JPH0310274B2 - - Google Patents

Description

[Detailed description of the invention]

[Technical Field of the Invention] The present invention relates to a signal transmission system for a button telephone device in which signals are transmitted between a main device and a button telephone device using pulse signals each having a plurality of bits. [Prior Art] When transmitting signals between a main device and a key telephone (hereinafter referred to as a telephone), as the device becomes larger or more sophisticated, signal transmission is generally performed using coded multi-bit pulse signals. This requires both the main unit and each telephone to have encoding and decoding functions, which makes the configuration complex and expensive, and if an error occurs in the signals sent from the telephone. However, the request for operating the telephone is not accurately transmitted to the main device, resulting in disadvantages such as the inability to make a call or the operation of the entire device becoming inaccurate. [Summary of the Invention] The present invention has the purpose of fundamentally solving such drawbacks of the conventional technology, and the transmission signals from the main device are control data for controlling the lighting of the indicator light of the telephone, controlling the transmission of audible sounds, etc. Note that if there are repeated transmissions, even if an accidental error occurs, the indicator lamp lighting, audible transmission, etc. will only be interrupted for a short time and will not cause any particular problem. The signals are repeatedly transmitted in each cycle of signal transmission corresponding to each control item, while the signals transmitted from the telephone are continuously transmitted multiple times within one cycle as coded data according to the operating status. The receiving main device determines that the signal is a legitimate signal based on the matching of each data.
The present invention provides an extremely effective signal transmission system for a button telephone device that simplifies the configuration and improves the reliability of signals transmitted from the telephone. [Example] Hereinafter, details of the present invention will be explained with reference to figures showing examples. FIG. 1 is a block diagram of the main unit KSU, in which the housed office lines L ₁ and L ₂ are connected to the main telephones TE _n1 and TEL _n2 by switching keys K ₁ and K ₂ and the telephones TEL ₁ to _{TEL 8.}
Telephone TEL ₁ used as a power outage telephone,
Direct key K ₃ , K ₄ for direct connection to TEL ₂
It is connected to the dial circuits DIC ₁ and DIC ₂ via the dial circuits DIC 1 and DIC 2, and then to the first and second office line links LK _L1 and LK _L2 . In addition, the main unit KSU and each telephone not shown in the diagram
Between TEL ₁ to _{TEL 8} , there is a pair of communication lines Lt ₁ to Lt _8.
and are connected to each other by signal lines Ls ₁ to Ls ₈ , an extension link LK _I for mutual exchange connection between the telephones TEL ₁ to _{TEL 8} , an amplifier CA for amplifying the ringing voice, and a switching circuit SW1 to
Audible signal transmission circuit and telephone device consisting of SW3, ring tone generator RTG, amplifier TA for tone transmission, etc.
Tolling for exchange connection with TEL ₁ to TEL ₈
LK _T is provided for each communication line Lt ₁ to _{Lt 8} and each link.
Between LK _L1 , LK _L2 , LK _I , and LK _T , call lines Lt ₁ to Lt ₈ are individually selected between the central office link LK _L1 and LK _L2 side and the extension link LK _I and tone link LK _T side. Contacts of selection latching relays XS1 to XS8 to connect
_xs1 ^{0 , xs1 1} _{_} ^{_ _ _ _} line lt ₁
~ Connection latching relay XC1 that selectively connects Lt ₈ to either station link LK _L1 or LK _L2 ~
Contacts xc1 ⁰ , ^{xc1 1} xc8 ⁰ , ^{xc8 1} of _XC8 are inserted, and between contacts xs1 ⁰ , xs1 ¹ _to
Lt ₁ ~ _{Lt 8} as extension link LK _I and tone link
Contacts xi1 ⁰ , xi1 ¹ -xi8 ⁰ , and xi8 ¹ of connection relays XI1 to XI8 are inserted to selectively connect each one to one of LK _T. In addition, latching relays XS1~XS8, XC1~
XC8 and relays XI1 to XI8 each
The latching relays XS1 to XS8 are provided in correspondence with TEL ₁ to TEL ₈ , and the latching relays XS1 to XS8 are connected to the central office links LK _L1 and LK _L2.
