JPS6124351A - Signal transmission system of key telephone equipment - Google Patents

Abstract

PURPOSE:To attain accurate and sure reception of a data bit by blocking the confusion between each transmission control signal and a data bit and mis- recognition of each transmission control signal during the reception of the data bit. CONSTITUTION:The order of reception is decided for a polling signal PR, a start signal ST and bytes X1, X2, Y1-Y3 in response to each flag when a master equipment KSU and telephone sets TEL1-TEL8 are in the reception side. Then each head bit and a synchronizing bit SY of the polling signal PR and the start signal ST are detected and the execution of an interruption routine is started. Bit intervals t1-t3 and bit numbers are detected based on each head bit and the polling signal PR, the start signal ST and synchronizing bit SY are discriminated based thereupon and then the signals PR, ST and synchronizing bits SY and data bits D0-D6 are discriminated surely.

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 that transmits and receives control signals between a main device and a button telephone device.

[Prior art]

When transmitting signals between the main device and key telephones (hereinafter referred to as telephones), as the devices become larger and more sophisticated, polling signals are sent from the main device to multiple telephones in sequence. , depending on the situation, the telephone transmits a transmission signal indicating the operation status of the telephone.
Generally, the main device monitors the received signal for errors and returns a confirmation signal such as a CLK or 1NAcK signal depending on the result.

However, according to this method, since it is necessary to send a confirmation signal from the main device, the time required for signal transmission with the same telephone will be extended due to distortion, and when a large number of telephones are installed, the transmission cycle of the polling signal will be long. ab, the main device cannot promptly recognize changes in the operating status of each telephone, resulting in a disadvantage that the response of the main device is delayed.

As a countermeasure to this problem, a method has been proposed in which various transmission control signals and data bits are transmitted in series according to a predetermined order without using ACK or NACK signals, and thereby the necessary information is sent and received. ``Signal transmission system for button telephone equipment'' (patent application filed in 1973)
9-69978).

However, in the past, each bit interval of the polling signal and start signal used as a transmission control signal was the same as the data bit interval, and it was easy to misunderstand the difference between them. This causes errors in the reception of data bits, and because the order of each control signal is not particularly determined, it is easy to confuse each bit of the data bit with the synchronization bit that is transmitted before the data bit. The disadvantage is that the reception of data bits is prone to errors.

[Summary of the invention]

The present invention has an object of fundamentally solving such conventional drawbacks, and on the transmitting side, each transmission control signal has a bit interval different from the data bit interval, and each transmission control signal is composed of a plurality of bits and transmitted, On the receiving side, the first bit of each transmission control signal is detected in accordance with the transmission order, the bit interval with the subsequent bit is detected, and the type of each transmission control signal is determined based on the order and bit interval. The present invention provides an extremely effective signal transmission method for a button telephone device.

〔Example〕

Hereinafter, the present invention will be explained in detail with reference to figures showing examples.

FIG. 1 is a block diagram of 8U in the main unit, the housed office line lm2 is the main telephone unit 1m, 2 is the switching key KI+ with the telephone unit m2, and the telephone unit r to TEI.

3. Connect the telephone meter used as a power outage telephone directly to the power outage telephone. are connected to the dialing circuits DIC, , DIC2 through them, and then to the first and second office line links LKt, 1, L.
Kt,2.

In addition, the main device is 8U and each telephone metering device 8 which is omitted in the diagram.
L1 is connected to each other by one pair of telephone lines Lt+ to Lts+ and signal lines Lll to L118, respectively, and an extension link LK1 for establishing an exchange connection between the telephone sets 1 to 1, and a calling line Amplifier CA for audio amplification,
Switch circuit SWI~s'w3, ring tone generator RTG,
) - A tone link LKT is provided to perform an exchange connection between an audible signal sending circuit consisting of an amplifier TA, etc., and telephone equipment 1 to 1, and each telephone line Lt I"Lt is provided.
s and each link LKL1 + LKLz + LKI r
Between the LKT and the central office line link LKLI + LxL,
contacts X@1', 18 of selection latching relays
11~X88°.

XB8" is provided, and a contact X
The telephone lines Lt1 to Lt8 are connected to the central office links LK1 and LK1 through
Connection latching relays XCI to XC8 contacts XO1'+xc1'' to be selectively connected to either LKL2
za8°+): e8' is inserted, contact X1ll°l
Xal'~x118°+Xs8" and extension links I, KI
Similarly, there are contacts xil°+ ~xi8
°, xi8” are inserted.

