JPH0259676B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for adding a standard telephone to a button telephone device, and more specifically, by mounting an extension board on which a button telephone interface circuit is mounted to a predetermined board position of a main device, a pair of communication lines can be connected. The present invention relates to a method for adding a standard telephone to a button telephone device in which a button telephone connected by a pair of signal lines is added. Generally, when a key telephone is installed in a remote location from the main device, a simple data transmission method becomes impossible due to data attenuation due to the maximum line and data delay due to distributed capacity, so a two-wire connection using a pair of communication lines is standard. A telephone was required to be installed. The two-wire connection long-distance telephone equipped with this type of conventional button telephone device has two main devices:
It had an external dedicated control circuit. However, such a button telephone device requires a dedicated control circuit inside and outside the main device, making the structure complicated and disadvantageous in that it is not economical. In view of the above points, the present invention has been made to solve such problems and eliminate such drawbacks.The purpose of the present invention is to replace the telephone control unit in the main unit, thereby making it possible to control one extension line. To provide a method for adding a standard telephone to a button telephone device which can be used as a four-wire connection button telephone or a two-wire connection standard telephone and is advantageous in terms of mounting space. In order to achieve these objects, the present invention provides loop current supply means, hook state detection means, ringing signal generation means for generating a ringing signal in response to an incoming call control signal, and ringing signal generation means for generating a ringing signal in response to an incoming call control signal. A standard telephone interface circuit comprising a line switching means for connecting the generating means, a board identification signal generating means for generating a board identification signal indicating that the circuit is for a standard telephone, and a terminal for incoming call control signals;
The terminal for the line switching means and the terminal for board identification are assigned as different terminals from the terminals for the button telephone interface circuit, and embodiments of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a block diagram showing the basic configuration of an embodiment of a key telephone device to which the standard telephone extension method according to the present invention is applied. In the figure, KSU indicates the main device side, and ST indicates the terminal side. La, Lb are office line terminals connected to the office line, E is the ground terminal of the telephone line, PS is a commercial power supply AC, for example, a power supply that receives AC 240V and obtains DC (+) 24V and DC (+) 5V, TSD is an incoming signal detection circuit unit connected to the office line terminal La via a capacitor and connected to the office line terminal Lb, and detects incoming signals from the office line terminals La and Lb. FA and FB are relays for switching _and connecting _{the terminal} to _the central telephone line or extension telephone line;
Relay contact for switching extension lines, H is the relay that operates to hold the central office line, h is the holding contact, RC
is a relay that operates only for about 500ms when a re-transmission operation is performed, rc is a contact for that PBX,
RDC is a relay drive circuit that drives these relays FA, FB, H, and RC based on control signals from the control circuit CPU, and HSG is connected to the station line terminal La and connected to the station via the hold contact h. This is a hold music signal generation circuit section connected to line terminal Lb. ICC is an individual call control circuit unit that sends and receives individual call information to and from the control circuit CPU, and DPC is an intercom control circuit unit that sends and receives door phone information to and from the control circuit CPU. Circuit section DPC is door phone terminal DPT
It is configured to transmit and receive intercom information between the door phone and the door phone, and to send and control a necessary control signal to the door unlocking mechanism DAL. FNS is a function setting section that sets various functions as a button telephone device between the control circuit section CPU, and OSC is a tone signal generation circuit section that generates ringing signals and alarm signals. Generates a ring signal when receiving a call or an extension call, and the ring signal changes from 500/600Hz to 16Hz
This call signal and 600Hz alarm signal are modulated by the switch circuit AS, whose on/off is controlled by the control signal from the control circuit CPU.
The signal is input to the amplifier circuit unit AMP via the AMP circuit and is amplified. T is a terminal control interface circuit section (hereinafter referred to as "interface circuit section") that connects four wires via contact points fa ₁ , fb ₁ , ... for switching the office line/extension line, and contacts fa ₂ , fb ₂ ... for switching the office line/extension line. (abbreviated as) IF ₁ , IF ₂ ...IF ₅ b, respectively, and the door phone control circuit.
