GB2029165A - Switching equipment for a key-controlled intercom or public address system - Google Patents
Switching equipment for a key-controlled intercom or public address system Download PDFInfo
- Publication number
- GB2029165A GB2029165A GB7928665A GB7928665A GB2029165A GB 2029165 A GB2029165 A GB 2029165A GB 7928665 A GB7928665 A GB 7928665A GB 7928665 A GB7928665 A GB 7928665A GB 2029165 A GB2029165 A GB 2029165A
- Authority
- GB
- United Kingdom
- Prior art keywords
- connection
- switching
- units
- switching equipment
- input
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04M—TELEPHONIC COMMUNICATION
- H04M9/00—Arrangements for interconnection not involving centralised switching
- H04M9/002—Arrangements for interconnection not involving centralised switching with subscriber controlled access to a line, i.e. key telephone systems
- H04M9/005—Arrangements for interconnection not involving centralised switching with subscriber controlled access to a line, i.e. key telephone systems with subscriber controlled access to an exchange line
- H04M9/007—Arrangements for interconnection not involving centralised switching with subscriber controlled access to a line, i.e. key telephone systems with subscriber controlled access to an exchange line wherein the key telephone sets are star-connected to a central unit by a limited number of lines
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- Engineering & Computer Science (AREA)
- Signal Processing (AREA)
- Interconnected Communication Systems, Intercoms, And Interphones (AREA)
- Telephonic Communication Services (AREA)
Abstract
Switching equipment for a key- controlled simplex or duplex intercom or public address system in which the interconnection of the line paths L and connection paths S is effected automatically through a switching unit including a programme controlled microcomputer connected through input-output units EA to the line circuits 6 and connection circuits S arranged on three types of modular units; one or more "linear units" by which each line L is connected to one of the input-output units EA; one or more "connection units" upon which for each predetermined possibility of connection there is an electronically controllable switching device S the control input to which is connected to one input-output unit EA; and one or more "call station units" upon which a transformer U is arranged for each user station the primary winding I of which is connected to a user station Sp and the secondary winding II of which can be connected through the switching devices to the secondary winding of other transformers. <IMAGE>
Description
SPECIFICATION
Switching equipment for a key-controlled intercom or public address system
This invention relates to switching equipment for a key-controlled simplex or duplex intercom system or public address system having line selection, in which each user station can be connected to a predetermined number of other user stations and in which the interconnection of the line paths and connection paths is effected automatically through an exchange so that by the interconnection the amplifiers of the user stations connected together are switched on and engaged signals are fed to the user stations remaining at the time.
Such a switching arrangement for a keycontrolled simplex or duplex intercom system or public address system is described for example in West German Patent specification
A/S 2434321.
A disadvantage of known simplex intercom systems having line selection consists in the high outlay on wiring for the exchange, in particular when there is a large number of call stations and a large number of connections between the individual call stations are required, particularly for ensuring connection of everyone to everyone In particular with n call stations, to ensure connections of "everyone to everyone" there must exist n(n-1) 2 connection circuits and n(n - 1) line paths, and the outlay on circuits and wiring in such exchange increases very rapidly. Thus for 1 6 call stations 1 20 connection circuits and 240 line paths are necessary to meet this requirement.There exists a need for systems having a far greater number of call stations, for example in railway traffic, so that even when not every call station needs to be connected to every other call station, the outlay on circuits and wiring remains very great.
With known systems it is for example usual to arrange the connection devices for the call stations on special individual modular units.
Depending upon the structural design the connection electronics and the line transformers for one or a maximum of two call stations are then accommodated on one modular unit. For the electronic interconnection of the connections so-called connection modular units are employed. Such a connection modular unit is equipped with two independent sets of connections. Depending upon the size of the whole system there is then a large number of call station modular units and connection modular units which are arranged to be able to be plugged into racks, to be accommodated in the exchange. The racks are received by frameworks, and there is added to the construction of the exchange the internal wiring of the frames, so that the exchange as a whole after the connection of the external cabling can perform the required interconnections of the connections.
It is known for systems having code selection, for example in call communication, of using computer-controlled switching systems, as for example described in "Nachrichten
Elektronik" No. 5, 1978, pages 145 to 149.
In this instance microprocessors (microcomputers) under programmed control are employed, by which the interconnection of the connections is controlled.
The invention is based on using the control by microprocessors under programmed control for a switching equipment of the kind initially described, in order to reduce considerably the outlay on wiring which in the particular case of a simplex or duplex intercom system or a public address system having line selection is particularly high and to obtain a clear and easily expandable construction of such a central switching equipment.