In addition, latching relays X81~XS8, XCI~
XC8 and relays XII to XI8 are provided correspondingly to telephone equipment 1 to TRI, respectively, and latching relays XSI to XSa are connected to central office line links LKL1 to TRI. , L
When selecting KLZ side, latching relay XCI~
Depending on the XCS situation, central office line L1''& Takem2 and telephone equipment.

～Setting 8 is exchanged and connected, and latching relay XSI～
When XS8 selects the extension link LKI and tone link LKT side, depending on the operation or recovery of relays XII to XI8, the extension link LKI or tone link LK
Telephone stations 1 to 1 are connected to T, and by supplying power for telephone calls by transformer TL, calls are made between the telephone stations 1 to 1, and the door phone DRP (not shown in the figure) is connected via the door phone circuit DPC. Calls will also be made, and when connected to Tone Link LKT, the door phone DR will be activated by turning on the switch circuit SWI.
Receives a calling voice from P, depending on switch circuit so-called 2 being turned on, receives a calling voice from another telephone, switch circuit SW
3 is turned on, an incoming call reception indicating an incoming call from the central office line L1+L2 is performed.

Further, for the office line L1+Lz, an incoming call detection unit RDT for detecting the arrival of a calling signal is connected between the switching key Kl + 2 and the direct key 8 + K4, and the dialing circuit DIC1, DIC, and central office link LK
Holding relays H1 and H are connected between LI + LKL2.
2 contacts h1°, 111', 112°, h21 and DC loop closing resistors R1, R2 are connected in parallel, and the multi-station line L1.2 is connected in parallel by the operation of relays H1, H2.
At the same time as Lz is held, capacitor C1+0
2, the hold tone from the hold tone generator HTG is sent out.

In addition, as the dial circuits DIC1 and DIC2, when a pulse signal is used as a dial signal according to the conditions of the office line Ll r R2, a circuit is used that sends out a pulse signal by turning on and off a DC loop, and as a dial signal. If a composite audio frequency signal is used, a circuit is used that is operated by a loop current and sends out the composite audio frequency signal.

On the other hand, a processor CPU such as a microprocessor.

A control unit CNT consisting of a fixed memory ROM and a variable memory RAM is provided. The transmission section S performs control operations and connects via the interface ■7.
By exchanging data with R, it accepts operation data from the telephone 9 meter device via signal lines L31 to L118, and
Detection output of incoming call detection unit RDT and door phone circuit DP
It accepts the operation signal from C, makes control decisions based on it, sends control data for telephone postfixes 8 to 8 to transmitter SR, and sends control data to each latching relay XSI.
~XSS.

XCI~XCS, Relay XII~XI8, Hl
, R2, controls dial circuit DICI + DIC2 + hold tone generator HTG, switch circuits sw1 to SW3, door horn circuit DPC, etc.,
It performs switching connections, sending out dial signals, and placing calls on hold in response to operations.

Note that the interface I/F is also given an alarm signal AL from an external door switch, fire detector, etc. In response to the occurrence of this, the processor CPU sends control data and the telephone TF:Ls - An alarm sound is sent from the station s, and an external buzzer BZ is sounded via the interface INF to issue an alarm.

In addition, the commercial power supply AC via the power supply switch SWp is stepped down, rectified, and stabilized in the power supply section ps, and then +1
It can be supplied externally as a DC power supply of 9V, +12V, +5V, etc., and can also be used for telephone installations.
In the transmission section SR, a DC power supply of +19V is supplied to each signal line LSI to 1Lss.

However, for the volatile variable memory RAM that stores important data for control, a backup battery BAT is required.
The battery DAT can be used even during a power outage of commercial power
(by backing up) the stored contents are retained.

In addition, this particular telephone set for power outages is equipped with a dial circuit that operates on the loop current through the communication line Li1+Ltz, one for pulse signals and the other for complex audio frequency signals. In the case of a telephone set for pulse signals, if the telephone set for pulse signals is connected to a central office line that uses a composite audio frequency signal as a dialing signal, and the telephone set for composite audio signals is connected to a central office line that uses a pulse signal as a dialing signal. In the event of a power outage, it will be impossible to make dial calls from each office line, so a switch Kp for switching between office line connections is installed.
When you operate this, 2 switching relays - XCI.

XC2 is controlled and the telephone 'rEL is sent to the mutually corresponding office line.
,.