When side is selected, latching relay XC1~
Depending on the XC8 situation, central office line L ₁ or L ₂ and telephone
When TEL ₁ to TEL ₈ are exchange connected and latching relays XS1 to XS8 select extension link LK _I and tone link LK _T side, relays XI1 to XI8
Depending on the operation or recovery, telephones TEL ₁ to _{TEL 8} are connected to extension link LK _I or tone link LK _T , and calls are made between telephones TEL ₁ to _{TEL 8} using the telephone power supply from transformer TL. At the same time, a call was also made to the Aphone DRP (not shown in the figure) via the doorphone circuit DPC, and when the tone link LK _T was connected, the ions of the switch circuit SW1 were used to receive the call voice from the doorphone DRP, When the switching circuit SW2 is turned on, a call voice from another telephone is received, and when the switching circuit SW3 is turned on, a ringing tone indicating an incoming call is received from the office lines _L1 and _L2 . In addition, for the office lines L ₁ and L ₂ , the switching keys K ₁ ,
An incoming call detection unit RDT for detecting the arrival of a calling signal is bridge-connected between K ₂ and direct keys K ₃ and K ₄ , as well as dial circuits DICD ₁ and DIC ₂ and central office line links LK _L1 and LK. Between _L2 and H1, there is a hold relay H1,
Contacts h ₁ ⁰ , h ₁ ¹ , h ₂ ⁰ , h ₂ ¹ of H2 and resistors R ₁ , R ₂ for DC loop closure are connected in parallel,
By the operation of relays H1 and H2, station lines L ₁ and L ₂ are held, and at the same time, via capacitors C ₁ and C ₂ ,
On hold music is sent from the on hold music generator HTG. In addition, as the dial circuits DIC ₁ and DIC ₂ , depending on the conditions of the office lines L ₁ and L ₂ , if a pulse signal is used as the dial signal, a circuit that sends out a pulse signal by turning on and off the DC loop is used. ,
If a composite audio frequency signal is used as the dialing signal, a circuit is used that is operated by a loop current and sends out the composite audio frequency signal. On the other hand, processors such as microprocessors
CPU, fixed memory ROM and variable memory RAM
The processor CPU executes instructions stored in the fixed memory ROM and performs control operations while accessing predetermined data to the variable memory RAM. By exchanging data with _the transmission unit _{SR via}
In addition to accepting operation data from TEL ₈ , the detection power of the incoming call detection unit RDT and the doorbell circuit
Accepts operation signals from the DPC, makes control decisions accordingly, and sends control data for telephones TEL ₁ to _{TEL 8} to the transmission unit SR,
Each latch relay XS1~XS8, XC1~XC8, relay XI1~XI8, H1, H2, dial circuit DIC ₁ ,
DIC ₂ , hold tone generator HTG, switch circuit SW1~
It controls SW3 and the door phone circuit DPC, etc., and performs switching connections, sending out dial signals, and placing calls on hold in response to operations on telephones TEL ₃ to _{TEL 8} . Note that the interface I/F is also given alarm signals AL from external door switches, fire detectors, etc., and the processor
CPU sends control data, telephone TEL ₁ ~
In addition to transmitting an alarm sound from TEL ₈ , an external buzzer BZ is sounded via the interface I/F to issue an alarm. In addition, commercial power AC via power switch SW _P
is a DC power supply for +19V, +12V, +5V, etc. after being stepped down, rectified, and stabilized in the power supply PS.
DC power +19V is supplied to each part of the telephones TEL ₁ to TEL ₈ through signal lines Ls ₁ to Ls ₈ in the transmission unit SR. However, a backup battery BAT is provided for the volatile variable memory RAM that stores important data for control, and even in the event of a commercial power AC power outage, the stored contents can be saved by backing up the battery BAT. It is meant to be retained. In addition, specific power outage telephones TEL ₁ and TEL ₂
is equipped with a diagram circuit that operates by loop wires passing through the telephone lines Lt ₁ and Lt ₂ , but if one is for pulse signals and the other is for composite audio frequency signals, if the telephone for pulse signals is When a composite audio frequency signal is dialed, it is connected to a central office line, and if a power outage occurs while a telephone set for composite audio signals is connected to a central office line that uses a pulse signal as a dialing signal,
Since dialing to the office line from each station line is impossible, a switch K _P for switching the office line connection is provided, and when operated, the latching relay XC1,
XC2 is controlled and the telephone is connected to the mutually compatible central office line.
