GB2044503A - Communications system - Google Patents

Abstract

A multi-channel communications system comprises a plurality of remote controlled transmitters, a plurality of remote controlled receivers, and a central control unit provided with a memory, means for introducing data into the memory representative of at least one desired system status, and means for reading out from the memory the data representative of the or any one desired system status. The transmitters and receivers may be automatically controlled such that the system status represented by the read out data is established <IMAGE>

Description

SPECIFICATION Communications system The present invention relates to communications systems, and in particular to multi-channel communications systems such as are required for naval applications.

Multi-channel naval communications systems comprise a plurality of receivers, for example eleven, and a plurality of transmitters, for example six. Conventionally each of the receivers and transmitters has been manually tuned in accordance with a receiver/transmitter status plan which is regularly updated. Manual tuning requires care and even highly competent operators can make mistakes. Furthermore manual tuning takes time. During an emergency the time taken to tune the system to a desired status and mistakes made by operators can be critical.

Remote controlled receivers and transmitters are known which enable a system's status to be established from a remote location. The use of such remote controlled units does not however radically reduce the requirement for highly competent operators nor greatly increase the speed at which a desired system status can be established.

It is an object of the present invention to provide a system which can be controlled rapidly and reliably and which does not require a large number of highly trained operators.

According to the present invention, there is provided a multi-channel communications system comprising a plurality of remote controlled transmitters, a plurality of remote controlled receivers, and a central control unit from which each of the transmitters and receivers can be controlled, characterised in that the central control unit comprises a memory, means for introducing data into the memory representative of at least one desired system status, means for reading out from the memory the data representative of the or any one desired system status, and means for automatically controlling the transmitters and receivers such that the system status represented by the read out data is established.

The invention enables a single operator to establish a desired system status substantially instantaneously on the basis of previously introduced data which can be carefully checked at the time of its introduction. Thus speed and reliability is achieved.

The term "system status" is used throughout this specification to mean the state of tuning of the various components in the system. For example if a predetermined system status is established, each transmitter and receiver will be tuned to a predetermined respective frequency, bandwidth, working state (simplex or duplex) etc.

Preferably the system comprises a visual display unit (VDU) on which data introduced into or read out from the memory may be displayed. Thus the status of the system can be displayed and data introduced into the memory can be checked.

Preferably the VDU displays data representative of actual system status relayed back to the central control unit from the transmitters and receivers rather than data read out directly from the memory. This ensures that the displayed data reflects true system status rather than desired system status.

Emergency control facilities are preferably provided so that if a component of the central control unit such as the VDU breaks down the correctly functioning components can still be remotely controlled. The receivers and transmitters are preferably also locally controllable so that if the central control unit put out of action the entire system is not rendered inoperative.

Means are preferably provided to monitor the frequency required for the transmitters and receivers and to inhibit selections of transmission frequencies which would be dangerously close to selected reception frequencies.

Preferably faulty components such as receivers and transmitters can be isolated and individually remotely controlled by a central diagnostic facility. The diagnostic facility may comprise controls which form part of the emergency control facilities of the central control unit.

Thus by employing known diagnostic techniques the operator can locate faults down to modular level such that repair by replacement of faulty modules is a routine operation.

Mean are preferably provided to switch one receiver to an emergency frequency automatically at half-hourly intervals in accordance with international emergency frequency listening regulations. This avoids the possibility of the operator omitting to make the required routine receiver adjustments.

An embodiment of the present invention will now be described, by way of example, with reference to the accompanying drawing, which is a schematic diagram of the transmission and reception equipment and the central control unit of a system embodying the invention.

Referring to the drawing, a plurality of remote HF receivers in a rack 1, a plurality of remote HF transmitters in racks 2, 3, 4 and 5, and VHF/UHF transceivers in a rack 6 are controlled by signals applied to data highways 7, 8 and 9 from a central control unit 1 0.