By the utilization of the invention the overall construction of the simplex or duplex intercom system or public address system does not need to be altered. In particular the construction of the call stations and the connection of the call station to the exchange can be effected in the same way as in known systems of this kind. Merely in the exchange itself is simplification in the circuit construction and outlay on wiring achieved, so that any conventional call stations can be connected to a switching equipment which is controlled by microprocessors under programmed control and in the case of an existing system the exchange can be re-equipped.
The invention provides switching equipment for a key-controlled simplex or duplex intercom system or public address system having line selection, in which each user station can be connected to a predetermined number of other user stations and in which the interconnection of the line paths and connection is effected automatically through an exchange so that by the interconnection the amplifiers of the user stations connected together are switched on and engaged signals are fed to the user stations remaining at the time, characterized in that in the said exchange a microcomputer is provided which through input-output units which receive and emit d.c. voltage signals, is connected to the line and connection circuits in the exchange which are arranged on three types of modular units separate one from another, at least one said modular unit being provided of each of the following types, namely
(a) a linear modular unit upon which a coupling circuit is arranged through which each line is connected in a d.c. mode to one of the input-output units;
(b) a connection modular unit upon which for each predetermined possibility of connection an electronically controllable connection switching contrivance is arranged the control input to which is connected to one of the input-output units; and
(c) a call station modular unit upon which for each user station a transformer is arranged the primary winding of which is connected in each instance to a user station whilst a central tapping on the primary winding can be connected through one of the input-output units to a source of voltage and the secondary winding of which is connectable by means of a predetermined selection of the said electronically controllable connection switching contrivance in each instance to the secondary winding of the other selected transformers; and that the interconnection of the line paths and connection paths is effected under programmed control signals from the microcomputer.
An essential feature of the switching equipment in accordance with the invention is the dividing up of the modular units which may for example be constructed in known manner as insert cards, into three types fundamentally different one from another. Each modular unit has a certain number of inputs and outputs respectively and is controlled on its own by one of the input-output units. The calling and voice connections are respectively interconnected at the same time by the microcomputer, the programme of which is so constructed that the whole of the necessary switching functions are triggered at the correct moment. The outlay on wiring of the exchange necessary with known systems lies in the programme of the microcomputer.
Thus the feature in accordance with the invention reduces not merely the outlay for internal wiring of frames in the exchange by the employment of a microcomputer, but it creates an exchange constructed in a completely different manner which requires relatively few modular units. For alterations in the operation of the intercom system and for expansion by addition of further call stations, and in many instances for the corresponding expansion of the exchange, a correspondingly modified programme for the microcomputer is sufficient.
The construction and programming of the microcomputer as well as the construction if the input-output units can moreover the carried out in known manner.
Advantageous features of the switching equipment in accordance with the invention are as follows.
Preferably on each modular unit the circuits are arranged which are associated in each instance with a plurality of lines or connections or call stations. Each modular unit may be designed for a predetermined maximum number of line or connection circuits associated with the particular type of modular unit.
This maximum number depends on the standardised size of the modular units, for example of the insert cards. Thus for example for the line modular units it has proved that with the employment of known standardised insert cards the coupling circuits, for example d.c.
termination sets for a maximum of 35 lines may be accommodated on one insert card.
With the employment of the same insert cards for connection, modular units up to 1 28 connection switching contrivances can be accommodated on one insert card and with the employment of insert cards for the call station modular units, one insert card accepts the transformers and other parts of the circuit for up to 20 call stations.
This means that for example with a system having 1 6 call stations of which any one is to come to be connected to any other, seven line modular units, one connection modular unit and one call station modular unit are necessary.
If not every call station is to be connected to every other the number of lines and connection switching contrivances is correspondingly reduced. The connection switching contrivances are preferably interconnected in such a way that they form one or more interconnection matrices, where one interconnection point of one matrix is associated with each connection switching contrivance. Since in most practical cases not every call station has to be connected to every other call station in the system, with the arrangement of the connection switching contrivances in one single interconnection matrix, many interconnection points would have to remain unused.It is therefore advantageous to arrange the connection switching contrivances on the connection
modular units in a particularly suitable way in separate groups, e.g. in the case of 1 28 connections four groups of 32 connections each. Then
in each instance certain groups may be interconnected together again in cascade. In this way even with relatively large systems, only a few connection modular units are necessary.