The transformer T is connected to the DPC and the amplifier circuit section AMP, and together with the resistor and capacitor connected to its winding, the transformer T constitutes an extension current supply circuit. The CVD is a control voltage detection circuit unit that sends and receives necessary control information to and from the control circuit unit CPU, and also detects control voltages from the interface circuit units IF ₁ , IF ₂ , . . . IF ₅ b. And the interface circuit section shown by the solid line
4-wire button telephones (hereinafter referred to as button telephones) that transmit and receive signals and voice between IF ₁ and IF ₂ , respectively.TEL ₁ and TEL ₂ are for fixed use.
In addition, the interface circuit section IF ₃ shown by the broken line,
IF ₄ , IF ₅ a and key telephone TEL ₃ , TEL ₄ ,
TEL ₅ a is for expansion. Note that the interface circuit section IF ₅ a and the key telephone TEL ₅ a can be changed to an interface circuit section IF ₅ b with a two-wire connection and a terminal telephone (standard telephone) TEL ₅ b with a two-wire connection. and,
Each interface circuit section for this expansion IF ₃ to _{IF 5} a
When (IF ₅ b) is mounted as a fixed device, it goes without saying that it is connected via the office line/extension line switching contacts fa and fb in the same way as the interface circuit units IF ₁ and IF ₂ . Then, _{the office line/extension line switching contacts fa 1 , fb 1 and contacts fa 2} ,
The office line side of fb ₂ is connected to the office line terminals La and Lb, respectively. In addition, the interface circuit section IF ₁ ~
The IF ₅ a (IF ₅ b) is configured to be supplied with a control signal from the control circuit CPU. This standard telephone TEL ₅ b with two-wire connection performs inter-extension calls and central office line calls with other key telephones TEL ₁ to TEL ₄ , and also makes and receives calls from central office lines and extensions, and communicates with other key telephones TEL ₁ to TEL 4. It is configured to allow central line call transfer from TEL ₄ . FIGS. 2 and 3 are configuration diagrams for explaining the method for adding standard telephones in the button telephone device according to the present invention. FIG. 2 shows an example in which there is one central office line and five extension terminals. FIG. 3 shows extracted portions of the control unit of the key telephone and standard telephone in FIG. 2. In order to facilitate understanding of the present invention, this will be explained first. In this Figure 2, the same numbers as in Figure 1 indicate corresponding parts, L is the telephone line (office line) connected to the office line terminals La and Lb, and CU ₁ , CU ₂ , ... CU ₅ a are the main lines. _The key telephone control units _{TEL 1 ,} TEL ₂ , . CU ₅ b shown in Fig. 2b is a standard telephone control unit installed in the main unit KSU, and TEL ₅ b is a standard telephone with a two-wire connection of an extension connected to this standard telephone control unit CU ₅ b. be. In FIG. 3, a shows the side of the button telephone control units CU ₁ to CU ₅ a, and b shows the side of the standard telephone control unit CU ₅ b.
In Fig. 3a, f ₁ and f ₂ are contact points L for switching between the office line and the extension line of relay F (see Fig. 5 described later) for switching and connecting the terminal to the office line communication line or extension line communication line. is a loop monitoring relay that monitors the loop of the communication line, and CPU is the control circuit section. In Fig. 3b, the same numbers as in Fig. 3a indicate corresponding parts, and fe ₁ and fe ₂ are relays for switching and connecting the terminal to the central office line communication line or extension line communication line.
Contacts i ₁ and i ₂ for switching the office line/extension line of the FE (see Figure 6 described later) are relays I that operate when sending a ringing signal and a busy tone signal to the standard telephone TEL ₅ b.
LE is a loop monitoring relay that monitors the loop of the communication line, and IT/IS is an extension communication current supply circuit that supplies communication current to the extension. IS corresponds to transformer T shown in FIG. RGO and BTG are a calling signal generating circuit section and a busy tone signal generating circuit shown in FIG. 6, which will be described later. FIG. 4 is a block diagram showing a specific structure of an embodiment of the present invention, and shows only the parts necessary for explanation. In FIG. 4, the same parts as in FIG. 1 are given the same reference numerals, and their explanation will be omitted. LC is the station line terminal
This is a central office line circuit connected to the central office line (telephone line) via La and Lb.This central office line circuit LC is the central office line communication line EX/
The hold signal is connected to the PH and includes the incoming signal detection circuit TSD, PBX retransmission unit, arrester, etc. shown in Figure 1, and includes the hold tone signal generation circuit HSG shown in Figure 1 for station line hold. It is configured so that the circuit HC can be connected. Then, the central office line communication line connected to this central office line circuit LC
EX and PH are the contacts of relays FA and FB shown in Figure 1.
