JPS63209264A - Line switching circuit for modem - Google Patents

Abstract

PURPOSE:To prevent an erroneous disconnection by an auxiliary power source supplying part to supply a power source to a calling function part when a communication function part is connected to an exchange line. CONSTITUTION:An exchange line 5 is connected to either of a communication function part 2 and a calling function part 1 by a relay 11 of a switching means 4. At this time, when the exchange line 5 is connected to the communication function part 2, an auxiliary power source supplying part 3 is connected through an interlocking switch 12 to the communication function part 1, the power source is supplied and the calling function part 1 is made into an operatable condition. When the exchange line 5 is switched from the condition to the calling function part 1, the auxiliary power source supplying part 3 is separated from the calling function part 1, the power source supply is stopped, and simultaneously, the switching means 4 is operated and the exchange line 5 is connected to the calling function part 1. Thus, when the line connection is switched from the communication part to the calling function part, the calling function part is made into an operating state immediately and the line connecting condition car be held.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a line switching circuit for a modem and modem for switched lines equipped with a communication function, and more particularly to a line switching circuit for a modem and a modem that switches between a communication function and a voice function.

[Prior Art] Conventionally, the line switching circuit of this type of modulation/demodulation device is generally configured with a switching means having a relay or the like in order to switch between the communication function section and the call function section. When connected, the call function section was in an open state. Figure 2 shows its configuration. In the figure, reference numeral 6 denotes a communication function unit for making a telephone call, and 7 a communication function unit for performing data communication. and is connected to the exchange line 9. In this manner, when the switched line 9 and the communication function section 7 are connected, the other communication function section 6 is in an open state.

[Problems to be Solved] Regarding the line switching circuit of the above-mentioned conventional modem device, if the telephone function section 6 is constituted by an integrated circuit,
When switching the exchange line from the communication function section 7 to the call function section 6, the call function section 6 has been open until then and is not supplied with power, so that the function cannot be started at the same time as the switching. Therefore, charging time is required before operation becomes possible, and there is a drawback that the exchange line 9 may be accidentally disconnected during this time.

[Means for Solving Problems] The present invention has been made to solve the above-mentioned problems of the conventional art. In a line switching circuit of a modem and modem equipped with a communication function section and switching means for connecting either the communication function section or the communication function section to a switched line, only when the communication function section is connected to the switched line. The present invention provides a line switching circuit for a modem and modem device, characterized in that it is equipped with an auxiliary power supply section for supplying power to a communication function section.

[Examples] Examples of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing a line switching circuit of a modulation/demodulation device according to an embodiment of the present invention.

The line switching circuit of the modem of this embodiment has a call function section 1 for making calls, a communication function section 2 for making data communications, and one of these call function section 1 or communication function section 2 is replaced. It has a switching means equipped with a relay 11 that is connected to the line 5, and an auxiliary power supply section 3 for supplying power to the communication function section 1 only when the exchange line 5 is connected to the communication function section 2. are doing. In addition, the auxiliary power supply section 3
An interlocking switch 12 is connected to the relay 11 and closes when the call function unit 3 side is open to supply power to the call function unit 3.
has been established.

Next, the operation will be explained.

First, the switched line 5 is connected to either the communication function section 2 or the telephone function section 1 by the relay 11 of the switching means 4. At this time, when the switched line 5 is connected to the communication function unit 2, the auxiliary power supply unit 3 is connected to the call function unit 1 via the interlocking switch 12, supplies power, and makes the call function unit 1 operational. .

Next, when switching the switched line 5 to the call function section 1 from this state, the auxiliary power supply section 3 is disconnected from the call function section 1, the power supply is stopped, and at the same time, the switching means 4 is activated to switch the switched line 5 to the call function section 1. Connect to functional unit 1.

[Effects of the Invention] As explained above, according to the present invention, when the line connection is switched from the communication function section to the call function section, conventionally it takes time for the call function section to become operational. During this time, the line was accidentally disconnected, but by supplying power to the call function section only when the communication function section is selected and leaving it in an operational state, the line connection can be switched from the communication function section to the call function section. When this occurs, the telephone call function section immediately enters the operating state, the line connection state can be maintained, and erroneous disconnection can be prevented.

Another advantage is that when the communication function section is selected, the on/off state of the handset connected to the call function section can be monitored.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the present invention, and FIG. 2 is a block diagram of a conventional line switching circuit.

Claims (1)

[Claims] A modulation/demodulation device comprising a call function section for making calls, a communication function section for data communication, and a switching means for connecting either the call function section or the communication function section to a switched line. 1. A line switching circuit for a modem device, characterized in that the line switching circuit includes an auxiliary power supply section for supplying power to a communication function section only when the communication function section is connected to a switched line.