The central control unit 10 comprises a memory into which data representative of any desired system tuning status can be introduced by way of a keyboard. A data processor which can be controlled by the keyboard is arranged to select data from the memory for application to the highways 7, 8 and 9. Thus information relating to more than one system status can be stored in the memory and any one system status can be established substantially instantaneously by simple manipulation of the keyboard.

In detail, the central control unit comprises a Hewlett Packard HP 21 13E minicomputer 11, a keyboard 12, and a local VDU 1 3. The keyboard and local VDU are in the form of an HP 2645A console connected to the mini-computer by interface 14. An HP 1 2960A disc drive 1 5 provides a 4.9K bytes storage medium for the system programming and page memories. The entire system is normally controlled from the keyboard 12, the data highways 7, 8 and 9 carrying tuning control data to the HF receiver rack 1, the HF transmitter racks 2, 3, 4 and 5, and the VHF/UHF rack 6, and revertive data back to the central control unit indicative of the tuning of the equipment in the racks 1 to 6.

The HF receiver rack 1 comprises ten Redifon R1007 receivers 16, each of which comprises a Redifon R 1000 series receiver mainframe with a remote control interface replacing the front panel, and one Redifon R1006 unit 17, which comprises a Redifon R1000 series receiver mainframe with a remote control interface and a Redifon RC1000 remote control unit front panel. All eleven receiver units are connected to the data highway 7. The remote control interfaces are "intelligent", containing a microprocessor to translate command data into control signals and to provide revertive data confirming commands by indicating the receiver tuning status.

Each R1007 provides up to 96 channel data stores to hold the parameters of signals of interest. These are maintained by battery in the event of power failure for several days. The current status is also stored so that following a power failure the receiver's last set condition is reinstated.

The receiver may be instructed to scan through a tabulated list of channels set up from the control source or sweep through a frequency band continuously with pre-selected parameters.

The R 1006 receiver may be controlled from its own controls or from a separate remote control unit which may be either another R 1006 or the mini-computer 1 1 of the central control unit. The receiver controls may also be used to control up to 99 other R1006 or R1007 receivers remotely. The R1006 is specifically designed for systems where local and remote control of receivers is required, or where the control unit for the receiver system is also required to be usable as a search receiver. The receivers 1 6 and 1 7 are connected to conventional eight metre type AWY whip antenna. The received rf signal is passed from the antenna via low pass filters with a cut off of 31 MHz to a passive splitter unit. As the antenna, low pass filters and passive splitter units are purely conventional they are not described in detail or shown herein.A system interface unit 1 8 provides the interface between the equipment of rack 1 and the rest of the system. Interface unit 1 8 takes audio and mute/desense lines from the receivers, and converts them into suitable levels for transmission to a desense and mute exchange described below. Unit 1 8 also comprises switches (not shown) which when opened enable the rack 1 to be operated completely isolated from the central control unit 1 0.

The VH F/ U H F rack 6 comprises nine U H F tranceivers TRT type ER M 8000 identified by numerals 1 9. Each tranceiver 1 9 comprises serial/parallel interface units. Six of the tranceivers 1 9 are connected to an Airtech model 246-2 combined antenna (not shown) by twelve Airtech multicouplers, six in respect of reception, six in respect of transmission. The other three UHF tranceivers 1 9 operate independently, each being provided with a UHF Discone Antenna type OD310.

Each transceiver 1 9 has a programmable controller which provides frequency and channel selection in conjunction with a twenty channel memory. The multicouplers are controlled in step with the transceivers by frequency data provided by the programmable controller.

The VHF/UHF rack 6 comprises two VHF transceivers Plessey type PTR 1741 identified by numeral 20. Each transceiver 10 is connected to its own discrete VHF quarter wave ground plane antenna (not shown).

The VHF/UHF rack 6 is connected to data highway 9 by an interface unit 21. The interface 21 enables the isolation of the VHF/UHF rack 6 from the central control unit 10 so that the VHF/UHF transceivers can be controlled locally independently of the rest of the system.