It is connected to the installed button telephones TEL ₁ and TEL ₂ via fa ₁ , fa ₂ , fb ₁ and fb ₂ respectively, and also connects to the 4-wire connection button telephone TEL ₃ which is an expansion board and 4-wire connection or 2-wire connection. Connection terminal phone TEL ₅
It is connected to the. One end of the relays FA, FB...H, and RC is connected in common, and this common connection point is connected to a (+) 24V power supply, and the other ends of each of the relays FA, FB...H, and RC are connected to the control circuit section CPU. decoder connected to
They are connected to ports Q0, Q1...Q5, and Q7 of IFC ₁ , respectively. In addition, ports Q0 and Q1 of the decoder IFC ₂ connected to the control circuit CPU are connected to the mounted button telephones TEL ₁ and TEL ₂ , and ports Q2 and Q4 of the decoder IFC ₂ are connected to the button telephone TEL ₃ and buttons on the expansion board. Connected to each terminal 10 of the terminal telephone TEL ₅ consisting of a telephone or standard telephone, port Q5 of the decoder IFC ₂
are connected to button telephones TEL ₁ to TEL ₃ ... and terminal 8 of terminal telephone TEL ₅ with 4-wire connection or 2-wire connection, and ports Q6 and Q7 of decoder IFC ₂ are connected to terminals 1 and 2 of terminal telephone TEL ₅ , respectively. has been done. Further, the port Q0 of the decoder IFC ₃ connected to the control circuit CPU is connected to the terminal 3 of the terminal telephone TEL ₅ . Then, output port 0 of the control circuit CPU,
R1 is a button telephone via an inverter.
Connected to TEL ₁ and TEL ₂ , and also control circuit section
The output ports ₂ and ₄ of the CPU are respectively connected to a terminal 14 of a button telephone TEL ₃ and a terminal 14 of a terminal telephone TEL ₅ via an inverter. In addition, the input port 2 of the control circuit CPU is the terminal 1 of the button telephone TEL ₃ ... and the terminal telephone TEL ₅ .
The input port 11 of the control circuit CPU is connected to the terminal 6 of the terminal telephone TEL ₅ . Terminal 5 of this terminal telephone TEL ₅ is connected to the extension control circuit ICB. In addition, terminal 9 of the button telephone TEL ₃ and terminal 9 of the terminal telephone TEL ₅ are each connected to a relay drive circuit.
Connected to the RDC output terminal. In addition,
The output end of this relay drive circuit RDC is connected to a terminal 9 of a button telephone TEL ₄ (not shown). Then, the contacts of relays FA and FB (see Figure 1)
For fa ₁ , fa ₂ , fb ₁ , fb ₂ , the corresponding terminal is connected to the extension line IT/PH at the dotted line contact position, and the corresponding terminal is connected to the central line communication path EX at the solid line contact position.・Configured to be connected to PH. When each of these relays FA, FB... is energized, its contacts fa ₁ , fa ₂ , fb ₁ , fb ₂ ... operate and assume the positions indicated by the dotted lines. For example, a button telephone
To make a central line call, TEL ₂ goes off-hook and presses the line button (not shown), which activates the relay.
FB has been restored, and its contacts fb ₁ and fb ₂ are at the contact positions shown by solid lines, so that the button telephone TEL ₂ is configured to be connected to the central office line EX/PH. You can also use this button phone
The relay FB is re-energized by the on-hook or hold operation of TEL ₂ , and its contacts fb ₁ and fb ₂ are configured to take the operating position shown by the dotted line. Here, the terminals 1, 2, 3, 5 and 6 on the terminal telephone TEL ₅ , which is the expansion board, are terminals exclusively for standard telephones with two-wire connection, and the terminals 8, 10, 11, 12, which do not have parentheses, Terminals 17 and 18 are dedicated terminals for a four-wire button telephone.