With intercom systems having line selection
and a central switching equipment, it is often
required to carry out certain special functions,
e.g. collective calls, priority switchings and call
storage. In known switching exchanges special
functions of that kind are realised by special
modular units which are partially additionally
necessary. In the case of the switching equip
ment in accordance with the invention many
of these special functions can be executed
merely through the programme of the micro
computer so that the number of special modu
lar units needed is also reduced.
One embodiment of switching equipment in
accordance with the invention is hereinafter
described and illustrated in the accompanying
drawings, of which
Figure 1 is a block diagram of one example of switching equipment according to the invention,
Figure 2 shows in greater detail the construction of switching equipment for four call stations, and
Figure 3 is a detail of the construction of a line modular unit.
Fig. 1 shows the fundamental construction of the central switching equipment of a simplex or duplex intercom system or public address system, wherein there are n call stations and m lines.
The switching equipment contains a microprocessor (microcomputer) CPU under programmed control having a working storage
RAM and a programme storage ROM. The input-output units designated here together by
EA are connected to the microprocessor
CPU-ROM-RAM in known manner through
BUS-leads. The number of these input-output units which are required depends upon the construction of the processor used, the inputoutput units used, and the size of the system.
The input-output units EA have groups of inputs and outputs. In Fig. 1 for the sake of clarity, the individual groups of inputs and outputs are symbolized by one output or input-output respectively. Thus for each of the lines L1 to Lm there is an individual inputoutput EAL in the input-output unit EA.
Moreover for each connection switching contrivance there is an individual output AV and furthermore for each call station, one output
ASp.
To the input-outputs EAL are connected the line modular units LK upon which there are the coupling circuits for the lines L1 to Lm, which are explained in greater detail hereinafter.
To the outputs AV are connected the connection modular units VK upon which there are the connection switching contrivances, and to the outputs ASp are connected the call station modular units SpK, which are connected on one side to the call stations Ap1 and
Spn and on the other side, through a group of connections symbolized by VS, to the connection switching contrivance on the connection modular units VK.
Fig. 2 illustrates switching equipment for a system having only four call stations, with the aid of which the method of operation of the switching equipment is as follows. It may be assumed that any of the four call stations is able to be connected to any other. This means that there are altogether 1 2 lines L1 to L1 2 and six connection switching contrivances S12 and S34. This construction needs one line modular unit LK, one connection modular unit VK and one call station modular unit
SpK. In Fig. 2 in addition to the modular units the input-output unit EA is indicated.
On the line modular unit LK there are in the embodiment illustrated, twelve termination sets G which for example may be constructed in the manner illustrated in Fig. 3. By these termination sets the operating voltage of the lines of 60V is converted to the operating voltage of the input-output unit of 5V and the ringing tone signals and engaged signals issuing from each of the lines and fed to each of the lines are distributed to the separate inputs and outputs EAL of the input-output unit EA.
On the connection modular unit VK, six connection switching contrivances are arranged and which are advantageously constraucted as integrated semiconductor circuits, where the control inputs to the connection switching contrivances S12, S13, S14, S23, S24,
S34 obtain the control signals through amplifiers P1 from corresponding outputs AV from the input-output unit EA.
On the connection modular unit SpK four transformers O1, Ü2, ij3, U4 are arranged.
The primary windings I of the transformers are connected through voice leads a-b to the call stations Spl, Sp2, Sp3 and Sp4. A central tapping on the primary winding of the transformers U 1 to U4 is in each instance connected through an amplifier P2 to one output
ASp from the input-output unit EA.
The secondary winding II of the transformers Ü1 to Ü2 is, in each case connected by one end to earth, whilst the other ends are connected to the connection switching contrivances on the modular unit VK, by which the connection of the secondary winding of the transformer may be effected to the secondary windings of the respective three other transformers.
The method of operation of the switching equipment is as follows.
The line inputs EAL (EL in Fig. 3) are scanned continuously by the microprocessor
CPU through the BUS-system for the most
recent state. The scanned states are compared with the state formed in the working storage
RAM. The state at the line inputs alters when a line key is actuated, for example when the
call station 1 calls the call station 4 and the
calling signal is fed through the line L1 and the corresponding termination set G to the associated input EAL. Because of the entering
alteration in state, the microprocessor CPU
reads from a connection table contained in the
programme the present output configuration
for the line outputs EAL (EL in Fig. 3),
connection outputs AV and call station out
puts ASp. The new output configuration is
communicated to the input-output units EA
through the internal BUS-system.In the exam
ple specified this ensures that the connection
switching contrivance S14 is simultaneously
connected through, and a supply voltage of
60V is fed from the outputs ASp to, the
primary windings I of the transformers U1 and Ü4 through amplifiers P2. Voice communica
tion is thereby produced between the call
stations Spl and Sp4. Moreover through the corresponding outputs EAL and the lines associated with these the engaged signals are fed to the remaining call stations. The internal image of the line inputs is then brought to the latest state by the microprocessor CPU.