At the same time, the latching relay DU for holding is also controlled, so the processor CPU determines the state of the contact DU of the latching relay DU in response to the energization of the commercial power supply AC. It is determined whether the switch Kp has been operated or not, and when the switch Kp has been operated, the latching relays XCI and XC2 are stored in the variable memory RAM and held.
The data indicating the status of the data is corrected.

In addition, a setting section FST is provided to set special conditions such as incoming call restrictions for each telephone device, and to send the output of this to the control section CNT, so that it can be set according to the setting situation. It is supposed to be controlled.

FIG. 2 is a specific circuit diagram of the transmission section SR, and the signal line L
Between the non-common side line of lll and the DC power supply +19V,
A resistor R11 with a low resistance value and a transistor Qlt as a switching element are inserted in series, and the control data DS1 from the control unit CNT is always "L#" (low level), and the output of the inverters IN, , is "H". ” (high level), the light emitting diode LD11 and the constant voltage diode zD11 are off, and the transistor QI+ maintains the on state due to the forward bias through the resistor R12, and the signal line Ll11 is connected through the fuse F1.
It supplies power to the

In contrast to the above, when the control data DS1 becomes "H" in a pulsed manner, the output of the 1 inverter IN,,,,,,.
Tonashi, light emitting diode LD1. and the constant voltage diode zD■ turns on, lowering the base voltage of the transistor Qll to the Zener voltage of the constant voltage diode ZD, . Accordingly, the collector-emitter resistance of the transistor Q1t increases, and the line voltage v1 decreases and the power supply becomes intermittent, and this is transmitted as a transmission signal, and this situation is reflected in the light emitting diode LD11.
Displayed by light emission.

Note that the diode I)tt is for clamping the voltage of the non-common side line to the Zener voltage of the constant voltage diode ZDl□ when the collector-emitter resistance of the transistor Qll increases.

On the other hand, resistor RIB~R13% capacitor CI+,
Transistor Q12 and diode D 12 r
When the receiving circuit is constituted by D13 and the transistor Ql+ is in the on state, when transmission is performed by changing the line impedance of the signal line LS1 in a pulse-like manner in the telephone rear end, the line impedance decreases. Accordingly, the terminal voltage of resistor 1ht increases, and the line side of resistor R11 becomes "L" in a pulsed manner, which causes capacitor C
1l as a forward bias to the base of transistor QI2, transistor Q12 turns on, and the collector current passes through resistor "14 + R15,"
The terminal voltage of the resistor RIS is applied to the control unit CNT as operation data DR1, and reception is thereby performed.

Note that the diode 012 is for protecting the transistor Q12, and the diode I)ts is for clamping the peak value of the operation data DR by the DC power supply +5V.

In addition, the control unit CNT monitors the presence or absence of errors in the operation data DR, by parity checking and matching of each byte, and when an error is detected, generates a reset signal R8T as “Hl” for a certain period of time, In order to change the output to "L", the transistor Q+t is turned off, the non-common side line is connected to the common potential via the diode DI+, and the power supply is completely cut off for a certain period of time.

For this reason, the circuit of the telephone rear end is reset 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.
The error condition is cleared.

As described above, the transmitter/receiver circuit SRC is a telephone postfix.

The same transmitting/receiving circuit S
RC2-8RC@ are provided for each signal line I42-Lag, and respond to control data DS2-DS, reset signals R8T2-R8T from the control unit CNT,
In addition to transmitting signals and resetting operations to the telephone stations 2 and 3, it also sends out operation data DR, to DR8 in response to transmission signals from the telephone stations 2 to 5.

The transmission and reception of signals to and from the telephone terminals 1 to 1 is carried out individually and sequentially under the control of the control unit CNT, and this is repeated at regular intervals.

Figure 3 (4) to (C) are circuit diagrams of the telephone post 1 to 3, where (4) is the communication system, ω) is the signal system, and (C) is the audible signal system. For convenience, the control unit CT is duplicated in ω) and ω).

Here, the line terminal T:1 connected to the communication line Li
．． 'If'r is connected to the telephone call circuit TKO via the hook switch H8I, diode bridge DB and dial circuit DIC, and when off-hook, the direct current loop is closed by the telephone call circuit TKO, and the loop current is The dial circuit DIC, which operates as a power source, allows dialing and telephone calls using the transmitter T and receiver R.

However, the dial circuit DIC is largely controlled by the light-receiving transistor of the photocoupler PC, and becomes operational only during a power outage of the commercial power supply AC.