TEL ₁ and TEL ₂ are supposed to be connected,
At the same time, the holding latching relay DU is also controlled, so when the commercial power supply AC is turned on, the processor CPU checks the state of the contact du of the latching relay DU, and accordingly the switch K _P After determining whether or not the latching relays XC1 and XC2 have been operated, if they have been operated, the data indicating the status of the latching relays XC1 and XC2 stored in the variable memory RMA and held therein is corrected. In addition, a setting section FST is provided, which allows special conditions such as incoming call restrictions to be set for each of the telephones TEL ₁ to TEL ₈ , and the output of this is sent to the control section.
It is given to CNT, and control is performed according to the setting situation. Figure 2 is a specific circuit diagram of the transmission section SR,
A resistor R ₁₁ with a resistance value and a transistor Q ₁₁ as a switching element are inserted in series between the non-common side line of the signal line Ls ₁ and the DC power supply +19V, and control data DS ₁ is normally sent from the control unit CNT. is “L” (low level) and the output of inverter IN ₁₁ is “H” (high level), so the light emitting diode
LD ₁₁ and voltage regulator diode ZD ₁₁ are off, transistor Q ₁₁ remains on due to forward bias through resistor R ₂₁ , and power is supplied to signal line Ls ₁ through fuse F ₁₁ . It has become a thing. Regarding the above, when the control data DS ₁ becomes "H" in a pulsed manner, the output of the inverter IN ₁₁ becomes "L" accordingly, the light emitting diode LD ₁₁ and the constant voltage diode ZD ₁₁ turn on, and the transistor In order to lower the base voltage of Q ₁₁ to the Zener voltage of the constant voltage diode Z ₁₁ , the collector-emitter resistance of transistor Q ₁₁ increases accordingly, and the line voltage Vs decreases, causing intermittent power supply. This is transmitted as a transmission number, and its status is displayed by light emission from the light emitting diode _LD11 . Note that the diode _D11 is for clamping the voltage of the non-common side line to the Zener voltage of the constant voltage diode _ZD11 when the collector-emitter resistance of the transistor _Q11 increases. On the other hand, a receiving circuit is configured by resistors R ₁₃ to R ₁₅ , capacitor C ₁₁ , transistor Q ₁₂ , and diodes D ₁₂ and _{D 13} , and when transistor Q ₁₁ is in the on state, the signal line
When transmitting by changing the line impedance of Ls ₁ in a pulsed manner, the terminal voltage of resistor R ₁₁ increases as the line impedance decreases, and the resistor
Since the line side of _R11 becomes "L" in a pulsed manner, this passes through the capacitor _C11 and is applied as a forward bias to the base of the transistor _Q12 , turning on the transistor _Q12 , and the collector current flows through the resistor.
