JP2532811B2 - Network controller - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a network control device for connecting a facsimile machine having a communication function to a circuit. A conventional network control circuit has a structure as shown in FIG. 2, a CML relay 104 is in an open state during standby, a line is a telephone set, and a subscriber telephone network incoming call detecting means 106.
And the facsimile communication network incoming call detecting means 107, respectively, but when the incoming telephone network incoming call detecting means 106 or the facsimile communication network incoming call detecting means 107 detects an incoming call from the network, the CML relay 104 is closed, The telephone set, the incoming telephone network incoming call detecting means 106, and the facsimile communication network incoming call detecting means are separated from the circuit. The block 105 of the CML relay 104 forms a direct current circuit of the line, and a hybrid coil 110 for 2-wire to 4-wire conversion is formed by AC coupling with capacitors from both ends.
And connected to the facsimile machine via In the case of automatic calling, it is necessary to prevent a collision with an incoming call. For this purpose, first the L relay 101 is closed and the photocoupler 102 is closed.
After confirming that there is no polarity reversal of the line before the incoming call for a certain period of time with the output 103, the CML relay 104 is closed and P
The relay 108 is configured to be turned on / off according to the other party's number to transmit the pulse dial signal to the network. When the transmission of all digits of the dial number is completed, the other party's response is confirmed by the polarity reversal detection circuit 109, and the CML relay 10
Facsimile communication is performed in a state where 4 is closed and the line is captured. It should be noted that the slicing device 111 is in a closed state in a normal case other than during a test or maintenance inspection. The subscriber telephone network incoming call detecting means 106 and the line are coupled by a photocoupler AC-coupled by a capacitor, and the facsimile communication network incoming call detecting means 107 and the line are coupled by a transformer AC-coupled by a capacitor. . The telephone is C-ready for calls during stand-by or control procedures when the sill is open for testing or maintenance.
When the ML relay 104 is opened, it is connected to the line. A two-wire / four-wire conversion circuit similar to the hybrid circuit 110 is also built in the telephone so that the transmitter and the receiver can be connected to the line. Such a conventional network control circuit has a CML relay for switching a signal path from a line, a relay for performing an incoming / outgoing collision prevention operation, and a dial pulse transmission. Since it has a plurality of relays such as a P relay and a plurality of coils such as a letter coil and a hybrid coil for connecting a DC circuit of a line, and a coupling coil having a high input impedance for connecting to a facsimile communication network incoming detection circuit It has a disadvantage that it cannot avoid an increase in size. That is, in more detail, about 100 mA of DC current of the line and about 4 mA
In order to withstand a DC voltage of 8V and prevent magnetic saturation and perform impedance matching, the windings of the hybrid coil and the letter coil must be made thicker, and the magnetic material must be made larger accordingly. Miniaturization is practically difficult. When connecting a two-wire balanced line with an unbalanced incoming call detection circuit, a photocoupler can be applied in a subscriber telephone network (16HZ) where the incoming call signal level is high to achieve downsizing. Facsimile communication network with low level (1300H
In Z), the photo coupler cannot be used, and the transformer coupling must be adopted, and the CML relay for signal path switching is small in size from the viewpoint of contact reliability and contact material economy. It was impossible to convert. Further, in the conventional network control circuit, even in the case of facsimile communication, the attached telephone always sounds a ringing tone for a moment when an incoming call is received from the subscriber telephone network, and unnecessary noise is generated. Become. This is because the telephone set is connected in parallel with the incoming call detection circuit during standby, and the bell sound of the telephone set rings until the time it takes to complete the incoming call detection and switch the CML relay. In addition, since it has two hybrid circuits including the inside of the telephone, it has a drawback of complicating the circuit. The present invention solves the above-mentioned disadvantages of the prior art, and has conventionally required a letter coil for closing a DC circuit, a hybrid coil for 2-wire to 4-wire conversion, and facsimile communication. The linearity of the characteristic impedance seen from the line is improved by omitting the connecting coil that connects the incoming call detection circuit of the network and the line, and various relays for switching the signal path are also omitted to make the circuit compact and high. It is an object of the present invention to provide a network control device which realizes reliability and economy and which does not cause a telephone to ring a bell when a facsimile automatic reception is started in a subscriber telephone network. That is, in the network control device according