In addition, a tone ringer TRG is connected to the line side of the diode bridge DB via a hook switch H8t, a capacitor C1゜1, and a resistor RIOI, and the power of this tone ringer TRG is connected in response to the arrival of a call signal. The system operates by generating a ring tone and applying it to the speaker SP via the transformer Tl0I and the contact p 1 t of the relay PF to drive it, as well as the contact p t O
and a transformer TI (12) connected in the same way via a capacitor 0102, which extracts the audio signal and passes it through a switch circuit s'w1ol and a potentiometer RVIOI to an amplifier MU 0103 and a contact p.
The speaker SP is driven through the IN.

On the other hand, signal 11i! Line terminal 'rst to which Lm is connected
.

A stabilizing circuit consisting of a transistor Q121, a resistor "1211", a capacitor C121*C122, and a constant voltage diode ZD121 is connected to TS2 via a diode D121 for blocking the application of reverse polarity and a blocking wire CH. The power supplied from 8U is stabilized to a local power supply of +12V, and then supplied to each necessary part, and the output is sent to the integrated stabilization circuit R.
The local power supply is further stabilized to +5V by EG, smoothed by capacitor C123, and then supplied to the necessary parts), which is similar to the control unit CNT with 8U in the main device,
The small-scale control unit CT is also operated by the local power supply +5V.

Note that the reset terminal R8T of the control unit CT has a resistor 11 connected in parallel with a diode D122 for rapid discharge.
22, the terminal voltage of the capacitor CH4 charged by the local power supply +5V is given through the resistor R123, and the delay in rising the terminal voltage of the capacitor C124 that occurs at the start of power supply is used as an "L" reset pulse. In response to this, the control section CT performs the above-mentioned reset and initialization.

In addition, between the line terminals TS1r and TS2, there is a capacitor Cl25 + C126) and resistors R124 to R129s.
Diode D123+D124s) Transistor Qxz
Himpata lN121N Input inversion type OR gate G
1□1, and NAND game) A receiving circuit using G122 is connected, and a diode D12! A transmission circuit consisting of an inverter XNl22, resistors R13° to R135, and transistors Q123 + G124 is connected between the connection point of the blockage line CH and the common circuit. The line voltage V corresponding to
The transistor Q122 turns on in response to the decrease in ,
If the terminal voltage of resistor R126 becomes "H" due to the flow of collector current, inverter I? The output of JIH is “L”
Turning to #, the electric charge of the capacitor C□26 that had been charged through the diode D124 is discharged through the resistor R127 and the output impedance of the inverter IN1□1, and the charge between the capacitor C1□6 and the resistor R127 is discharged. Depending on the time constant determined primarily by the value of capacitor 0126
Since the terminal voltage of the capacitor C126 decreases to "L#", the noise component is removed by this time constant, and the terminal voltage of the capacitor C126 is applied as "L" to one input of the OR gate (OR gate) 0121 via the resistor R12B. In response, the clip-float circuit (hereinafter referred to as FFC) FF consisting of the same gate G121 and NAND gate G122 is set, and the control data of "L#" is transferred to the port terminal pio of the control unit CT via the resistor R129. given to.

When the control unit CT confirms the control data, the control unit CT outputs the port terminal P.
6 to "L" and reset the FFC-FF, preparations are made to receive the next control data.

Also, depending on the operation data, the baud) P7 is pulsed to "Ll".
Then, the output of the inverter IN122 becomes "H#", which turns on the transistor Q123 and turns on the transistor Q124, so that the line terminal T811
Resistor: R15 via diode D121 between T82
s is connected, the line-to-line impedance between the signal lines I and s is reduced, and the transmission of the transmission signal is thereby strengthened.

As described above, the main device will be able to send and receive signals to and from 8U, but the hook switch US'' is connected to the boat terminal P8 of the control unit CT, and the output of the keyboard KB is connected to the input terminal KO~3. At the same time, the output terminal 80
~83 are connected to the scanning input of the keyboard KB via diodes 0151~DIS4, and the local power supply +5V is applied through the pull-up resistor r to each terminal P8゜KO which is set to "H". P8 in 3 becomes "L#" in response to the ON of the hook switch "H8" to detect off-hook, and output terminals SO to S3 are sequentially set to "L" at a predetermined period to perform scanning. It is checked whether 3 becomes "L#" at the input terminal KO~ in response to the dial keys * connected in a matrix.