The terminal voltage of _{the resistor R 15 is} applied to _{the control part CNT as operation data DR 1 through} which reception is performed. Note that diode D ₁₂ is for protection of transistor Q ₁₂ , and diode D ₁₃ is for operation data
This is to clamp the peak value of DR ₁ with the DC power supply +5V. In addition, the control unit CNT monitors the presence or absence of errors in the operation data DR ₁ by parity checking and matching with each byte, and when an error is detected, the reset signal RST ₁ is set to “H” for a certain period of time, and the inverter IN ₁₂ In order to change the output to "L", the transistor _Q11 is turned off, the non-common side line is connected to the common potential via the diode _D11 , and the power supply is completely cut off for a certain period of time. Therefore, the circuit of the telephone TEL ₁ is set when the power is turned off, and when the power supply is resumed after a certain period of time, it is initialized and starts operating, thereby eliminating the error state. As described above, the transmitter/receiver circuit SRC ₁ alternately transmits and receives signals to and from the telephone TEL ₁ , but similar transmitter/receiver circuits SRC ₂ to SRC ₈ are provided for each signal line Ls ₂ to _{Ls 8} , and are controlled by the control unit CNT. In response to data DS ₂ to DS ₈ and reset signals RST ₂ to RST ₈ , telephone TEL ₂
In addition to transmitting signals to TEL ₈ and performing reset operations, it also sends out operation data DR ₂ to _{DR 8} in response to transmission signals from telephones TEL ₂ to TEL ₈ . In addition, signal transmission and reception with telephones TEL ₁ to _{TEL 8} is as follows:
This is done individually and sequentially under the control of the control unit CNT, and this is repeated at a constant cycle. FIG. 3 is a circuit diagram of telephones TEL ₁ to TEL ₈ , and line terminals TT ₁ and TT ₂ connected to the communication line Lt.
Includes a switch HS ¹ , a diode bridge
Call circuit TKC via DB and dial circuit DIC
is connected, and depending on the off-hook call circuit
The TKC closes the DC loop, and the dial circuit DIC, which operates using the loop current as a power source, can make a dial call, and the transmitter T and receiver R can make calls. However, the dial circuit DIC is a photocoupler.
It is controlled by a PC light-receiving transistor and can only operate during a commercial AC power outage. Still, on the line side of the diode bridge DB, connect the capacitor C ₁₀₁ via the switch HS ² .
A tone ringer TRG is bridge-connected via the resistor R ₁₀₁ and operates with the power of this in response to the arrival of a ringing signal, generates a ring tone, and connects the transformer T ₁₀₁ and the contact pf ² of the relay PF. A transformer T ₁₀₂ is provided, which is also connected via a contact pf ⁰ and a capacitor C ₁₀₂ , by means of which the audio signal is extracted. Switch circuit SW ₁₀₁
and potentiometer RV ₁₀₁ to amplifier A, where it is amplified and then connected to the capacitor.
The speaker SP is driven through C ₁₀₃ and contact pf ² . On the other hand, the line terminal TS ₁ to which the signal line Ls is connected,
A stabilizing circuit consisting of a transistor Q ₁₂₁ , a resistor R 121 , a capacitor C ₁₂₁ , C ₁₂₂ and _{a constant voltage diode ZD 121 is connected to TS 2 via a diode D 121 for blocking the} application of reverse polarity and a blocking wire CH. As a result, the power supplied from the main unit KSU is stabilized to the local power supply +12V and supplied to each necessary part, and the output of this is further supplied to the local power supply by the integrated circuit stabilization circuit REG. It is stabilized to +5V, smoothed by capacitor C ₁₂₃ , and then supplied to the necessary parts, and the main unit KSU control section
The control unit CT, which is similar to the CNT but smaller in scale, is also operated by a local power supply of +5V. Note that the terminal voltage of a capacitor C ₁₂₄ charged by the local power supply +5V is applied to the reset terminal of the control unit CT via a resistor R ₁₂₂ to which a diode D ₁₂₂ for rapid discharge is connected in _parallel . The delay in voltage rise at the terminal of capacitor C ₁₂₄ , which occurs at the start of power supply, is used as an "L" reset pulse, and in response to this, the control unit CT performs the reset and initialization as described above. In addition, a capacitor is connected between line terminals TS ₁ and TS ₂ .