And 1, 2, 4 to 7, 9, which do not have (),
Terminals 13, 15, and 17 are common terminals for two-wire and four-wire terminal telephones. T is a transformer constituting the extension communication current supply circuit, and this transformer T corresponds to the transformer T shown in FIG. The next winding S is the tone signal generation circuit section
Connected to the OSC amplifier circuit section. Then, the extension control circuit ICB receives the dial pulse DP ₁ from the 4-wire terminal interface circuit and the 2-wire terminal interface circuit, that is, from the terminal telephone
It is configured to count the dial pulses DP ₂ from the terminal 5 of the TEL ₅ and send the counting information to the control circuit CPU. 5 and 6 are circuit diagrams showing specific configurations of a four-wire connection button telephone and a two-wire connection standard telephone mounted on the terminal expansion board in the embodiment shown in FIG. 4. FIG. . In this figure 5, F is the terminal 1 to which the power supply (+) 24V is applied and the relay drive circuit shown in figure 4.
A relay is interposed between the terminal 9 connected to DC and is used to switch and connect the terminal to the office line communication line or extension line communication line; f ₁ and f ₂ are relay contacts for switching between the office line and extension line; is inserted into the communication line loop for loop monitoring, and is connected in series to this relay contact _f1 , and operates when the terminal telephone is off-hooked and a DC loop is created. l is the loop monitoring contact. Its one end is connected to terminal 13, and the other end is connected via diode D to the collector of transistor Q, which is turned on by signal DBO from output port 4 of control circuit CPU shown in FIG. ing. And the above relay contact
The normally closed contacts of f ₁ and f ₂ are connected to the office line communication lines EX and PH via terminals 6 and 7, respectively, and the normally open contacts are connected to the internal line communication lines IT and PH via terminals 4 and 5, respectively. ing. Here, contacts f ₁ , f ₂ and relay L of relay F correspond to contacts f ₁ , f ₂ and relay L shown in FIG. 3a, respectively. Terminals 8, 10 to 12, 17, and 18 in this four-wire connection button telephone are dedicated terminals for the button telephone, and terminals 1, 2, 4 to 7,
Terminals 9, 14, 15, and 16 are common to standard telephones with two-wire connections. Note that CH is a chiyoke coil. At the dotted line positions of contacts f ₁ and f ₂ of relay F, the terminal is connected to the extension line IT/PH, and at the solid line position, the terminal is connected to the central office line EX/PH. has been done. This relay F
When energized, its contacts f ₁ and f ₂ operate and assume the positions indicated by the dotted lines. For example, when key telephone TEL ₅ a goes off-hook to make a central line call and presses the line button (not shown), relay F is restored and its contacts f ₁ and f ₂ are the contacts shown in solid lines. The button telephone TEL ₅ a is configured to be connected to the central office line EX/PH. You can also turn on/off this button phone TEL _5A .
The relay F is re-energized by a hook or hold operation, and its contacts f ₁ and f ₂ take the operating position shown by the dotted line. In Figure 6, FE is the power supply (+) 24V and the fourth
Relays fe ₁ , fe ₂ are interposed between the terminal 9 connected to the relay drive circuit RDC shown in the figure and are used to switch and connect the terminal to the central office line communication line or extension line communication line.
is a relay contact for switching between the office line and extension line, and its normally closed contact connects to the office line communication path via terminals 6 and 7, respectively.
The normally open contacts are connected to the extension lines IT and PH via terminals 4 and 5, respectively. LE is a loop monitoring relay that operates when the terminal telephone is off-hook and a DC loop is formed, and one end of it is connected to the central office line via contact _i1 of relay I.
It is connected to a relay contact fe ₁ for switching extensions, and the other end is connected via a terminal 15 to a standard telephone TEL ₅ b with a two-wire connection, which is a terminal telephone. Further, the relay contact fe ₂ for switching between the office line and the extension line is connected via the contact i ₂ of the relay I and the terminal 16 to a standard telephone TEL ₅ b having a two-wire connection. Reference numeral T ₁ is a chiyoke coil constituting an extension current supply circuit, and this chiyoke coil T ₁ corresponds to the transformer T shown in FIGS. 1 and 4. In addition, the contacts fe ₁ and fe ₂ of the above relay FE and the relay
Contacts i ₁ , i ₂ of LE and relay I are contacts fe ₁ , fe ₂ and relay LE and contacts i ₁ , fe 2 shown in FIG. 3b, respectively.