Na, 1-9.0 and Kaede on speaker key, hold key KHq
It detects that the central line key KLI r KL2 is on, encodes the operation data according to these operation conditions, and then
In addition, a transistor Q151 is connected to the output terminal S4 via a resistor R151, and transistors 91sz to Q154 are connected to the output terminals S1 to S3 via a circuit of resistors R152 to 8157, respectively. is connected, keyboard KB
The output terminal S
4 to "L"', transistor 1; bsl is turned on, and when a local power supply +5V is applied to the light emitting diodes LD101 +LD102 corresponding to the central line key KLl + KL2 and the light emitting diode LD10B corresponding to the speaker key, the control data Output terminals 81 to S3 depending on
When is set to "L", the transistors Qlsg to Q154 are turned on, and the light emitting diodes LDIOI to LD103 emit light by energization through the resistors R158 to R□6o, and the diodes "Dlol + LD102" are continuously visible. Due to the light emission, the υ station line is reached.

The capture of L2 is indicated by similar intermittent light emission to indicate whether these are on hold or the like, and the same continuous light emission from the same diode LD103 indicates the reception and amplification state of the speaker SP.

On the other hand, depending on the control data, the boat terminal P5. Pi.

If PO is set to "Ll", the switch circuits S'%v, O, sw, .
The switching circuit consisting of G172 and resistors R171+R174 is driven, and transistor Q171 is also turned on by turning on transistor G1720, supplying local power supply +12V to amplifier A, and putting it into operation.

Also, inverter IN! ,, ~IN, 74, resistor R1
□5~R178 and capacitor C171+ Cl72
The oscillator 08CI01 +0801oz which generates tone signals of different frequencies is configured by 1, and the υNOR gate G is set by the "L" of the boat terminals P2 and P3.
When switch circuit 5w1o2 is on, the tone signal passes through them and also passes through input inversion type AND gate G173, and when switch circuit 5w1o2 is on, it is applied to amplifier A via resistors R179+R180. , the speaker power SP is driven by the low level, and the switch circuit SW
When l, , is on, it is applied to the amplifier ^ only through the resistor R179, and the high level drives the speaker SP.

In addition, depending on whether the switch circuit 5Wlo1 is turned on, the central office line ring tone sent from the main device KSU via the telephone line Lt, the ring tone from the door phone DRP, the voice ring tone, the received voice, etc. are emitted from the speaker sp. Switch circuit sw, o
2 or SW, 3 are turned on, and NOR gate G is turned on.
171 is turned on, the hold@second alarm sound, off-hook alarm sound, alarm sound corresponding to the alarm signal AL, etc. are emitted from the speaker SP.Similarly, when the NOR gate G172 is turned on, each of the keys in the keyboard KB is emitted. Touch tones when keys are operated, extension ringtones, etc. are emitted from the speaker SP, and NO
R gate G1□,.

If Glyz is turned on at the same time, a busy ringtone will be emitted as well.

However, the difference between each emitted sound is NOR game) G171
It is determined by changing the on/off period of +G172 and setting the intermittent status.

In order to connect to an external loudspeaker, the terminals M, G,
10 and - are pulled out to supply local power supply +12V through resistor R191, and resistor R11H+1□
When the output terminal S7 is set to "L#", the transistor Qsel is turned on, and the external loudspeaker is activated.

The output terminal S6 that maintains "H#" is connected to the input of the inverter IN175 while the local power supply +5V is being supplied, and the output of this is "L" when the commercial power supply AC is energized. The transistor Q192 is turned on through the circuit of the circuit R1941ml'as, and the diode D for surge absorption is turned on.
191 operates the relay PF connected in parallel, and the light emitting diode of the photocoupler PC is energized via the resistor RIIHI, and its light emission causes the photocoupler P
Turn on the light receiving transistor C, and turn on the dial circuit DIC.
operation is stopped.

In addition, depending on the operation of relay PF, contact pf O turns on,
When the contact point pft is in a state to select the output of the amplifier A, the switch circuits 5W1ol to SW. On the other hand, when relay PF is restored due to a power outage of commercial power supply AC, contact p is activated.
10 is off, contact pf! is in a state where it selects the output of the tone ringer TRG, and only in response to an incoming call from the directly connected station line Ll or L2 in the main unit KSU, the speaker SP is driven and the light emitting diode of the photocoupler PC is reduced. Dial circuit DIC according to the light
When the dial key on the keyboard KB is operated after going off-hook, a separate contact provided at the bottom turns on, and a dial signal using a pulse signal or a composite audio frequency signal is sent out. Even during a power outage, calls can be made and received via the central office line L1 or L2.

