JPH0332151A - Communication equipment - Google Patents

Abstract

PURPOSE:To make a selective call and its reply between communication equipments corresponding with each other through a single data signal line by providing a selective reply input and output circuit outputting a pulse with a pulse width specific to a slave set to a data signal line and detecting a selection signal based on a pulse on the data signal line. CONSTITUTION:A master set 1 is provided with a selection reply input and output circuit 13, which is provided with a transistor(TR) 13a subject to switching control based on a level of an output line 14 of a CPU 5 and with a photocoupler 13b comprising of a photo diode and a photo TR provided between a collector of the TR 13a and a DC power supply (an output of the photo TR is given to the CPU 5 via an input line 15). Similarly a selection reply input and output circuit 16 of the same constitution is provided to each of plural slave sets 8 and the circuit 16 outputs a pulse with a pulse width specific to a slave set to be selected onto a data signal line 19 connected in common and detects a selection signal based on a pulse on the data signal line 19. Thus, even when plural save sets are connected to one and same telephone line, the equipment is coped with without increasing a data signal line.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a communication device that transmits data via a telephone line.

[Conventional technology]

A conventional device of this type is shown in FIG. In the figure, (1) is a base unit, which includes an incoming call detection circuit (2) consisting of a capacitor (3) and a relay (4), a CPU (5), and a contact (6C) on the telephone line. ) and a transmission transformer (7). In addition, (4b) is the above-mentioned incoming call detection circuit (2)
This is the contact point of the relay (4). In addition, (8) the above base unit (
This shows a handset connected to the same telephone line as 1), and this handset (8) has a CPU (9) and a contact point (10) on the telephone line.
d) and a transmission transformer (11), multiple handsets with the same configuration are connected to the same telephone line, and a data signal line (1G) is connected between these CPUs. 12), and the handset with the address corresponding to the handset number specified by the source communication device via the base unit (1) or a predetermined address is connected to the line. ing.

The operation related to the above configuration will be explained according to the flowchart shown in FIG.

When a call arrives on the telephone line, the base unit (1) activates the incoming call detection circuit (
Current flows through the capacitor (3) of the relay (4)
) operates, and when the CPU (s) detects this (step 51), it turns on the relay (6) and closes the contact (8).
c), the line is closed (step 52). after that,
The CPU (5) performs data transmission with the transmission source communication device via the transformer (7) (step S3).

When the data transmission is completed, the CPU(s) sends a data signal, such as a binary signal (G
ool) is output to the data line (12). When the CPII (9) of the corresponding handset (8) detects this address (step S5), it turns on the relay (lO) and closes the line with its contact (lad) (step S6). Turn on the response output to the data line (12) (
Step S7). The CPU of the base unit (1) detects this, turns off the relay (6), releases the line, and ends the process (step S8゜So, the slave unit performs data transmission with the source communication device and then relays ( 11), the line is released, and the process ends (steps 510 and 511).

[Problem to be solved by the invention]

Since conventional communication devices are configured as described above, as the number of slave units (8) connected to the base unit (1) increases, the CPU
(5) Number of human outputs and data signal lines (
12), which causes the problem that the number of wires increases.

This invention was made in order to solve the problems of the conventional example as described above, and provides a communication device that can handle the connection of multiple handsets to the same telephone line without increasing the number of data signal lines. The purpose is to provide.

(Means for Solving the Problems) A communication device according to the present invention includes an incoming call detection circuit that detects an incoming call, a line closing circuit that closes a line based on the detection signal, and a communication device that connects a call originating device A. After data transmission, a base unit with a CPU that sends out an output to select a slave unit based on the transmitted data; connection circuit,
In a communication device comprising a source communication device and a plurality of slave units each having a CPU for controlling data transmission, the base unit and each slave unit share a pulse with a pulse width unique to each slave unit to be selected. A selection response input/output circuit is provided that outputs the selection signal onto the connected data signal line and detects the selection signal based on the pulse on the data signal line.

(Function) In this invention, a pulse specific to the slave unit to be selected from the CPU is given to the selection response input/output circuit of the slave unit via the selection response input/output circuit and the data signal line, and the CPU of the slave unit
A selection signal is detected by U.

