JPS6055793A - Signal transmission and reception control system for key telephone system - Google Patents

Abstract

PURPOSE:To decrease the number of parts by transmitting the start signal from a master device in a prescribed cycle and therefore eliminating the need to add an address code to each telephone set. CONSTITUTION:The multiple connection is secured via a common signal line LS between a main device KSU and telephone sets ST1-ST4 respectively. At the same time, these telephone sets are connected individually to the device KSU via private lines L1-L4. Then start signal transmission circuits SS1-SS4 provided within the device KSU transmit start signals successively with superposition to the lines L1-L4 in a prescribed cycle respectively. While each of the ST1-ST4 performs transmission of signals to the device KSU by a transmission circuit SC and a reception circuit RC in the device KSU in response to the detection of the start signal. In such a way, the addition of an address code is eliminated to each telephone set. This can reduce the number of component parts.

Description

Detailed Description of the Invention [Technical Field of the Invention] The present invention relates to a button telephone device comprising a main device and a plurality of key telephones (hereinafter referred to as telephones), in which control signals are transmitted between the main device and each telephone. Contains information on methods for controlling transmission and reception operations.

[Prior art]

In general, in electronic key telephone devices, the main device and each telephone are connected via a common signal line, and polling (No. 1 Only when each phone detects its own address code (t), signals are sent and received from the main device. A large number of address mode setting means such as head dip switches must be provided, and the increase in the number of parts creates a drawback that becomes an obstacle to reducing the cost of the device.

[Summary of the invention]

The present invention has the purpose of fundamentally solving the drawbacks of the conventional system. It is connected to each phone using a dedicated line, and from the Osou @, it is transmitted to each dedicated line individually and sequentially to the start toy No. 8 in a predetermined cycle, superimposed and transmitted, and each phone detects the start signal. Accordingly, the present invention provides an extremely effective signal transmission/reception control system for a button telephone device in which signals are transmitted and received with the main device for each telephone.

EXAMPLES] V, below, the present invention will be explained in detail with reference to figures showing examples.

The k-th diagram is a block diagram of the entire configuration. Between the main unit KSU and the telephone ST+-Sr1, there is a common signal line L.
It is connected in multiple ways by s, and the telephone [%ST+
~ST4 and the corresponding dedicated ftj3Ll~L4 are individually connected to each other, and the main unit KSU is connected to the receiving port 1i! which is connected to the signal line Ls! 8RC and a transmitting circuit 8C are provided and 6υ are used to transmit and receive signals to and from the telephones STs to ST4, while a start signal transmitting circuit SS+ = SS* is connected to each dedicated line L+ -R4. , the start signal is superimposed on other signals, voltage, current, etc., and then transmitted.

The main unit KSU is provided with a control unit CNT consisting of a processor such as a microprocessor and a memory, etc. Under the control of this unit, each circuit operates, and the start signal is transmitted to the dedicated lines L1 to L4. The signal line Ls
Control signals are transmitted and received by each of the telephones ST+ to ST4.

Fig. 2 is a specific circuit diagram of each circuit in the earthen fiKsU, Fig. 3 is a circuit diagram of the portion corresponding to Fig. 2 in the telephone ST+-Sr1, and Fig. 4 is the transmission of start signals and control signals. This is a timing chart showing the situation, and in this example, telephones STI to ST4 are used as the signal line Ls.
Using the positive terminal side of the power supply line that supplies DC power to
Similar negative electrodes l1111k are used as 1 to L4.

That is, in FIG. 2, the power supply +24VKfi, the transistor Q+ t, the resistor R+, and the resistor R+ inserted in series.
It is turned on by the forward bias by R2, and it is applied to the signal line L8 via the short-circuit protection resistor R3.
When transmitting a signal, Kld, control unit C
Since the NT's transmitting baud) Ps becomes low level in a pulse-like manner according to the transmitting code, the resistor R4'I;r
, the input of the inverter INV+ which was kept at -11" (high level) and one input of the input inverting type AND gate) Gt is %Ln.
The output of the gate G+ changes to 'II', which is connected to the resistor R.
The voltage is divided by y and Rs and marked 7111 to the base of the transistor Q2, turning on the transistor Q2', and connecting it to the transistor Ql via the constant voltage diode)'ZD+k.
By connecting the base of transistor Q1 to the negative terminal side, the collector-emitter resistance of transistor Q1 increases, and the signal line L
The voltage of s drops by about 5V as shown in FIG.

Note that this reduced voltage is caused by the constant voltage diode ZD.