Corresponds to i ₂ . RGO is a ringing signal generation circuit whose output terminals are connected to both ends of the primary winding P of the transformer T ₂ via resistors R ₁ and R ₂ and Darlington-connected transistors Q ₁ and Q ₂ , respectively. . BTG is a busy tone signal generation circuit, and its output terminal is connected to the contact bu of the relay BU via a resistor R ₃ and a capacitor C ₁ in series. PC is a photocoupler consisting of a light emitting element Pd and a light receiving element Pt, and this photocoupler PC is connected in a DC loop when sending out a calling signal. The anode side of the light emitting element Pd is connected via a resistor R ₄ to a terminal 1 to which a power (+) 24V is applied, and the cathode side is connected via a diode D ₁ to a contact bu of a relay BU to receive light. The collector of element Pt is connected via resistor _R5 to terminal 1 to which power (+) 24V is applied and terminal 2 connected to signal ground SG.
The interface circuit shown in FIG _. 4 is connected to the base of a transistor _Q5 which _{is connected in series with resistors R6 and R7 between} the
It is connected to the terminal 3 to which the control signal RSTN is applied from the port Q0 of IFC ₃ , and the emitter of the photodetector Pt is connected to the base via the resistor _R9 .
It is connected to terminal 2, which is connected to signal ground SG. Also, a transistor Q ₆ whose emitter is connected to terminal 1 to which the power supply (+) 24V is applied
The collector of is connected to the midpoint tap of the primary winding P of the transformer T ₂ via a resistor R ₁₀ , and the base is connected to the connection point of the resistors R ₆ and R ₇ . and,
These constitute a calling signal control circuit. In addition, a capacitor C ₂ is connected in parallel to the secondary winding S of this transformer T ₂ , and one end of the secondary winding S is connected to the terminal 2 connected to the signal ground SG.
The other end is connected to the contact bu of the relay BU through the capacitor _C3 . On the other hand, one end of relay I, which operates when sending a ringing signal and a busy tone signal to standard telephone TEL ₅ b, and one end of relay BU, which operates when sending a busy tone to standard telephone TEL ₅ b, are each connected to the power supply (+) 24V. The other ends are grounded via transistors Q ₇ and Q ₈ , respectively. and,
The bases of these transistors Q ₇ and Q ₈ are connected to the decoder IFC ₂ shown in FIG. 4 via resistors R ₁₁ and R ₁₂ , respectively.
Terminal 1 is applied with the control signal IDV from port Q6 of the decoder IFC 2, and terminal ₂ is applied with the control signal BUDV from port Q7 of the decoder IFC 2 shown in FIG.
It is connected to the. One end of the contact le of the relay LE is connected to the terminal 13 connected to the input port 2 of the control circuit CPU shown in FIG. 4, and the other end is connected to the diode _D2.
is connected to the output port 4 of the control circuit CPU shown in FIG. 4 through the inverter INV and the inverter INV in series,
The connection point between the inverter INV and the diode _D2 is connected to the terminal 14 through the diode _D3 .
Input port 1 of the control circuit CPU shown in Figure 4
The input terminal of the inverter INV is grounded via a resistor _R15 . Here, the contact le of the relay LE is configured to give hook information to the control circuit CPU shown in FIG. Next, the operation of the embodiment shown in FIG. 4 will be explained with reference to FIGS. 5 and 6. First, the terminal phone
Standard telephone with 2-wire connection mounted on TEL ₅ board
TEL ₅ b and 4-wire connection button telephone TEL ₁ , TEL ₂ ,
TEL ₃ When communicating with
When the telephone is turned off and the other party's key telephone is called, and the other party answers, the communication is carried out via the extension communication line IT/PH using the current supplied to the extension communication line IT/PH. Next, in the case of simultaneous ringing, for example, when a four-wire connected key telephone TEL ₂ is off-hook and a simultaneous ringing is performed by speaking from the handset while holding down the extension button, the key telephone
From the telephone circuit of TEL ₂ through the telephone line to the extension telephone line
Pass through IT/PH and use each button telephone TEL ₁ , TEL ₂ ...
given to the speakers. On the other hand, the ringing signal from the tone signal generation circuit section OSC that generates the ringing signal and the alarm signal is
Turns on and off by a control signal from the control circuit CPU applied to the gate of the switch circuit AS shown in the figure.