C ₁₂₅ , C ₁₂₆ , resistor R ₁₂₄ ~ R ₁₂₉ , diode D ₁₂₃ ,
D ₁₂₄ , transistor Q ₁₂₂ , inverter IN ₁₂₁ , input inversion type OR gate G ₁₂₁ , and NAND gate
A receiving circuit with G ₁₂₂ is connected, and _{an inverter IN 122 and} a resistor R ₁₃₁ ~
A transmission circuit including R ₁₃₅ and transistors Q ₁₂₃ and Q ₁₂₄ is connected to the main unit KSU, and the _transistors
When Q ₁₂₂ is turned on and the terminal voltage of resistor R ₁₂₆ becomes “H” due to the flow of collector current, the output of inverter IN ₁₂₁ changes to “L”, and the current that has been charged through diode D124 is changed to “L”. Capacitor C ₁₂₆
is discharged through the resistor R ₁₂₇ and the output impedance of the inverter IN ₁₂₁ , and the charge on the capacitor C ₁₂₆
The terminal voltage of capacitor C ₁₂₆ decreases to “L” according to a time constant determined mainly by the values of resistor R ₁₂₇ and R ₁₂₇ . When the terminal voltage is applied as “L” to one input of OR gate G ₁₂₁ through resistor R ₁₂₈ , the gate
A flip-flop circuit (hereinafter referred to as FFC/FF) consisting of _G121 and NAND gate _G122 is set,
“L” control data is sent to the control unit via resistor _R129 .
Given to port terminal P10 of CT. When the control unit CT confirms the control data, it changes the port terminal P6 to "L" and resets the FFC and FF, thereby preparing to receive the next control data. Furthermore, if port P7 is pulsed to "L" in accordance with the operation data, the output of inverter IN ₁₂₂ becomes "H", which turns on transistor Q ₁₂₃ and turns on transistor Q ₁₂₄ as well. ,
A resistor R ₁₃₅ is connected between the line terminals TS ₁ and TS ₂ via a diode D ₁₂₁ to reduce the line-to-line impedance of the signal line Ls, thereby transmitting the transmission signal. As described above, signals are transmitted and received with the main unit KSU, and port terminal P8 of the control unit CT
The switch HS ³ is connected to the input terminal K0.
~ K3 is connected to the output of the keyboard KB, and output terminals S0 to S3 are connected to diodes D ₁₅₁ ~
The scanning input of the keyboard KB is connected through _D154 , and the local power supply +5V is applied through the pull-up resistor r to each terminal, which is set to “H”.
P8 among P8, K0 to K3 turns "L" in response to the ON of the hook switch HS ³ , thereby detecting off-hook, and output terminal S0 at a predetermined period.
~ S3 is sequentially set to "L" and scanned, and accordingly, input terminals K0 to K3 are checked to see if they have become "L", and dial keys *, #, 1 to 9 connected in a matrix are pressed. , 0 and speaker key
It detects that the Ks, hold key _KH , central line key _KL1 , and _LL2 are turned on, and according to these operating conditions, the operation data is encoded and transmitted as a transmission number as described above. In addition, a transistor Q ₁₅₁ is connected to the output terminal S4 via a resistor R ₁₅₁ , and the output terminals S1 to S3 are
Transistors through the circuit of resistors R ₁₅₂ to R ₁₅₇ , respectively
Q ₁₅₂ to Q ₁₅₄ are connected, and the output terminal S4 is set to "L" and the transistor Q ₁₅₁ is turned on at a timing separate from the scanning of the keyboard KB, and the light emitting diodes corresponding to the office line keys K _L1 and K _L2 are connected. When the local power supply +5V is applied to the light emitting diode LD ₁₀₃ corresponding to LD ₁₀₁ , LD ₁₀₁ and the speaker key Ks, if the output terminals S1 to S3 are set to "L" according to the control data, the transistors _Q152 to _Q154 When turned on, the light emitting diodes LD ₁₀₁ - _{LD 103} emit light by energization through the resistors R ₁₅₈ - R ₁₆₀ , and the station lines L ₁ and L ₂ are captured by the continuously visible light emission of the diodes LD ₁₀₁ and LD ₁₀₂ . The same intermittent light emission will be used to display these pending conditions, and the same continuous light emission from the same diode LD ₁₀₃ will cause the speaker SP to
Displays the reception amplification status. On the other hand, depending on the control data, port terminals P5, P1,
When P0 is set to "L", each of the switch circuits SW ₁₀₁ to SW ₁₀₃ is turned on, and the port terminal
Depending on “L” of P4, transistors Q ₁₇₁ and Q ₁₇₂
A switching circuit including resistors R ₁₇₁ to _{R 174} is driven, and when transistor Q ₁₇₂ is turned on, transistor Q ₁₇₁ is also turned on, and local power supply +12V is supplied to amplifier A, making it operational. Also, inverter IN ₁₇₁ ~ IN ₁₇₄ , resistor R ₁₇₅ ~
Oscillator that generates tone signals of different frequencies using R ₁₇₈ and capacitors C ₁₇₁ and C ₁₇₂ .
