmitting circuits (7) and (8) are connected to the transmission line (4) by a so-called information outlet (not shown). This connection is made so that the output polarity of the transmitting circuits (7) and (8) matches the polarity of the DC voltage of the transmission line (4).

The receiving circuits (5) and (6) are also connected to the transmission line (4) so that their polarities match, and are constructed of photocouplers for the same reason as the transmitting circuits (7) and (8). . However, the receiving circuits (5) and (6) are the transmitting circuit (7)
and (8) are in the opposite direction. In other words, the receiving circuit (5
) and (6) detect an open/short circuit in the transmission line (4),
The detection results are supplied as signals to transmission control circuits (9) and (10), respectively.

Next, the operation of this system will be explained.

When the button (13) of the communication terminal (parent) (2) is operated, the controller (11) causes the transmission control circuit (9) to start transmission in response to this operation.

The transmission control circuit (9) intermittently supplies voltage to the transmission circuit (7) according to the signal to be transmitted.

When the voltage supplied from the transmission control circuit (9) to the transmitting circuit (7) is interrupted/interrupted, the output end of the transmitting circuit (7) is opened/disconnected.
Short circuited. In response to this, the voltage supplied from the transmission line (4) to the input end of the receiving circuit (6) of the communication terminal (child) (3) is switched between the predetermined voltage E and zero.

The receiving circuit (6) turns on/off in response to this, and its output is input as a signal to the transmission control circuit (10). The transmission control circuit (10) transfers this signal to the controller (12).
Based on this, the controller (12) supplies the load (
15).

Next, consider the case of transmission from the communication terminal (child) (3). In this case, the controller (12) causes the transmission control circuit (]0) to start transmitting a signal depending on the operating state of the load (15), for example.

The transmission control circuit (10) performs transmission using a transmission circuit (8) having the same configuration as the transmission circuit (7) of the communication terminal (parent) (2). Transmission control circuit (9) of communication terminal (parent) (2)
) receives a signal from the transmission line (4) by a receiving circuit (5) having the same configuration as the receiving circuit (6) of the communication terminal (child) (3), and supplies the received signal to the controller (11). In response, the controller (11) causes the display (14) to display the operating state of the load (15), etc.

FIG. 3 shows the structure of a frame related to transmission in this conventional example.

The frame 100 shown in this figure has a self address 11
0, a destination address 120, a control code 130, a message length code 140, data 150, and a frame check code 160.

The self address 110 is set to the source device, and the destination address 120 is set to the address of the destination device. The control code 130 indicates the number of retransmissions for invalid frames, etc., and the message length code 140 indicates the length of data 150 related to transmission. Data 150 is a communication terminal (parent) (2)
When transmitting from to the communication terminal (child) (3), the load (15
) control command value (on/off, etc.) to the communication terminal (child 9 (
When transmitting from 3) to the communication terminal (parent) (2), the load (
15).

In this way, conventionally, data was transmitted between the communication terminal (parent) (2) and the communication terminal (child) (3) via the transmission line (4).

[Problems to be Solved by the Invention] However, in conventional systems, a DC voltage is applied to the transmission line, and the communication terminal device also has polarity.

For this reason, it is necessary to pay attention to the polarity when connecting the communication terminal device and the transmission line. If the polarity is incorrectly connected, signal transmission as described above cannot be performed.

The present invention was made with the aim of solving these problems, and there is no need to pay attention to polarity when connecting to a transmission line, it is possible to avoid failure to transmit signals due to incorrect polarity connection, and it is possible to avoid problems when installing equipment. - The purpose is to provide a communication terminal device that is highly workable during maintenance, etc.

[Means for Solving the Problems] In order to achieve such an object, the present invention provides a full-wave rectifier that always outputs a DC voltage of the same polarity from a DC terminal regardless of the polarity of input to the AC terminal. The AC terminal is connected to the transmission line, the DC terminal is connected to the transmitting circuit and the receiving circuit with matching polarity, and the full-wave rectifier circuit ensures non-polarization between the transmitting circuit, the receiving circuit and the transmission line. It is characterized by being connected.

[Operations] The communication terminal device of the present invention is connected to a transmission line by a full-wave rectifier circuit. This full-wave rectifier circuit always outputs a DC voltage with the same polarity, regardless of the polarity of the input to the AC terminal. This DC voltage is supplied with matched polarity to the transmitting circuit and the receiving circuit through the DC terminal. Therefore, regardless of the connection direction to the transmission line, signal transmission is performed via the transmission line. That is, a communication terminal device is configured in which the polarity related to the connection with the transmission line is non-polar.