However, the dial circuit DIC,)-ringer TRG.

The relay PF and its peripheral circuits may be provided only in the power outage telephone.

FIG. 4 is a diagram showing the signal transmission situation between the main unit KSU and the telephone equipment. First, a polling signal PR is transmitted from 8U to the telephone equipment to the main equipment. Place the phone accordingly.

When a response signal X indicating operation data is transmitted from the main unit KSU, the main unit KSU responds to the reception of the response signal X indicating the operation data.

A control signal Y indicating control data is transmitted to the telephone, and these transmissions and receptions are sequentially carried out to the telephones 2 to 2, and the above transmission and reception is repeated at a fixed period t.

FIG. 5 is a waveform diagram showing in detail a series of polling signals PR to control signals Y, in which the line voltage vs of the transmission signal line from the main unit KSU decreases by v1, while the telephone equipment The line voltage vm of the transmission from the line is reduced by only v2.

Here, the polling signal PR is composed of a 3-bit pulse signal, and the response signal The data bits DO%D, which are composed of bytes X1 and X2, are coded according to the operation situation,
According to this, the insertion or non-insertion of the data pin (Do=Ds) is determined. For example, insertion indicates the logical value "1", non-insertion indicates the same "0#", and the first byte Even if the insertion or non-insertion of the daughter data bit Do=Ds is reversed between X1 and the second byte X2, and the codes indicated by each are the same, each pie) XI.

X2 are transmitted with mutually opposite phases.

In addition, the control signal Y includes a 2-bit start signal BT and a synchronous bit SY1 (data pin).Do-I)
s, bytes Y1 to Y3 consisting of parity bits PY, and a total of 21 data bits are defined as corresponding to control items, such as insertion,
In response to non-insertion, a logical value is indicated in the same manner as described above, and the control item is set to be executed in response to this logical value of "1".

Therefore, the codes in bytes XI and X2 indicate the operation data of the stuffing machine, and the data bits DQ#D in Yl to Y3 indicate the control data. Each data bit of bytes Y1 to Y3)
For example, the correspondence relationship with Do#D is that the control data is indicated by the data of Pi)Yl to Y3 corresponding to the control item and the bit DoND6, and in the control unit CT on the telephone side,
Control according to the control data can be performed by simply counting the order of each pie) Yl-Y3 and data bits Do-D and determining their states.The procedure for decoding the control data is simplified. will be realized.

Note that when decoding the control data, the start signal ST
Counting is performed using SY as a reference, and the presence or absence of an error is determined based on the parity bit PY.

In addition, in 8U to the main device, each received pie) XI
, X2 are made the same phase, and then it is determined whether or not each byte (Xl, It detects something and then responds accordingly.

However, the main device receives the above-mentioned received signal X at 8U.
If an error in
If the control signal Y cannot be received within a certain period of time after transmitting, it is determined that an error has occurred in the own transmitted signal,
When the bowling signal PR addressed to itself is received in the next period t, a response signal xt indicating the same operation data as the previous time is retransmitted in response.

FIG. 6 is a detailed diagram of the main part of FIG. 5, where the figure shows the boring signal PR, ω) shows the start signal ST, (C) shows the synchronization bit SY and the data bit Do%D2, and in (4) is the bit interval between the first bit Pl and the following bit P2 tr x 39μ8・cl Subsequent bits P2 and P
The bit interval with 3 is set to t 2 = 27 μsec,
In a3), the interval t3 between the first bit S1 and the succeeding bit 8z is set to 39 μsec, and in Q, the bit interval t between the synchronization bit SY and the data bit D.
4 is equal to the bit interval t5 of Do#D2, and t4 = t5 = 72 μsec.
Each bit interval tt + t2 + t3 of the boring signal PR and start signal ST is the data bit Do-w
The bit interval t6 of D, is set to be different from the bit interval t6 of the star) signal ST and the synchronization bit ST and the data bit DO#D.

The bit intervals and number of bits are common to the response signal X and the control signal Y.

Note that the parity bit PY is also a data bit D.

~D6 is added with the same bit interval ts.