to the present invention, when a facsimile signal is detected after the call signal is detected by the incoming call detecting means, the facsimile communication is immediately started and the facsimile signal is transmitted. Is not detected within a certain time, the control unit causes the alarm sound generating unit of the facsimile apparatus to ring a ringing sound and shift to a call state. According to this technical means, by connecting the transmitter and the receiver to the time monitoring of the facsimile signal, the bell sound of the telephone is not sounded at the start of the automatic facsimile reception, and the transition to the call state is made. Even at this time, the bell sound generating section of the telephone can be used also as the alarm sound generating section of the facsimile body, so that the circuit can be downsized. A network control circuit according to an embodiment of the present invention will now be described in detail with reference to FIG. 1. Reference numeral 201 indicates a line disconnected from a facsimile machine for direct connection to a test telephone at the time of testing or maintenance. This is a divider for operation and is composed of a slide switch, but normally this test telephone is unnecessary and the divider 201 is kept closed. Reference numeral 202 denotes a rectifier circuit composed of a diode bridge, which converts the signal form from the balanced type to the unbalanced type while keeping the line polarity state constant. Reference numeral 203 denotes a transmission signal source such as a modem transmission unit, a single tone transmission unit, a telephone transmitter unit, a tone dial unit, and a voice response unit of the facsimile main body 212 via a hybrid circuit 226, an analog switch 218 and a capacitor 217 according to a control procedure. It is a multiplexer for controlling transmission to the line. Reference numerals 204 and 205 are resistors for shunting the direct current of the line to energize the light emitting diode which constitutes the photocoupler 208, 206 is a varistor for overvoltage protection, 207 is an AC signal bypass capacitor, and 209 is a constant voltage for overvoltage protection. It is a diode.
The photocoupler 208 is composed of a pair of light emitting diodes and transistors which are connected in parallel in opposite directions in order to detect the polarity reversal of the line. Reference numeral 210 is a transistor that controls a weak current that enables one of the light emitting diodes of the photocoupler 208 to be turned on without capturing a line prior to automatic calling, and 211 is a resistor that determines this current value. . The facsimile main body 212 controls the network control circuit of the present invention based on the communication procedure. 213 and 2
Reference numeral 14 denotes a transistor connected in Darlington in order to capture the line during communication and perform on / off operation of pulse dial signal transmission, and a resistor 227 determines a current value when capturing this line. Reference numeral 215 is a resistor for supplying a minute current to the gate of the field effect transistor FET216 from the line to turn it on during standby.
S (Metal Oxide Semiconductor)
The tor) type FET 216 maintains the ON state from the standby state to the end of the incoming call detection by the function of the resistor 215.
Reference numeral 217 is an AC coupling capacitor, and 218 is an analog switch circuit for controlling the opening and closing of this AC signal with the hybrid circuit 226, which is turned off and has a high impedance except during communication. Reference numeral 219 is a buffer FET for guiding the ringing signal from the network to the incoming detection means 222 by high impedance coupling which does not affect the line, 220 is a resistor for determining this high input impedance, and 221 is a capacitor for AC coupling. is there. The incoming call detecting means 222 integrates the frequency or period of the input signal to obtain 16H of the subscriber telephone network.
The z ringing signal and the 1300 Hz silent ringing signal of the facsimile network are automatically identified. 223 is the FET 219
Input resistors 224 and 225 are clamp diodes for protecting the gate input of the FET 219. Reference numeral 226 is a two-wire / four-wire conversion hybrid circuit composed of a differential amplifier and a resistor, which is coupled to the analog switch 218 with a line characteristic impedance of 600Ω. Reference numeral 227 is a resistor connected to the emitter of the transistor 214. Reference numeral 228 is a demultiplexer for selecting and guiding the reception signal from the hybrid circuit 226 to the reception circuit of the modem reception unit, the single tone detection unit or the telephone reception unit of the facsimile main body 212 according to the control procedure. Next, the operation of the network control circuit configured as described above will be described. FET21 in the standby state
Only 6 is on, and the line is connected to the incoming call detecting means 222 only. At the time of automatic dialing, the FET 216 is turned off and the transistor 210 is turned on for about 300 milliseconds (hereinafter referred to as T ₁ ), and during this period, the photocoupler 208 detects the presence or absence of polarity reversal to prevent the collision of incoming and outgoing calls. When the photocoupler 208 detects polarity inversion during T _1, an incoming signal is sent from the network, so that the transistor 210 is turned off and the FET 216 is turned on.