Off control is performed. Here, this control circuit CPU identifies the type of incoming call and sends it to the switch circuit.
A control signal for this on/off control is given to the AS gate as follows. In other words, in the case of an incoming call from a central office line, it is turned on for 0.4 seconds,
It is controlled at the timing of 0.2 seconds off, 0.4 seconds on, and 2 seconds off, and in the case of an extension call, it is controlled at the timing of 1 second on and 2 seconds off. And this on-
Incoming signal made by off control button phone
Given to TEL ₁ to TEL ₃ ... Further, in the case of a standard telephone TEL ₅ b, a ringing signal is generated by a ringing signal generator RGO (approximately 45 Hz) shown in FIG. 6, and is expanded to a ringing signal for a standard telephone of approximately 50V. This calling signal is then sent to the standard telephone TEL _5b with two-wire connection through contacts i ₁ and i ₂ of relay I shown in FIG. 6, and drives the ringer. On the other hand, when generating a 600Hz alarm signal from the tone signal generation circuit OSC, the control circuit controls the warning sound and off-hook alarm tone.
This is done by the CPU applying an action "H" control signal to the gate of the switch circuit AS shown in FIG. These tones are sent to each 4-wire connected button telephone TEL ₁ to
The sound will be amplified from the TEL ₃ ... speaker. Next, to explain the case of incoming calls, when the standard telephone TEL ₅ b with two-wire connection of the terminal telephone TEL ₅ receives either a central office line or an extension call, the control circuit CPU sends an incoming call from port Q6 of the decoder IFC ₂ . signal
Send "H" of IDV to operate relay I shown in FIG. Therefore, the standard telephone TEL ₅ b
The off-hook signal detection circuit at the time of an off-hook call is as shown in FIG.

The off-hook signal is detected by the photocoupler PC. The call signal is sent to the control circuit CPU.
This is done by sending out the signal RSTN from the output ports _O0 to _O3 and _O6 of the decoder _IFC3 through the port Q0. When this signal RSTN becomes "H", the transistor _Q5 shown in FIG. 6 shifts to the on state,
Along with this, transistor Q ₆ is also turned on, and the midpoint tap (+) of the primary winding P of transformer T ₂ is turned on at 24V.
power is supplied. In this state, the output of the calling signal generating circuit RGO is applied to the bases of transistor Q ₁ and transistor Q ₃ , and each of these transistors Q ₁ and _{Q 3 is} turned on _. Transistors Q ₂ and Q ₄ are also turned on, and both ends of the primary winding P of transformer T ₂ are alternately connected to signal ground SG, so that
A stepped-up voltage appears in the secondary winding S of transformer _T2 , which becomes the ringing signal. This ringing signal is transmitted as shown in Figure 6: Signal ground SG - Secondary winding S of transformer T ₂ - Capacitor C ₂ - Capacitor C ₃ - Relay contact
bu - Relay contact i ₁ - Capacitor C ₄ - Standard telephone
The path TEL ₅ b - relay contact i ₂ - signal ground SG is sent to the standard telephone TEL ₅ b with a two-wire connection. When this standard telephone TEL ₅ b goes off-hook, the aforementioned off-hook signal detection circuit closes and direct current flows, causing the photocoupler to
PC turns on, transistor _Q5 turns off, and transistor _Q6 also turns off, so
Transistor through the primary winding P of the transformer T ₂
The power supply to Q ₂ and transistor Q ₄ is stopped and the ringing signal is stopped. On the other hand, when the two-wire standard telephone TEL _5b is off-hooked, the relay LE operates, and the off-hook information is sent to the control circuit CPU shown in FIG. 4 through the contact le. In other words, the output port 4 of the control circuit CPU is set to “L” for scanning.