[Examples] Hereinafter, preferred embodiments of the present invention will be described based on the drawings. Components similar to those of the conventional example shown in FIGS. 2 and 3 are denoted by the same reference numerals, and description thereof will be omitted.

FIG. 1 shows the configuration of a signal transmission system that employs communication terminal devices (communication terminal (parent) (2), communication terminal (child) (3)) according to an embodiment of the present invention.

In this embodiment, a receiving circuit (5) and a transmitting circuit (7) in a communication terminal (parent) (2) are connected to a transmission line (4) by a full-wave rectifier circuit (16). Similarly, the receiving circuit (6) in the communication terminal (child) (3)
The transmission circuit (8) is also connected to the transmission line (4) by a full-wave rectifier circuit (17).

A feature of the present invention is that the full-wave rectifier circuit (16) and the full-wave rectifier circuit (17) are connected to the transmission line (4) in this way.

The full-wave rectifier circuits (16) and (17) are so-called diode bridges, of which two out of four terminals are AC terminals and the other two are DC terminals.

Taking the full-wave rectifier circuit (16) as an example, of the four terminals, the AC terminal is connected to the transmission line (4), and the DC terminal is connected to the receiving circuit (5).
) and the transmitting circuit (7).

Therefore, a DC voltage is applied to the AC terminal from the transmission line (4). Then, from the DC terminal, a full wave rectifier circuit (16
), the DC voltage is always output with the same polarity regardless of the polarity of the applied DC voltage. This voltage is supplied to the receiving circuit (5) and the transmitting circuit (7).

As a result, if the output polarity of the full-wave rectifier circuit (16) is matched to the polarity of the receiving circuit (5) and the transmitting circuit (7), the relationship between the polarities of the transmission line (4) and the gold-wave rectifier circuit (16), Therefore, there is no need to consider the polarity of the connection of the communication terminal (parent) (2) to the transmission line (4).

For example, when connecting the transmission line (4) and the communication terminal (parent) (2) through an information outlet when installing the system, the full-wave rectifier circuit (16) connects the communication terminal (parent) (2)
Since these are non-polar, they can be connected without matching or mismatching the polarities.

Although the above explanation was exclusively about one communication terminal (parent) (2), the same applies to the communication terminal (child) (3).

Therefore, according to this embodiment, the workability related to the connection is improved, and there is no possibility that signal transmission becomes impossible due to incorrect connection. In this way, it is possible to configure a highly reliable system that is easy to install and maintain.

In addition, the communication terminal device according to this embodiment particularly has a transmission line (4
), it can be applied as is to the conventional system shown in FIG. In other words, the conventional communication terminal (parent) shown in FIG.
2), communication terminal (child) (3), etc. can be mixed in the same system, and compatibility is high.

[Effects of the Invention] As explained above, according to the present invention, since the full-wave rectifier circuit provides non-polar connection between the transmitting circuit and the receiving circuit and the transmission line, there is no need to change the polarity when connecting to the transmission line. There is no need to pay attention to this, and the inability to transmit signals due to incorrect polarity connections can be avoided, improving work efficiency during equipment installation and maintenance.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the configuration of a signal transmission system using a communication terminal device according to an embodiment of the present invention, and FIG. 2 is a diagram showing the configuration of an example of a signal transmission system using a conventional communication terminal device. The figure shown in FIG. 3 is an explanatory diagram of a frame in this conventional example. In the figure, (1) is a communication power supply, (2) is a communication terminal (
(parent), (3) is a communication terminal (child), (4) is a transmission line, (5
) and (6) are receiving circuits, (7) and (8) are transmitting circuits, (9) and (10) are transmission control circuits, (11) and (
12) is a controller, and (16) and (17) are full-wave rectifier circuits. Note that the same reference numerals in the figures indicate the same or equivalent configurations.

Claims (1)

[Claims] A transmission circuit that transmits a signal by shorting/opening between transmission lines to which a predetermined DC voltage is applied according to a transmission request; In a communication terminal device comprising a receiving circuit that receives a signal and a transmission control circuit that issues a transmission request to the transmitting circuit and takes in the signal from the receiving circuit, an AC terminal connected to a transmission line, and an AC terminal connected to the transmitting circuit and the receiving circuit. DC terminals that are connected with the same polarity, and a full-wave rectifier circuit that always outputs a DC voltage of the same polarity from the DC terminal regardless of the polarity of the input to the AC terminal.Full-wave rectification A communication terminal device characterized in that a circuit provides non-polar connection between a transmission circuit, a reception circuit, and a transmission line.