FIG. 7 is a flowchart showing the transmission control by the 8U processor CPU in the main device. In order to wait for reception of signal X, set "transmission star and wait flag set" 1.
At the same time, since the processor CPU does not have an interrupt port terminal and uses a port terminal that is shared with data, the flag of the interrupt mask that does not handle interrupts is set to 1 in order to receive the interrupt. Reset by interrupt mask release #103, response signal ``''X reception completed by interrupt routine shown in 忤)?-111 is YE
If S, ``'X reception end flag reset'' 112
After that, perform the start signal "ST transmission" 121, and then transmit the periodic beep) SY and data bit Do.
Byte ″″ consisting of #D6 and parity bit PY
Perform Y1 to Y3 transmission' 122 and place the telephone 1
~ Place, end? While '123 is NO, step 101 and subsequent steps are repeated, and in response to step 123 being YES,
After performing control based on the contents of the response signal Y in the 'received data processing' 131, 1
When will the next polling start? '132 becomes YES, so for example 98. ．． Step 101 and subsequent steps are repeated with a period t of 1 msec.

In the interrupt routine of CB), the start signal in the response signal
Execution of this starts in response to SY, and in contrast to step 103, 1 interrupt mask #201 is performed by setting a flag to prevent the subsequent interrupt routine response, and then the flag in step 102 is checked and 1 transmission is performed. Waiting for the start?
= 202, and if this is YES, it is the reception order of the start signal 8T, so by the start signal "BT reception #211, the bit interval t3 with the subsequent bit 82 is clocked based on the detection time of the first bit S1. Detect by counting pulses, etc., and detect the number of these bits by counting. If the result matches ω) in Fig. 6, the start signal "8T OK?" “212 is YE
(S), after resetting the 1 transmission start wait flag #213 corresponding to step 102, the next synchronization signal is reset) In order to allow the response of the interrupt routine by SY, the 1 interrupt mask is released as in step 103. 214
Do this.

Then, when the synchronization bit SY arrives, step 2 is performed again.
01 and step 202 are repeated, this time the flag is reset by step 213, and step 2
02 is determined to be the reception order of SY for NO, and by data reception #221, each bit of SY) is detected based on the detection time of SY) Byte ``''Xi, X2 Finished receiving? ``222 ONO and 1 interrupt mask release similar to step 214'' 223, step 2 is executed according to the synchronization bit SY of byte X2.
01 and subsequent steps are repeated, and if step 222 is YES, the "receiving path" corresponding to step 112 is completed.
“Do 231.

Nao, @RET,” corresponds to step 111 ONO,
"RET2" corresponds to YES in step 111)
, check the flag in step 231 and proceed to step 11
1 becomes YES.

FIG. 8 is a flowchart of transmission control by the processor provided in the control unit CT of the telephone device, where ■ indicates the main routine,
), polling signal @PR wait flag/cera)
” 301, perform 1 interrupt mask release = 302 in the same way as step 103 to set the reception standby state, and if 303 is YES, polling signal @PR reception finished?, start signal @BT transmission” 311 and bivi Xi , X2 transmission ``312'' is performed, 1 interrupt mask release #314 is performed again to enter the reception standby state, and the control signal ``''
Y reception finished? In response to '321 becoming YES, the 1 reception end flag is reset (322), 'reception data processing #323 performs control based on the control data, and steps 301 and subsequent steps are repeated.

On the other hand, in ω), each leading bit of the polling signal PR or start signal ST, or the synchronization bit S
Y starts execution of the interrupt routine, step 2
After performing 1 interrupt mask #4o1 as in 01, check the 7 lag in step 301 and send the polling signal.
Waiting for PR? "402 determines that the reception order is YES, and polling signal @PR reception" 411 causes the subsequent bit P21 to be detected based on the detection time of the first bit P1.
The bit interval '11t2 of Ps and the number of these bits are detected in the same way as steps 211 and 212, and if they match with FIG. 6(4), the polling signal ""PR-
OK? "412 is YES, polling signal @PR wait flag reset 1413 corresponding to step 301
Do the following.

Note that while step 412 is NO, 1 interrupt mask is canceled.
Step 4 (H and subsequent steps) is repeated via step 414.

Also, 'RET3' corresponds to step 303 ONO,
'RET4' corresponds to YES in step 303, and the flag in step 413 is checked and step 303 becomes YES.

Next, when the start signal ST arrives, step 40
1 and NO in 402, it is confirmed that the start signal ST is received in accordance with the flag in step 313. ``421 YES'' is judged, start signal @ST received ``431'' and ``ST OK?'''
432 is performed in the same manner as steps 211 and 212, and if step 432 is YES, the @ST waiting flag set 433 corresponding to step 313 is performed, and
'Perform interrupt mask release n434.