When sending a signal, the standard telephone set shown in Figure 6
Signal DBO applied to terminal 14 of TEL ₅ b is “H”
When the output of the inverter INV becomes "L" and the relay contact le is closed, the loop signal LOOP supplied to the input port ₂ of the control circuit CPU shown in Fig. 4 becomes "L" through the diode D2. ” and detects the operation of relay LE. Here, the input port 2 of this control circuit CPU is internally pulled up. And the loop signal from this relay contact le
LOOP is a DC loop detection signal, and is an active "L" signal applied to the input port 2 of the control circuit CPU shown in FIG. Further, the signal DBO sent from the output port 4 of the control circuit CPU is an output signal for selecting or scanning the input, and is an output signal for selecting or scanning the input.
It is an active "L" signal at . Here, the signal RMD sent out through the terminal 6 from the diode _D3 forming the extension board identification section shown in FIG. Or one for two-wire connection, i.e.
This is a board identification signal to identify whether it is a standard telephone with a two-wire connection, and is active "L", that is,
If a standard telephone with a two-wire connection is installed, the inverter will
Since the output of INV becomes "L", the configuration is such that "L" is applied to the input port 11 of the control circuit CPU shown in FIG. Further, in the case of an expansion board for adding a button telephone with a 4-wire connection, since the diode _D3 is not connected to the terminal 6, "L" is not applied to the input port 11 of the control circuit CPU. In this way, by attaching an expansion board on which a button telephone interface circuit is mounted to a predetermined position on the board of the main unit KSU, it is possible to add a button telephone connected by a pair of communication lines and a pair of signal lines. An extension board is mounted on which a standard telephone interface circuit is configured, and the standard telephone interface circuit is led out to the same terminal position for the same input/output line as the button telephone interface circuit, and is led out to the individual terminal position for the dedicated input/output line. By attaching an extension board with this standard telephone interface circuit mounted to the extension board mounting the above-mentioned button telephone interface circuit and determining the board identification signal DBO, a standard telephone interface circuit that is connected by only one pair of communication lines can be established. You can add more telephones. When the control circuit CPU learns that the two-wire standard telephone TEL _5b has gone off-hook, it determines whether the incoming call is from an extension or a central office line. Yotsute control circuit section
The CPU instructs as follows. First, in the case of an incoming extension call, port Q4 of decoder IFC ₁ shown in FIG. 4 remains "H",
Therefore, the relay FE shown in FIG. 6 continues to operate at all times. That is, the contact points fe ₁ and fe ₂ are at the positions indicated by dotted lines. And relay I
The signal IDV becomes "L" at the port Q6 of the decoder IFC ₂ shown in FIG. 4, and the operation is restored. Therefore,
A standard telephone TEL ₅ b with a two-wire connection is connected to the extension line IT/PH through capacitor C ₅ and capacitor C ₆ , and the DC current is as shown in Figure 6: power supply (+) 24V - resistor R ₁₃ - Chiyoke coil T ₁
- Relay contact fe ₁ - Relay contact i ₁ - Relay LE - Standard telephone TEL ₅ b - Relay contact i ₂ - Relay contact fe ₂
It is supplied to a standard telephone TEL ₅ b with a two-wire connection through the following paths: - York coil T ₁ - Resistor R ₁₄ - Signal ground SG (ground). Next, in the case of a central office line incoming call, port Q4 of decoder IFC ₁ shown in FIG. 4 becomes "L",
Relay FE is restored, and relay I is also restored in the same way as described above, so a standard telephone with a two-wire connection
TEL ₅ b is connected to the central office line EX/PH. Then, after the call ends, when the switch is turned on, relay LE is restored and the contacts LE are opened at output port 4 and input port 2 of the control circuit CPU.
detected and returns everything to its initial state. Next, the calling operation will be explained. First, the standard telephone TEL ₅ b with two-wire connection is turned off.
As shown in Figure 6,

A loop current is supplied through the path in [Table], and a standard telephone TEL ₅ b with a two-wire connection is connected to the extension line IT/PH via capacitors C ₅ and C ₆ . Then, relay LE operates and its contact le turns off and on as described above.