The course described is followed after each alteration established upon actuation of a line key. As long as no alteration occurs, the line inputs are indeed continuously scanned but the outputs are not affected. Upon letting go the line key after completion of the message, voice communication between the call stations Spl and Sp4 is interrupted again, controlled by the microprocessor.
During the connection between the call stations Spl and Sp3 a similar voice communication can be built up between the call stations
Sp2 and Sp3.
The course of operation of a call station by a switching equipment controlled by a microprocessor is thus the same as in known systems.
The method of operation of the d.c. termination set G illustrated in Fig. 3, which serves as a coupling circuit in each instance between one of the lines L1 to L1 2 and the corresponding input EL or output AL of the input-output unit EA is as follows.
A calling signal, for example issuing from the line L1, is fed through a transistor T1 and a further transistor T2 to the input EL, whereby it is converted from 60V to 5V. A signal approaching from the output AL runs through the transistors T3 and T4, by which it is converted from 5V or 60V and arrives finally through the diode D on the line Li. At the same time the branch of the termination set leading to the input EL is short-circuited by a transistor T5 so that the signal coming from the output AL cannot return to the input EL.
Claims (11)
1. Switching equipment for a key-controlled simplex or duplex intercom system or public address system having line selection, in which each user station can be connected to a predetermined number of other user stations and in which the interconnection of the line paths and connection paths is effected automatically through an exchange so that by the interconnection the amplifiers of the user stations connected together are switched on and engaged signals are fed to the user stations remaining at the time, characterized in that in the said exchange a microcomputer is provided which through input-output units which receive and emit d.c. voltage signals, is connected to the line and connection circuits in the exchange which are arranged on three types of modular units separate one from another, at least one said modular unit being provided of each of the following types, namely
(a) a linear modular unit upon which a coupling circuit is arranged through which each line is connected in a d.c. mode to one of the input-output units;
(b) a connection modular unit upon which for each predetermined possibility of connection an electronically controllable connection switching contrivance is arranged the control input to which is connected to one of the input-output units; and
(c) a call station modular unit upon which for each user station a transformer is arranged the primary winding of which is connected in each instance to a user station whilst a central tapping on the primary winding can be connected through one of the input-output units to a source of voltage and the secondary winding of which is connectable by means of a predetermined selection of the said electronically controllable connection switching contrivance in each instance to the secondary winding of the other selected transformers; and that the interconnection of the line paths and connection paths is effected under programmed control signals from the microcomputer.
2. Switching equipment as claimed in
Claim 1, wherein on each said modular unit the circuits are arranged, which are associated in each instance with a plurality of lines or connections or call stations.
3. Switching equipment as claimed in
Claim 1 or Claim 2, wherein each of the said modular units is associated with a predetermined maximum number of line or connection circuits.
4. Switching equipment as claimed in any of Claims 1 to 3, wherein one end of each of the secondary windings of the said transformers is connected to earth and the other end is connected to the said electrically controllable connection switching contrivance associated therewith.
5. Switching equipment as claimed in any of Claims 1 to 4, wherein the said coupling circuits contain devices for conversion of voltage from the operating voltage of the simplex or duplex intercom system or public address system to the operating voltage of the inputoutput units.
6. Switching equipment as claimed in
Claim 5, wherein the coupling circuits are constituted by d.c. termination sets.
7. Switching equipment as claimed in any of Claims 1 to 6, wherein the central tappings on the primary windings of the said transformers of the call station modular units are connected through a device for the conversion of d.c. voltage from the operating voltage of the input-output units to the operating voltage of the simplex or duplex intercom system or public address system in each instance directly to a d.c. voltage output from one of the said input-output units.
8. Switching equipment as claimed in any of Claims 1 to 7, wherein the connection switching contrivances are arranged on the connection modular units in at least one interconnection matrix, where one interconnection point is associated with each connection switching contrivance and in each instance a predetermined number of interconnection points is used under programmed control for the interconnection of the connection paths.