After detecting the incoming call by the incoming call detecting means 222, the FET 216
Is turned off and the transistors 213 and 214 and the analog switch 218 are turned on to form a direct current circuit, and an alternating current signal is introduced to the facsimile main body 212 via the hybrid circuit 226, the multiplexer 203 or the demultiplexer 228 to make the facsimile communicable.
The automatic incoming call operation from the standby state is performed in exactly the same manner as the above except that the outgoing / incoming call collision prevention operation before the automatic outgoing call is not performed. When the polarity inversion is not detected within the ON state T ₁ period of the transistor 210, the transistors 213 and 214 are ON / OFF controlled according to the dial number while the transistor 210 is OFF, and the dial pulse is sent to the network. . When tone dialing is performed without using pulse dialing, the transistors 213 and 214 are turned on, and a dial signal is sent from the tone dial section of the facsimile main body 212 to the network via the multiplexor 203 and the hybrid circuit 226. When all digits have been dialed in this way, transistors 213 and 2
14 is turned on, and after confirming the connection response by the polarity inversion by the photo coupler 208, the analog switch 218
Is turned on to form a signal path for facsimile communication via the hybrid circuit 226. When the photocoupler 208 does not detect the polarity reversal as a connection response confirmation from the network at the end of dialing, or when the interruption instruction from the network is detected as the polarity reversal during the facsimile communication, the facsimile stands by. Return to the state. During a telephone call, the transmitter of the telephone of the facsimile main body 212 is connected to the hybrid circuit 226 via the multiplexer 203 and the receiver to the demultiplexer 228. In this call state, the signal path is formed by the operation button instruction of the facsimile main body 212 or the incoming call detection means 222 detects the incoming call from the subscriber telephone network, and the single tone part, the voice response part and the modem of the facsimile main body 212 are detected. This is the case when a facsimile signal is not detected within a certain time after responding at the receiving unit.
At this time, the telephone rings the bell for the first time. The semiconductor switch circuit or analog switch in the network control circuit according to the present invention is not limited to the structure of the embodiment shown in FIG. You may comprise. The switching element may be a FET or bipolar transistor, and a thyristor may be used. As described in detail above, according to the present invention, the bell sound generating section of the telephone is also used as the alarm sound generating section of the facsimile main body to further reduce the size and cost of the circuit. In addition, the time monitoring of the facsimile signal has the effect of contributing to noise prevention because the telephone is configured not to generate a ringing tone even when receiving a call from the subscriber telephone network during facsimile communication.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of a network control circuit according to an embodiment of the present invention. FIG. 2 is a block diagram showing a conventional network control circuit. Reference numeral 201 slide switch 202 rectifier circuit 203 multiplexer 216, 219 FET 206 Varistor 208 Photocoupler 209 Constant voltage diode 218 Analog switch 212 Facsimile body 222 Incoming call detecting means 223, 225 Clamp diode 226 Hybrid circuit 228 Demultiplexer

   ────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Takahiro Kikuchi               Matsu, 2-3-8 Shimomeguro, Meguro-ku, Tokyo               Shimoden Co., Ltd. (72) Inventor Toshio Narushima               Matsu, 2-3-8 Shimomeguro, Meguro-ku, Tokyo               Shimoden Co., Ltd. (72) Inventor Hiroaki Nouchi               Matsu, 2-3-8 Shimomeguro, Meguro-ku, Tokyo               Shimoden Co., Ltd.                (56) References JP-A-61-127258 (JP, A)

Claims (1)

(57) [Claims] A network control device for connecting a facsimile apparatus having an automatic reception function to a line, comprising polarity inversion detection means for detecting polarity inversion of the line, and a polarity inversion detection means for detecting the polarity inversion of the line. Based on the detection, an incoming call detecting means for detecting an incoming call signal from the line network, and when a facsimile signal is detected after the incoming call detecting means detects the calling signal, the facsimile communication is immediately started and the facsimile signal is transmitted. A network control device comprising: a control unit that causes a warning sound generation unit of the facsimile device to ring a ringing tone and shift to a talking state when the detection is not made within a predetermined time.