〔Example〕

Hereinafter, one embodiment of the present invention will be described based on FIG. 1, in which the same parts as in FIG. 4 are denoted by the same reference numerals. In FIG. 1, the newly provided configuration is that in the base unit (1),
A transistor (L3a) whose switching is controlled based on the level of the output line (4) of the CPII (5), and a photocoupler (1) consisting of a photodiode and a phototransistor installed between the collector of this transistor and the DC power supply.
A selective response input/output circuit (13) having a
Similarly, each of the plurality of slave units (8) is also provided with a selection response input/output circuit (16) having the same configuration. The collectors and emitters of the transistors are each commonly controlled by a data signal line (19) to obtain the logical sum of the collector outputs. Furthermore, (17) and (18)
indicates the output line and input line of the CPII (9) of the slave unit (8). Each of these communication devices selects a slave unit based on the output pulse width from the CPU to the selection response input/output circuit, and each slave unit selects the slave unit based on the pulse width of the output on the data signal line from the selection response input/output circuit. It is detected by the CPU via the CPU, and data is transmitted to the source communication device.

Next, the operation of the above configuration will be explained with reference to the flowchart shown in FIG. 2 and the waveform diagram shown in FIG. 3. As in the conventional example, when a call arrives on the line, after the line is closed (steps 55 and 52), the CPU (5) connects the output line (14).
) is turned on (step S3). By this output, the transistor (t) of the selection response input/output circuit (13)
3a) is turned on, and therefore the selected responder output signal on the data f statement line (16) becomes a low level signal. After this,
The CPII (5) performs data transmission with the source communication device (step S4), and when this is completed, the following processing is performed to select a child device based on the transmitted data. Here, the handset (8
) is selected.

The CPU (5) outputs the output on the output line (14) for a certain period of time t.
1 (for example, 0.1 seconds) off f & (step 55
), it is turned on for a second fixed time h (for example, 0.1 seconds), which is the selection signal pulse width of this slave device (step S6), and then turned off. As a result, the selected responder output signal on the data signal Ps (16) is outputted as the signals shown in T2 to T4 in FIG. 3 (the logical sum of the outputs of the parent unit and each slave unit is output).
.

CPt1 (9) of the first handset (8) detects a signal change in the signal on the output input line (18) of the selection response input/output circuit (16), and detects an on pulse for 43 hours after being off for 11 hours. Then (step S7), the relay (10) is turned on to close the line, and the signal on the output line (17) is turned on (step 55. S9). As a result, the selection response input/output circuit (16) outputs a low signal. CPU of main unit (1)
(5) detects this and turns off relay (6) to open the line (step 510.5ll).

On the other hand, after transmitting data with the source communication device, the CPU (9) of the handset (8) turns off the relay (lO) to open the line and turns off the output on the output line (17) to complete the process. (Steps 512-514).

Also, to explain the process when the first handset (8) successively calls the Nth handset (not shown), the CPII (9) of the first handset (8) is the data After the transmission is completed, the output on the output line (17) is turned off for a certain period of time, and then the pulse width of the (N+1)th fixed time that becomes the address signal of the Nth slave unit N, for example, N×0.1. By outputting an on-pulse of seconds, the CPU of the Nth slave unit detects this and processes the same thereafter.

〔Effect of the invention〕

As described above, according to the present invention, a pulse having a pulse width specific to the slave unit to be selected is outputted to the base unit and each slave unit on the commonly connected data signal line, and a pulse on the data signal line is output to the base unit and each slave unit. A selective response input/output circuit is provided that detects a selective signal based on the data, so even when connecting multiple communication devices to a single telephone line, a single data signal line can be used to selectively call and respond between these communication devices. can build a system that can handle this.

[Brief explanation of drawings]

Fig. 1 is a configuration diagram according to an embodiment of the present invention, Fig. 2 is an operation flowchart of the CPIJ shown in Fig. 1, Fig. 3 is a signal waveform diagram of each part of Fig. 1, and Figs. 4 and 5 are conventional examples. FIG. 1 is a corresponding diagram of FIG. 1 and FIG. 2. In the figure, (1) is the base unit, (2) is the incoming call detection circuit, and (5)
is CPU, (6) is line closing relay, (8) is slave unit, (9) is CPII, (10) is line closing relay
(13) and (16) are selection response input/output circuits, (!9
) is the data signal line. Note that the same reference numerals in each figure indicate the same or corresponding parts.

Claims (1)

[Claims] An incoming call detection circuit that detects when an incoming call is received, a line closing circuit that closes the line based on the detection signal, and a CPU that sends out an output that selects a handset based on the transmitted data after data is transmitted with the source communication device. a base unit having a base unit, a line closing circuit that is connected to the same telephone line as the base unit and closes the line based on input of the selection signal, and a plurality of CPUs that control data transmission with the source communication device. In a communication device equipped with a slave unit, a pulse having a pulse width unique to the slave unit to be selected is outputted to the base unit and each slave unit on a commonly connected data signal line, and 1. A communication device comprising a selection response input/output circuit that detects a selection signal based on a pulse.