OSC ₁₀₁ and OSC ₁₀₂ are configured and the port terminal
The NOR gates G ₁₇₁ and G ₁₇₂ are turned on by “L” of P2 and P3, and the tone signal passes through these and also passes through the AND gate G ₁₇₃ of inverted input type, and when the switch circuit SW ₁₀₂ is on, the tone signal is passed through the resistor. ware R ₁₇₉ ,
Applied to amplifier A via R ₁₈₀ , low level drives speaker SP, and when switch circuit SW ₁₀₃ is on, applied to amplifier A only through resistor R ₁₇₉ , high level drives speaker SP. do. Furthermore, depending on whether switch circuit SW ₁₀₁ is turned on,
The station line incoming call tone sent from the main unit KSU via the communication line Lt, the incoming call tone from the door phone DRP, the voice ring tone, the received voice, etc. are emitted from the speaker SP.
When the switch circuit SW ₁₀₂ or SW ₁₀₃ is turned on and the NOR gate G ₁₇₁ is turned on, the hold alarm sound, the unhooked alarm sound, the alarm sound corresponding to the alarm signal AL, etc. are emitted from the speaker SP, and the NOR gate G 171 is also turned on.
If gate G ₁₇₂ is turned on, the touch tone and extension ring tone when operating the dial keys on the keyboard KB will be emitted from the speaker SP, and if NOR gates G ₁₇₁ and G ₁₇₂ are turned on at the same time, a busy call will be emitted. Sounds are emitted at the same time. However, to distinguish between each emitted sound, NOR gate G ₁₇₁ ,
It is determined by changing the on/off period of G ₁₇₂ and setting the intermittent status. In addition, terminals M, G, +, - are pulled out for connection to an external loudspeaker system, and a local power supply of +12V is supplied via resistor _R191 .
A switching circuit consisting of R ₁₉₂ , R ₁₉₃ and transistor Q ₁₉₁ controls the power supply return path, and the output terminal
When S7 is set to "L", transistor _Q191 is turned on and the external loudspeaker is put into operation. In addition, the output terminal S6, which maintains "H" while the local power supply +5V is being supplied, is connected to the input of the inverter IN ₁₇₅ , and when the commercial power supply AC is energized, the output of this becomes "L", and the resistor R ₁₉₄ , R ₁₉₅ turns on the transistor Q ₁₉₂ , operates the relay PF to which the surge absorption diode D ₁₉₁ is connected in parallel, and also energizes the light emitting diode of the photocoupler PC through the resistor R ₁₉₆ . The light emitted by this turns on the light-receiving transistor of the photocoupler PC and stops the operation of the dial circuit DIC. In addition, according to the operation of relay PF, contact pf ⁰ is on and contact pf ² is in a state to select the output of amplifier A, and when switch circuits SW ₁₀₁ to _{SW 103} are turned on, speaker SP is driven as described above. On the other hand, if the relay PF is restored due to a power outage in the commercial power AC, contact pf ⁰ turns off and contact pf ² turns off the tone ringer.
The TRG output is selected, and the main unit KSU
The speaker SP is driven only in response to an incoming call from the central office line _L1 or _L2 which is directly connected to the dial circuit DIC. If you operate the dial key on the keyboard KB after off-hook, a separate contact provided on it will turn on and send out a dial signal in the form of a pulse signal or composite audio frequency signal, so even in the event of a power outage, the central office line _L1 or You can freely make and receive calls to _L2 . Tasashi, dial circuit DIC, tone ringer
TRG, relay PF, and their peripheral circuits are
It may be provided only in power outage telephones. Figure 4 shows the main unit KSU and telephones TEL ₁ to _{TEL 8} .