The hook information is sent to the control circuit CPU shown in FIG. In this state, the handset of the two-wire standard telephone TEL _5b makes a call to the four-wire terminal key telephone, and if the other party answers, the call can be made. If an extension control circuit ICB is provided as in the embodiment shown in FIG. 4, individual extension calls can be made by dialing. In other words, since there is an extension control circuit section ICB, the resistance in the above loop circuit
It is configured to send the change in voltage drop due to _R14 (due to dialing) to the extension control circuit ICB, and send that information to the control circuit CPU. Furthermore, when tone dialing is used, the dialing tone signal is sent via the extension communication path IT/PH. Next, when acquiring a central office line from a standard telephone TEL ₅ b with a two-wire connection, as explained in the section on the case where the standard telephone is off-hook, the loop current is supplied by off-hook. In this state, the relay LE is restored for 200 to 1000 msec by hooking of the two-wire standard telephone TEL _5b , and the hooking information by the relay contact LE is sent to the control circuit CPU shown in FIG. Then, the control circuit CPU learns that the standard telephone TEL ₅ b with 2-wire connection has the intention of capturing the central office line, restores the relay FE, and transfers the standard telephone TEL ₅ b with 2-wire connection to the central office line. Connect to. Here, if an extension control circuit ICB is provided as in the embodiment shown in FIG. 4, connection to the central office line can be made by keying in the dial "7" instead of the above-mentioned hooking. be. In this case, if another 4-wire connection button telephone is using the central office line, the control circuit CPU operates relay I and relay BU shown in FIG. A busy tone is sent from the busy tone signal generation circuit BTG to _5b . This busy tone interval is determined by the busy tone signal generation circuit.
Created simultaneously with the signal within the BTG. Then, the DC current when this relay BU operates is:
As shown in Figure 6, the power supply (+) is supplied through the path of 24V - resistor R ₁₅ - relay contact bu - relay contact i ₁ - relay LE - standard telephone TEL ₅ b - relay contact i ₂ - signal ground SG, The busy tone is applied from the busy tone signal generating circuit BTG to the standard telephone TEL _5b through a resistor _R3 and a capacitor _C1 . When the standard two-wire telephone HEL ₅ b turns on after hearing this busy tone, everything returns to its initial state. Note that transfers can also be made from other key telephones. As is clear from the above description, according to the present invention, by replacing the telephone control unit in the main unit KSU, it is possible to replace a button telephone with a control button with a 4-wire connection to a standard telephone with a 2-wire connection. By replacing units of the same size in the same location, one extension can be used for either a 4-wire button telephone or a 2-wire connection, saving space for installation. Since it is advantageous in terms of aspects, the practical effect is extremely large. In addition, there is no need to provide a dedicated control circuit inside or outside the main device, unlike the two-wire long-distance telephones included in conventional button telephones, which simplifies the configuration. It is extremely effective in terms of being economical.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the basic configuration of an embodiment of a button telephone device to which the standard telephone addition method according to the present invention is applied, and FIGS. 2 and 3 show a standard telephone addition method in the button telephone device according to the present invention. FIG. 4 is a configuration diagram showing a specific configuration of an embodiment of the present invention, and FIGS. 5 and 6 are related to a button telephone and a standard telephone in the embodiment shown in FIG. 4. It is a circuit diagram showing extracted parts. KSU……Main unit, TEL ₁ ~ TEL ₃ , TEL ₅ a……
Key telephone, TEL ₅ b...Standard telephone, IFC ₁ ~
IFC ₃ ...decoder, CPU...control circuit section.

Claims (1)

[Scope of Claims] 1. A first expansion board on which a button telephone interface circuit is mounted is attached to a predetermined board position of the main device and connected to the control unit, thereby connecting a pair of communication lines and a pair of signal lines. In a key telephone device which is configured to add a key telephone to be connected to a telephone, the loop current supply means supplies a loop current to a telephone line, and the hook state detection means detects the hook state by detecting the loop current. a ringing signal generator that generates a ringing signal in response to an incoming call control signal supplied from the control section; and a line that switches the telephone line from the main device side to the ringing signal generator when the ringing signal is sent. a standard telephone interface circuit having a switching means and a board identification signal generation means for generating a board identification signal indicating that the circuit is for a standard telephone; A second extension board is provided in which terminals and board identification terminals are assigned as terminals different from terminals of the button telephone interface circuit, and this second extension board is installed at the position of the first extension board. The control unit determines the board identification signal that is output when the control unit controls the second extension board as one for the standard telephone, thereby making it possible to add a standard telephone. Standard telephone extension method for button telephone equipment.