JPH03198499A - Communication terminal equipment with automatic response function - Google Patents

Abstract

PURPOSE:To prevent MODEM communication from being erroneously established by monitoring a silent state for fixed time and permitting the MODEM communication in the silent state continued for fixed time when a start code for MODEM communication is received. CONSTITUTION:When an incoming call arrives from a telephone line through a line terminal L, a CPU 12 receives the incoming call signal detected by an incoming call detecting circuit 9, operates a relay contract rl1, closes a direct current loop and automatically responds to this incoming call. When receiving the start code for MODEM communication out of the received signal, the silent state is monitored for the fixed time and when the silent state is continued for the fixed time, the start code is decided as normal. Then, the MODEM communication is permitted and established. Thus, the start code for MODEM communication can correctly be received and the exact MODEM communication can be executed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a communication terminal device with an automatic response function that performs modem communication using a received signal after receiving an outside line call.

[Prior Art] Some conventional communication terminal devices with an automatic answering function receive an identification signal sent from the other party's telephone after automatically answering an incoming external call, and perform operations according to this identification code. . In other words, the telecontrol mode and V
The system identifies a modem communication mode using an ENQ signal as a start code, such as a V.23 modem, and performs operations according to these start codes, that is, telecontrol and modem communication.

[Problems to be Solved by the Invention] In the above-mentioned conventional communication terminal device with an automatic response function, in the case of telecontrol mode, a start code is transmitted from the other party's telephone using a PB double signal;
Since the doubled signal is superimposed on surrounding noise and voices, it is often mistakenly received as the ENQ signal, which is the start code for modem communication. In such cases, it is determined that there is a modem communication error and malfunctions occur, such as the line being disconnected.

[Means for Solving the Problems] In order to solve such problems, a communication terminal device with an automatic response function according to the present invention starts by receiving a start code for modem communication and maintains AC for a certain period of time while the timer is operating.
The device is equipped with a timer means for waiting for the return of the K signal, and a monitoring means for monitoring silence during a certain period of time and permitting modem communication based on the monitoring result.

[Operation] When a start code for modem communication is received, a silent state is monitored for a fixed period of time, and if there is no sound for a fixed period of time, modem communication is permitted.

[Example] Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of a communication terminal device with an automatic response function according to the present invention. In the figure, 1 is a line sending signal selection circuit, and 2 is an AT T that performs signal attenuation.
, 3 is a data selection circuit, 4 is an FSK communication circuit that performs modem communication, 5 is a receiving amplifier circuit, 6 is a DTMF receiving circuit that receives the PB multiple signal, and 7 is a DT that sends the PB multiple signal to the line.
MF sending circuit 8 is a dial pulse circuit that sends a dial pulse signal to the line. Further, 9 is an incoming call detection circuit, 10 is a current detection circuit, 11 is a line disconnection detection circuit, 12 is a CPU that controls this device, 13 is a ROM, and 14 is an R
AM and L are line terminals connected to a telephone line, T is a terminal to which a telephone is connected, rρ1 and rβ2 are relay contacts for connecting a DC loop, etc., and TR is a transformer.

When an incoming call arrives from the telephone line via the line terminal, the CPU 12 receives the incoming signal detected by the incoming call detection circuit 9, activates the relay contact r11, connects the DC loop, and automatically responds to this incoming call. respond. After that, the PB double signal from the line or the modem communication start code (EN
Q signal) to the DTM F receiving circuit 6 or F
It receives via the SK communication circuit 4 and performs telecontrol processing or modem communication.

Next, the detailed operation of the communication terminal device with automatic response function of the present invention will be explained based on the flowchart of FIG.

When an incoming call from the line is automatically answered, a voice signal is outputted to the line by a voice synthesis circuit (not shown) in step 50 and is heard by the other party. Subsequently, in step 51, a carry is sent out on the line for 5 seconds. Thereafter, in step 52, it is determined whether a start code for telecontrol is received by the DTMF signal, that is, the PB double signal from the other party via the DTMF receiving circuit 6, and when this is rNJ, the Stellar 153 receives the FSK ENQ signal, i.e. F.S.
It is determined whether a start code for modem communication is received from the other party via the K communication circuit 4.