The output of the inverter INVI is determined according to the Zener voltage of the transmission boat Ps, and the output of the inverter INVI is
In order to charge the capacitor C+k through the resistor Rsk, the terminal voltage of the capacitor C1 rises according to a time constant determined by the values of both, and this causes the voltage at the folding resistor R to rise.
When given as sH'' to the other input of AND gate G1 through Q'C, the output of AND gate G+ becomes % L r
J (7) By turning off the transistor Q2, 1. The time width of the voltage drop is determined according to the values of the resistor R5 and the capacitor C1, and this is transmitted as a signal.

In addition, the signals similarly transmitted from the telephones ST1 to ST are applied as ◆L11 through the capacitor C2'fc to the base of the transistor Q3, which is kept at the same potential as the emitter by the resistor R9, and the transistor ( In order to turn on bk, a collector current passes through resistors R+o and Rh, and the terminal voltage of resistor U+t is applied as 1Hn to the power of inverter INV2.

Then, the output of inverter I NV2 becomes ◆L“,
Apply this to one input of the input inversion type OR gate G2,
Since the output of the same gate G2 is set as ri('', this is N
AND baud) is applied to one input of G3, and the other input is also set to 'H'' by applying +5v through the resistor Rate.
As a result, the output of the same gate G3 is 'L'
This is then given as a reception output to the interrupt port (INT) of the control unit CNT.

Note that the output of NAND gate G3 is returned to the other input of OR gate G2. If the output of NAND gate Gs becomes "L", the other input of OR gate G2 also becomes
Is the output of the inverter INV "L"? In order to maintain the output of the Olmo gate G2 at "11" even if it returns to H'', the output of the NAND gate G3 is held at the state of "SL", and the control unit CNT confirms this and then resets the reset boat Ps f 'L. ”, and the output of the AND gate G2 is set to @Hu to reset the holding state, and the interrupt port INT is kept at ``L''.

However, the 1fi1111 part CN'l' is the transmission port P.
While sending a 1L" pulse from s, interrupt baud) INT's SL" is ignored, and when the receiving state is reached in response to the end of transmission, the reset port P*'e'L" is set to the west, and the above reset operation is performed. It is something that must be done.

The diode D1 has a large capacity capacitor inserted between the signal line L8 and the dedicated line Lt-L4 on the telephone ST+ to ST4 side, and this affects the waveform when the voltage drops. The purpose is to discharge the surplus charge of the capacitor and make the waveform fall steeply when the voltage drops. The diode D3 is used to bypass the voltage and prevent damage to the resistor Q3.The diode D3 is used to clamp the input of the inverter INV2 to -15V when it is turned on by the positive direction noise component.

On the other hand, +5V is applied to each input of the inverters INV, +~INV, whose outputs are connected to each of the dedicated lines L□~L4 through the resistors R+3~ζ+ek, respectively. , the output is always set to '(r'L'), and the output impedance is set to 1 to connect the dedicated lines L1 to L4 to the negative pole side. When the output becomes 1L'', the output of the inverter NV3 to INV changes to !H'' accordingly.
In order to set the voltage of the dedicated line L1''-L4 to approximately +l O''V, the line voltage between the signal line Ls and the signal line Ls in Fig. 4 is approximately 1
The voltage drops by 4V, and this is transmitted as the start signal SB+ -Sn2.

In addition, to ensure detection, the start signals SBI~S B < are multiplied by M as a voltage change with a longer width and larger width than the control signal, but if the waveform of this becomes steep, click noise [ To prevent this, a series circuit consisting of resistors Ray~R2° and capacitors 03~clt is connected between the outputs of the inverters NVs~INVi+ and the negative electrode side, respectively. The waveform of start No. 43 SB+ to SB4 has a slow fall and a slow rise.

Start number 18 5Bl-Sn2 is connected to each dedicated line L.
Since superposition is performed for each I-L4, between the signal line Ls and the exclusive line L+, similarly between L8 (!: L2, between Ls and Ls, and between Ls and L4,
Start signal SB
r is only detected by the phone ST+ and similarly SBz
Ore ST2 is detected only, Sn2 is detected only by ST3, and Sn2 is detected only by ST4.

In FIG. 3, u, (, receives power supply through the blockage line CH!11 inserted into the W line L8, the reverse voltage blocking diode D31 inserted into the dedicated line, and the capacitor C31k, After stabilizing the power supply part PS, blocking wire CH32 and capacitors C32 and C3s
It is supplied to each part as +5V through '
R34, transistor Q31% inverter INV3.
and a receiving circuit with each gate G31 and G32, an inverter INVs+, and resistors R35 to Ra8.
, an AND gate G37, and a transmission circuit 9 consisting of a transistor Q32, which are controlled by a control section CNTs similar to the control section CNT of FIG.

The operation of each circuit and the control status of the control unit CNTs are the same as those shown in FIG.
When the NTs detect it, it enters the receiving state, and upon completion of reception, it shifts to the transmitting state.

Also, during transmission, transistor Q32 is turned on,
The surplus IErN is passed from the signal line L8 to the resistor R31+, and its voltage is lowered by about 5V.

Therefore, from Figure 4 to η, signal line L3 - private line L1
Similarly to 1, each voltage change between Ls-Lx, Lm-L3, and LsL4 is shown.
After sequentially and repeatedly superimposing B+=8B4, the signals 5DKI to SDK from the main unit KsU,
When the start signal SB, ~5R4f) is detected, the telephone a STt ~8T4 enters the receiving state,
After receiving signals 5DKI to SDI individually, the telephone ST
r~ST4 transmits signals SDa+~5Ds4 to each individual, and 8U is sent to the main device for each telephone STI~ST4.
The transmission and reception of signals is repeated.

FIG. 5 (5) is a flowchart of the control operation by the control unit CNT, FIG. L" and %h "'H' After transmitting the rotation start signal SBI k, perform 1 damage processing and 1 reception processing", and perform the same control as the transmission boat %P4 = L
'' and 'P4'', ``H'', 1 transmission process'' and 1 reception process H1, and this is repeated.

On the other hand, in (J3), is the start signal ISB detected? If "'" is YES, the "call/receive processing" and "1 transmission processing" are performed, and this is repeated.

Therefore, polling for telephones S1'1 to ST4 can be done by transmitting start numbers SBI to 'SBA', eliminating the need to add an address code, etc., and eliminating the need to provide a switch for setting an address code. , the equipment cost can be reduced by reducing the number of parts.

In addition, the power supply line is generally connected to the telephone ST with positive and negative poles as a pair.
Since wiring is done for each I to ST4, if one pole side of the power supply line is used as a dedicated line L This is preferable because it achieves this.

However, the start signals SBI to SB4 may be not only a drop in voltage but also changes such as instantaneous interruption or increase in voltage, and may also be a switching signal of a specific frequency.
As long as L4 is individually wired, it is possible to use a communication line or a single line such as a signal line dedicated to transmitting control signals.The circuit configuration should be adjusted according to these requirements. In addition, the number of telephones ST+ to ST4 may be arbitrarily determined. In FIG. 5, one transmission process "
It is up to the user to make various modifications, such as interchanging the steps of ``reception processing'' and ◆reception processing''.

〔Effect of the invention〕

As is clear from the above explanation, according to the present invention, when polling each telephone, there is no need to add an address code, the need for a switch for setting the address code, etc. is eliminated, and the number of parts is reduced. As a result, the structure can be simplified and the cost of the device can be reduced, resulting in significant effects in various key telephone devices.

[Brief explanation of drawings]

The figures show an embodiment of the present invention, with FIG. 1 being a block diagram of the entire configuration, FIG. 2 being a specific circuit diagram of the main device, and FIG. FIG. 4 is a timing chart showing the transmission status of each signal, and FIG. 5 is a 70-chart showing the control operation of the control unit. KSU...Main device, STt = ST4・Exposure...
Telephone (key telephone), Ls...signal line, L+
~L4 ""@"Dedicated line, CNT, CNTs...
...Control unit, RC--Reception circuit, SC--Transmission 1
B circuit, SS1 to 884 φ...Start signal transmission IB
Circuit, Q1~Qs + Q31 + Q32...Φ
Transistor, INVI ~ INVs, INV3
1, rNVsx --- Inverter, (x I*
Gss ” ” ・AND gate, Gz r Gs
+ @ fist ・-OR gate, Gs lG32 ” '
” ” NAND gate, Rt ~ Rzo, Rsl
~nss...Resistor, C+-C^, Cs1-
Cs5... Capacitor, zDI... Constant voltage diode. Patent applicant: Tamura Electric Co., Ltd. Agent Masaki Yamakawa (and one other person)

Claims (1)

[Claims] A main device and a plurality of key telephones are connected in multiple ways by a common signal line, and each of the key telephones is connected to the main device using the signal line according to the order specified by the main device. Button 1 to send and receive signals sequentially! In the telephone device, a dedicated line corresponding to each of the key telephones is individually connected between the main device and each of the key telephones, and a start signal is sequentially sent to each dedicated line at a predetermined period. and providing means for superimposing the start signal on the main device, and providing means for detecting the start signal on each of the button telephones, and transmitting and receiving signals to and from the main device for each button telephone in response to the detection of the start signal. t- Signal transmission and reception control system for button telephone equipment.