9. Switching equipment as claimed in
Claim 8, wherein the connection switching contrivances are arranged on the connection modular units in separate groups in which the connection switching contrivances of each group are arranged in one interconnection matrix.
10. Switching equipment as claimed in
Claim 9, wherein predetermined groups of the connection switching contrivances are interconnected together in cascade.
11. Switching equipment as claimed in
Claim 1, substantially as hereinbefore described with particular reference to the accompanying drawings.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE19782837950 DE2837950C2 (en) | 1978-08-31 | 1978-08-31 | Switching device for a button-controlled exchange, counter or loudspeaker system |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB2029165A true GB2029165A (en) | 1980-03-12 |
| GB2029165B GB2029165B (en) | 1982-08-25 |
Family
ID=6048319
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB7928665A Expired GB2029165B (en) | 1978-08-31 | 1979-08-16 | Switching equipment for a keycontrolled intercom or public address system |
Country Status (6)
| Country | Link |
|---|---|
| AT (1) | AT372560B (en) |
| BE (1) | BE878527A (en) |
| CH (1) | CH645493A5 (en) |
| DE (1) | DE2837950C2 (en) |
| GB (1) | GB2029165B (en) |
| NL (1) | NL183264C (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3000858C2 (en) * | 1980-01-11 | 1986-11-13 | Neumann Elektronik GmbH, 4330 Mülheim | Button-controlled exchange, counter or loudspeaker system |
| DE3214657C2 (en) * | 1982-04-21 | 1985-07-04 | ANT Nachrichtentechnik GmbH, 7150 Backnang | Device for voice and / or data switching and transmission |
| DE4107593C1 (en) * | 1991-03-09 | 1992-05-21 | Fraunhofer-Gesellschaft Zur Foerderung Der Angewandten Forschung Ev, 8000 Muenchen, De | |
| DE4107591C1 (en) * | 1991-03-09 | 1992-03-05 | Fraunhofer-Gesellschaft Zur Foerderung Der Angewandten Forschung Ev, 8000 Muenchen, De | |
| DE4236046C1 (en) * | 1992-10-24 | 1993-11-25 | Loh Kg Ritto Werk | Intercom system with centralised control - uses duplex amplifiers in connection path between calling and called speech stations with respective amplifier paths for each direction |
| DE4334906C2 (en) * | 1993-10-13 | 1997-05-07 | Neumann Elektronik Gmbh | Device for the transmission of call and occupancy status signals from two-way or intercom systems with line selection via a two-wire transmission line |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE1437967B2 (en) * | 1965-04-28 | 1970-05-21 | Telefunken Patentverwertungsgesellschaft Mbh, 7900 Ulm | Circuit arrangement for a button-controlled intercom system |
| DE2434321C3 (en) * | 1974-07-17 | 1983-12-08 | Neumann Elektronik GmbH, 4330 Mülheim | Circuit arrangement for button-controlled intercom, intercom or loudspeaker systems |
| DE2741000C2 (en) * | 1977-09-12 | 1982-04-15 | Industronic, Industrie-Electronic Gmbh & Co Kg, 6980 Wertheim | Line-bound transmission system for speech communication and information processing |
-
1978
- 1978-08-31 DE DE19782837950 patent/DE2837950C2/en not_active Expired
-
1979
- 1979-07-04 NL NL7905213A patent/NL183264C/en not_active IP Right Cessation
- 1979-07-04 AT AT464879A patent/AT372560B/en not_active IP Right Cessation
- 1979-08-16 GB GB7928665A patent/GB2029165B/en not_active Expired
- 1979-08-21 CH CH762779A patent/CH645493A5/en not_active IP Right Cessation
- 1979-08-30 BE BE0/196962A patent/BE878527A/en not_active IP Right Cessation
Also Published As
| Publication number | Publication date |
|---|---|
| DE2837950B1 (en) | 1980-02-28 |
| NL7905213A (en) | 1980-03-04 |
| DE2837950C2 (en) | 1986-11-13 |
| NL183264C (en) | 1988-09-01 |
| BE878527A (en) | 1979-12-17 |
| ATA464879A (en) | 1983-02-15 |
| AT372560B (en) | 1983-10-25 |
| NL183264B (en) | 1988-04-05 |
| GB2029165B (en) | 1982-08-25 |
| CH645493A5 (en) | 1984-09-28 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| 746 | Register noted 'licences of right' (sect. 46/1977) | ||
| PCNP | Patent ceased through non-payment of renewal fee |
Effective date: 19960816 |