It is a diagram showing the transmission situation of signals between
First, a polling signal PR is sent from the main unit KSU to the telephone TEL ₁ , and the telephone
When a response signal X indicating operation data is transmitted from TEL ₁ , upon reception of this, the main unit KSU sends a control signal Y indicating control data to the telephone TEL ₁ .
and send/receive these using the telephone TEL ₂ ~
TEL ₈ is also carried out sequentially, and the above transmission and reception is repeated at a constant period t. FIG. 5 is a waveform diagram showing details of a series of polling signals PR field to control signal Y.
For transmission from KSU, the line voltage Vs of the signal line Ls is reduced by V1, while for transmission from the telephone TEL, the line voltage Vs is reduced by _V2 . Here, the polling signal PR is composed of a 3-bit pulse signal, and the response signal X is
It consists of a 2-bit start signal ST and bytes X1 and X2, each consisting of a synchronization bit SY, data bits _D0 to _D6 , and parity bits PY, and data bits _D0 to _D6 are The data bits D ₀ to D 6 are encoded and the insertion or non-insertion of the data bits D 0 to _{D 6} is determined accordingly. For example, insertion indicates a logical value of “1” and non-insertion indicates a similar “0”. In addition to that,
For the first byte X1 and the second byte X2, the insertion and non-insertion of data bits D ₀ to D ₆ are reversed, and even if the codes indicated by each are the same, the bytes X1 and X2 are inversely correlated to each other. It is supposed to be sent as. Furthermore, the control signal Y is a 2-bit start signal.
ST and each synchronization bit SY, data bit
Byte Y1 consisting of D ₀ to D ₆ and parity bit PY
~ Y3, and a total of 21 data bits are defined as corresponding to each control item, and for example, a logical value is indicated in the same way as described above depending on insertion or non-insertion, and this logical value "1" The control item is set to be executed accordingly. Therefore, the code of bytes X1 and X2 indicates the operational data of the telephone, and the codes of bytes Y1 to Y3
Control data is indicated by each data bit _D0 to _D6 , and the control item and byte Y1
The correspondence relationship with each data bit D ₀ to D ₆ of ~Y3 is as follows:
For example, it is determined as shown in the table below.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, the encoding and decoding means for transmitting control data are simplified, the cost of the device is reduced, and errors in operation data can be detected easily and reliably. , the operation of the device becomes more accurate, and a remarkable effect can be obtained in various key telephone devices.

[Brief explanation of the drawing]

The figures show an embodiment of the present invention, in which Figure 1 is a block diagram of the main device, Figure 2 is a circuit diagram of the transmission section in Figure 1, Figure 3 is a circuit diagram of a telephone, and Figure 4 is a signal transmission diagram. FIG. 5 is a diagram showing the waveform of the transmission signal, and FIG. 6 is a flowchart showing how the processor determines whether each byte matches. KSU...Main unit, Ls ₁ to Ls ₈ ...Signal line, TEL ₁
~TEL ₈ ...Telephone (button phone), CNT, CT
...Control unit, CPU...Processor, SR...Transmission section, _R11 to _R15 , _R131 to _R135 ...Resistor, _C11 ...
Capacitor, Q ₁₁ , Q ₁₂ , Q ₁₂₃ , Q ₁₂₄ ... Transistor, IN ₁₂₂ ... Inverter, X1, X2, Y1
~Y3...Byte, _D0 ~ _D6 ...Data bit.

Claims (1)

[Claims] 1. In a button telephone device in which signal transmission between the main device and the key telephone device is carried out periodically using a pulse signal of multiple bits, each signal transmitted from the main device is treated as a bit corresponding to a control item for each cycle. The transmission numbers from the key telephone are repeatedly transmitted as coded data according to the operation status multiple times within one cycle, and the main device that receives the transmission receives a signal based on the coincidence of each data. A signal transmission method for a button telephone device that is characterized by determining the signal as a legitimate signal.