Note that "RET6" corresponds to NO in step 321,
While step 432 is NO, steps 401 to 43
2ONO and repeat step 434.

Next, when the synchronization pi) SY of pi) Yl arrives, 1 data reception "441" and bytes "" Y1 to Y3 are received through steps 401, 402 and 421.
Finished receiving? '442 is performed in the same manner as steps 431 and 432, and if step 442 is YES, 1 reception end flag set corresponding to step 322'443
However, while step 442 is NO, step 401 and subsequent steps are repeated via 1-interrupt mask release #444.

Note that "RgT," corresponds to YES in step 321, and in response to the flag in step 443, step 321 is YES.
It becomes S.

Therefore, the main unit KSU and telephone units 1 to 8
When it becomes the receiving side, polling signal PR, start signal ST and pi)XI,
X2. The reception order of Yl to Y3 is determined, and execution of the interrupt routine is started by detecting each leading bit of the polling signal PR and start signal ST as well as the synchronization bit sy, and the bit interval i is determined based on each leading bit.
1 + tz + t3 and the number of bits are detected, and based on these, the polling signal PR, start signal BT, and synchronization pin (SY) are determined. data bits Do-D and data bits Do-D, the possibility of misidentifying data bits D and #D as each signal PR,, BT or SY (synchronous bits) is eliminated, and data bits D and D
This prevents errors from occurring in reception of signals o to D6.

However, the number of bits and bit interval of each signal PR, ST need only be different from the number of bits and bit interval of data bits Do-D, and can be arbitrarily selected depending on the conditions.
The synchronization bit SY can also be a similar plurality of bits, and the same effect can be obtained even if the order of the response signal X and control signal Y in FIG. 5 is switched.

Note that the signal lines Lllll to Lll11 may be made common, and an address code for each telephone set may be added to the polling signal PR, and the configuration of each signal X and Y may be determined according to the conditions. , it is also optional to transmit the control data in the same format as the transmission of the operation data.

Furthermore, the pulse signal shown in FIG. 5 not only reduces the line voltage vlI but also reduces the line voltage v! Various modifications are possible, such as increasing or intermittent I, modulating an alternating current signal and superimposing it on the power supply, or supplying the power by entirely separate lines.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, there is no confusion between each transmission control signal and data bit.

This prevents the data bits from being misidentified as transmission control signals during reception, thereby ensuring accurate and reliable reception of the data bits, which provides a remarkable effect in various button telephone devices.

[Brief explanation of the drawing]

The figures show an embodiment of the present invention, in which Fig. 1 is a block diagram of the main device, Fig. 2 is a circuit diagram of the transmission section in Fig. 1, Fig. 3 is a circuit diagram of a telephone, and Fig. 4 is a signal transmission diagram. Figure 5 is a diagram showing the waveform of the transmission signal, Figure 6 is a detailed view of the main part of Figure 5, Figure 7 is a 7p-chart showing the transmission control status by the processor of the main device, Figure 8 is a diagram showing the transmission control status by the processor of the main device. The figure is a flowchart showing the transmission control situation by the processor of the telephone. KSU...Main unit, L81~LII8...Signal line, place, ~ place,...telephone (button telephone)
, CNT, CT, --, control unit, CPU--, -processor, SR...transmission unit, R11NR15r R1!
1~R135・Resistor, C11・−・Capacitor, Qll r Q12 + Q1211 + Qxz
a Transistor 11N122...Inverter, PR...e 7f? -Link signal, X・φ
...Response signal, YΦ...Control signal, g'l" a a
*a start signal, SY 11 @ 11 e synchronization bit, D6""06 * skewer e data bit, P
l, Sl...First bit, R21-R3182.0
・Fist subsequent bit, F""! 5...Bit interval. Patent applicant: Tamura Electric Manufacturing Co., Ltd. Agent: Masaki Yamakawa (l'! or two people) Figure 6 SI S2

Claims (1)

[Claims] In a signal transmission method for a button telephone device in which various transmission control signals and data bits are serially transmitted between the main device and the button telephone according to a predetermined order, the transmission side transmits each of the transmission control signals to the data bits. Transmitted as a signal consisting of multiple bits with different bit intervals,
On the receiving side, the first bit of each of the transmission control signals is detected according to the order, the bit interval with the subsequent bit is detected, and the type of each transmission control signal is determined based on the order and the bit interval. A signal transmission method for a button telephone device characterized by: