GB2184325A - Switching system - Google Patents

Abstract

A switching system comprises a switch matrix (3) at least one input (8, 9, 10, 11) and a plurality of outputs (12, 13, 14, 15),or at least one output (12, 13, 14, 15) and a plurality of inputs (8, 9, 10, 11) and selection means (1) adapted to generate an activation signal. The input or inputs and the output or outputs are connected to the switch matrix (3). The switch matrix (3) is switchable to a selected one of a plurality of switch conditions,whereby a selected output can be connected with a selected input, in response to data inputted by an operator. <IMAGE>

Description

SPECIFICATION Switching system This invention relates to a switching system and more particularly relates to an electrical switching system for use in video systems.

It is known to provide a switch matrix which connectsa pturalityof inputsto a pluralityofoutputs.

The switch matrix is switchable between a plurality of different switch conditions and each switch condition connectsthe outputs to selected inputs.

Typically the switch marix comprises a plurality of individual switches which can be switched on or off. In the past it has been usual to establish a particular switch condition by manually switching the switches to either the on orthe off state so that the outputs are connected to the selected inputs.

The establishing of a particular switch condition takes time, and in applications where a large number of switch conditions need to be consecutively established a great deal oftime can be wasted in manually performing the switching.

It is an object ofthe present invention to provide an improved switching system.

This object can be achieved by providing a selection means for effecting automatically a switch matrix condition selected by an operator The operator may input a code to the selection means, and the selection means can translate the code into a signal capable of effecting the switch condition using memory means.

According to the present invention there is provided a switching system comprising a switch matrix, at least one input and a plurality of outputs, orat least one output and a plurality of inputs, said input or inputs and said output or outputs being connected to the switch matrix, and selection means adapted to generate an activation signal, wherein the matrix is switchable to a selected one of a plurality of switch conditions in response to the activation signal, whereby a selected output can be connected with a selected input.

According to another aspect ofthe invention there is provided a video signal switching system comprising a switch matrix, at least one video signal input and a plurality ofvideo signal outputs, or at least one video signal output and a plurality of video signal inputs, said input or inputs and said output or outputs being connected to the switch matrix, and selection means adapted to generate an activation signal, wherein the matrix is switchable to a selected one of a plurality of switch conditions in response to the activation signal, whereby a selected output can be connected with a selected input.

Advantageously the activation signal is generated in response to a selection signal.

Preferably the selection means includes memory means storing information relating a particularselection signal to a particular activation signal.

The activation signal varies according to the selec- tion signal; the switch condition established by the switch matrix depends upon the activation signal, and therefore upon the selection signal.

Preferably the selection means includes input meansto enable an operatorto inputinformation to establish a particular switch condition; the input means may generate the selection signal in response to the data inputted by the operator. The input means may include a keyboard and a VDU,for example.

The operator may input a code through the keyboard, which code determines the selection signal.

Desirably the selction means includes calculating means for calculating the activation signal. The calculating means may be connected to the input means and the memory means. The calculating means may be arranged to calculate the activation signal using the selection signal and the memory means; the calculating means can use the memory means to translate the selection signal into the activation signal.

Advantageously the memory means is programmable so that the activation signal corresponding to a particular selection signal can be varied. The calculating means may be programmedto enablethe memory means to be programmed by the operator.

It is desirable that the memory means is capable of retaining the information stored when its power supply has been switched off. This avoids the need to reprogram the memory means after each shut-down of the system.

The switching system according to the invention can handle D.C. and A.C. electrical current. The system can handle frequencies in the range of, for example, 5 Hzto 100 MHz. In video systems applications particularly good results are obtained in a frequency range of 10 Hzto 15MHz.

In the switching system ofthe present invention a particular selection signal corresponds to a particular switch condition, and by generating a particular selection signal the corresponding switch condition can be established. Since the selection signal can be generated by the operator simply inputting one or more characters, anydesired switch condition can be established very easily and quickly. This greatly reduces the time involved in establishing the switch condition.

Furthermorethecalculating means can be programmed to successively establish a series of switch conditions.

Reference is now made to the accompanying drawings in which: Figure lisa schematic diagram of a switching system acording to the invention; and Figure 2 is a diagrammatic representation of a switch matrix for use with the system of Figure 1.

In Figure 1 a switching system comprises selection means 1 which can generate an activation signal which is transmitted on an electrical line 2. The line 2 is connected between the selection means 1 and a switch matrix 3.

An interface4 is provided in the line 2. Although the interface 4 is shown separate from the selection means 1 andthe switch matrix 3, it will be appreciated thatthe interface 4 could be integral with either the selection means 1 ortheswitch matrix3.

The selection means 1 comprises a microcomputer system which includes input means 5, calculating means 6 and memory means 7.

The input means may comprise, for example, a keyboard (not shown) for inputting data, and a VDU (notshown) for displaying the inputted data. The calculating means 6 and the memory means 7 may comprise a microprocessor having a programmable read only memory.

In the arrangementshown, the switch matrix3 is connected to four inputs 8,9, 10, 11 which may, for example, be video signal inputs. The matrix 3 is also connected to four outputs 12, 13, 14, 15. The switch matrix3 enables any one of the outputs 12,13, 14, 15 to be electrically connected to a selected one ofthe inputs8,9,10,11.