When “N” in step 53 and step 52
When the result is "Y" in step 54, the result is "D" again in step 54.
If the reception of the TMF signal is determined to be "Yl", that is, if the start code for telecontrol can be received, telecontrol processing is performed in step 55.
After that, the line is released at Stella 156 and the process ends. If "N" in step 54, that is, if the start code for telecontrol cannot be received, step 57
At step 58, the 30-second timer started after the carry is sent out is timed up and updated, and at step 58 it is determined whether or not this timer has timed out. And this is "
If the answer is "N", the process returns to step 52 and the reception of the DTMF signal is determined again, and if the answer is "Y", that is, 30 seconds have elapsed, the line is released in step 56.

If "Y" is determined in step 53, that is, if the start code for modem communication can be received, a two-second timer is started at this time, and it is determined in step 60 whether or not this two-second timer has timed out. If this is ``N'', reception of the DTMF signal is determined in step 61, and if ``N'', the process returns to step 6o, but if this is ``Y'', telecontrol processing is performed in step 55.

If the result in step 60 is "Y", that is, the two-second timer times out, it is determined in step 62 whether or not there have been five or more characters received within the two seconds. Return to That is, at this time, it is determined that the start code for modem communication could not be received normally due to the noise condition, and the process returns to step 52 to again determine whether the start code has been received.

Next, when the result in step 62 is "N", that is, when the number of received characters is 5 or less, in step 63, a response signal corresponding to the start code of the other party, that is, an ACK signal, is sent to the FSK communication circuit 4. is sent to the other party via the , and modem communication is permitted. Subsequently, in step 64, FSK processing, that is, modem communication processing is performed.

Then, in step 65, it is determined whether or not there have been 11 or more text errors during modem communication processing, and "
If the answer is "N", it means that there has been no text error, and the line is opened in step 68 to normally terminate the modem communication process.

Next, if the result in step 65 is "Y", that is, if there is a text error at least once, it means that the modem communication has failed, and in step 66, a try counter, that is, a counter for retrying modem communication, is set. It is incremented (added), and then in step 67 it is determined whether this count value has become -E five times or more, and this is "
If the answer is "N", the process returns to step 52 and the start code is received again. If the answer is "Y", that is, if the value of the try counter reaches 5 times or more, the noise condition is so severe that modem communication is impossible. Step 6
Press 8 to open the line and exit.

As explained above, in the present invention, after the other party, that is, the center device transmits a modem communication start code to the terminal device, it waits in silence for a certain period of time in order to receive an ACK signal from the terminal device. Focusing on this, this communication terminal device with an automatic response function monitors the silence state when it receives a modem communication start code from the received signal, and determines that it is a normal start code if it continues for a certain period of time. modem communication is established by permitting modem communication. Also, even after modem communication has been established, if modem communication cannot be performed normally. ! If the sound condition does not continue, it is determined that the sound signal is mixed in or ambient noise is detected, and the start code is detected again.

[Effects of the Invention] As is clear from the above explanation, the communication terminal device with automatic answering function according to the present invention, after automatically answering an incoming external call,
When the start code for modem communication is received, the system monitors for a period of silence, and if there is no sound for a certain period of time, modem communication is permitted. This has the effect of allowing communication.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing one embodiment of a communication terminal device with an automatic response function according to the present invention, and FIG. 2 is a flowchart explaining this operation. 1...Line transmission signal selection circuit, 3...Data selection circuit, 4...FSK communication circuit, 5...Reception amplifier circuit, 6...DTMF reception circuit, 7...・・D
TMF sending circuit, 8...Dial pulse circuit, 9.
...Incoming call detection circuit, 11 is a line disconnection detection circuit, 12...
...cPU, 13...ROM, 14...RAM
.

Claims (1)

[Scope of Claims] A communication terminal device with an automatic response function that automatically responds to an incoming external call, receives a start code for modem communication, and then returns an ACK signal to perform modem communication, which starts upon reception of the start code for modem communication. and a timer means for waiting for the return of the ACK signal for a certain period of time while the timer is operating, and a monitoring means for monitoring a silent state during the certain period of time and permitting modem communication based on the monitoring result. Communication terminal equipment.