The internal a rrangement of the swich matrix 3 is shown diagrammatically in Figure 2. The matrix 3 consists of 16 switches designated 16 to 31.

The following table shows which inputs and outputs are connected to which switches.

TABLE INPUT/OUTPUT NO. SWITCH NOS. CONNECTED 8 16,17,18,19 9 20,21,22,23 10 24,25,26,27 11 28,29,30,31 12 16,20,24,28 13 17,21,25,29 14 18,22,26,30 15 19,23,27,31 It can be seen that any output can be connected to any selected input. For example, to connect output 13 to input9switch 21 must be "on". In orderto connect the outputs to selected inputs then certain switches will be on and certain switches will be off. If it is desired to connect one outputto only one input then onlyfourswitcheswill beonandtheremainingtwelve switches will be off. The particular arrangement of on and off switches for a particularselection corresponds to a particular switch condition ofthe matrix 3.For example, to connect inputs 8,9,10, 11 1 respectively to outputs 12,13,14,15 requiresthefollowing switch condition: switches 16,21,15 & 1 are on; the remaining switches are off. The switch condition is established bythe activation signal transmitted on line 2.

The operation of the switching system is as follows.

The operatorfirstly decides which outputs and inputs areto be electrically connected. When this has been decided the operator inputs on the input means a character or a series of characters which have been previously assigned to the chosen connection.The operator may have a list relating the characters correspondingto each selection, and the program means 6 can be programmed to provide a display of this list on the VDU.

The inputted character or characters create a selection signal which is fed to the calculating means 6. The calculating means 6 is a program which takes the data fed in by the operator and used the memory means 7 to calculate an activation signal.The memory means 7 contains information which relates the selection signal to the activation signal necessary to establish each switch condition. Thus, the calculating means 6 reads the selection signal, looks up the corresponding activation signal in the memory means 7, and then generates and transmits the activation signal via line 2, to the interface 4 and the switch matrix 3. The interface 4 converts the activation signal from the selection means 1 into a form which can physically operate the switches ofthe matrix 3.The switches may be electronic, electrical, or electromechanical.

The memory means 7 isprogrammablesothatthe characters corresponding two a particular connection can be redefined if necessary. This is a particularly useful feature when large numbers of inputs and outputs are involved. For example with 16 inputs and outputs, there are 16! different switch conditions, and the memory means 7 can onlystore information relating to a relatively small number ofthese. Thus, the programmable nature ofthe memory means enables the configurations which are stored to be varied whenever necessary.

It will be appreciated that the number of inputs and outputs can be chosen according to the requirements of each application. Furthermore, it is possibleforone input to be connected with more than one output, and/or for one output to be connected with more than one input.

The present invention enables a particular switch condition to be established by inputting a unique characterorseries of characters which have been assigned to the particular switch condition. This is simplerand quickerthan earliersystemswhich require the manual switching of each switch in the switch matrix. Moreover, the present invention excludes the possibilities of operator errors such as connecting two inputs with one another.

As explained above, the present invention is parti cularly useful for the transmission of video signals on the inputs and outputs. This application can be used in, for example, TV studios, outside broadcastvehi- clesandtransmission centres.

Claims (11)

1. Aswitching system comprising a switch matrix, at least one input and a plurality of outputs, orat least one output and a plurality of inputs, said input or inputs and said output or outputs being connected to the switch matrix, and selection means adapted to generate an activation signal, wherein the matrix is switchableto a selected one of a pluralityofswitch conditions in responsetothe activation signal,where- by a selected output can be connected with a selected input.

2. Avideo signal switching system comprising a switch matrix, at least one video signal input and a plurality of video signal outputs, or at least one video signal output and a plurality of video signal inputs, said input or inputs and said output or outputs being connected to the switch matrix, and selection means adapted to generate an activation signal, wherein the matrix is switchableto a selected one of a plurality of switch conditions in response to the activation signal, whereby a selected output can be connected with a selected input.

3. A switching system according to Claim 1 or2, wherein the activation signal is generated in response to a selection signal.

4. A switching system according to Claim 3, wherein input means is provided for generating the selection signal in response to data inputted byan operator.

5. A switching system according to Claim 4, wherein the input means is adaptedto receive a code inputted by the operator, and the selection signal depends upon the code.

6. A switching system according to Claim 3,4 or 5, wherein the selection means includes memory means storing information relating a particular selection signal to a particular activation signal.

7. A switching system according to Claim 6, wherein the memory means is programmable so that the activation signal corresponding to a particular selection signal can be varied.

8. A switching system according to any preceding claim, wherein the selection means includes calcula tion means forcalculating the activation signal.

9. A switching system according to Claim 8 when dependent upon Claim 6 or7, wherein the calculating means is adapted to calculate the activation signal using the selection signal and the memory means.

10. A switching system according to Claim 9, wherein the calculating means uses the memory means to translate the selection signal into the activation signal.

11. A switching system substantially as herein described with reference to and as shown in the accompanying drawings.