A highway select switch panel 22 is provided in the central control unit 10 which controls highway switch 23 between receiver 1 7 and receivers 16, switches 24 and 25 connected to an R1006 emergency control receiver 26 and an R1006 search receiver 27 respectively, switch 28 connected to a Redifon SD1006 emergency transmitter drive unit 29 with an associated tuning interface 30, switch 31 connected to an emergency Redifon 1006 VHF/UHF control unit 32, and switches 33, 34 and 35 connected to data highways 7, 8 and 9 respectively. Normally switch 23 allows control data to pass to but not from the receiver 17, switches 33, 34 and 35 are closed (passing data), and switches 24, 25, 27 and 31 are open. The central control unit 10 also comprises a tactical state command unit 36, a time insertion unit 37, and an emergency tune command unit 38.

The racks 4 and 5 comprise identical 1 Kilowatt transmitters each including the following Redifon equipment: SD2 transmitter drive unit RFS14 Post Selector 6746 AC power supply unit GA485 IKW linear amplifier RC1 26B Unit control panel AFU 1 Antenna filter ACU17C antenna tuning control unit System interface unit To simplify the drawing, the drawing only shows the transmitter drive unit 39, the antenna tuning control unit 40, and the interface unit 41.

The Redifon SD2 frequency synthesised transmitter drive unit 39 provides 290,000 channels in 10 Hz steps from 1 to 29.0000 MHz, it has eleven selectable modes of transmission and develops a completely modulated RF signal output at 100 milliwatt.

The drive unit 39 may be used in conjunction with an external frequency standard if necessary. When an external frequency standard is supplied, the internal standard phase locks on the external signal.

The drive unit 39 has 99 channels which can be pre-set and 'called up' by remote control, but may be locally operated. On local operation, frequency is rapidly and positively set by six decade switches which display the nominal carrier frequency, no tuning is necessary. A single switch selects the service modes which cover Cw(A1,A2J), MCW(A2,A2H),DSB(A3), compatible AM(A3H),SSB with pilot carrier at -16dB or -20dB levels, (A3A) or with fully suppressed carrier (A3J) and ISB(A3B).

Input signals may be in the form of d.c. keying or of audio frequency (tone or speech) from an Electret or dynamic microphone or from either of two 600 ohm balanced lines. The post selector is used to suppress all harmonic and spurious signals in the output from the drive unit 39.

Tuned circuits within the post selector are tuned to the transmission frequency by BCD control signals from the drive unit 39. Final tuning however is carried out on a sampled RF output signal. The output from this unit drives the linear power amplifier.

The power supply unit provides all the power necessary to drive the linear amplifier from the main supply.

The linear amplifier is a broadband linear amplifier which operates over the 1.5 to 30 MHz range with a power output of 1 kilowatt CW or p.e.p. The amplifier requires no tuning or loading adjustment over the whole frequency range.

The unit control panel contains sockets for headset and CW key for local working.

The antenna filter is a harmonic rejecting antenna filter.

The antenna tuning control unit 40 is used to control a conventional ACU 1 7 automatic tuning unit which is mounted near the transmit antenna in the form of an AWW 10 metre whip.

The function of the control unit 40 is to provide the power and control signals required by the automatic tuning unit.

The system interface unit 41 provides the interface between the rack equipment and the rest of the system. It takes the audio and mute/desense lines from the drive unit 39 and converts them into suitable levels for the desense and mute exchange described below. The interface unit also provides the switching to enable the rack to be operated on the audio side, from the headset socket on the unit control panel. The racks 2 and 3 comprise identical pairs of 100 watt transmitters, each transmitter including the following Redifon equipment: SD2 transmitter drive unit RFS1 4 post selector PU220N power unit HFA125 linear power amplifier RC 126 B control panel ACU20 antenna tuning control unit System interface unit To simplify the drawing, only the transmitter drive unit 39 and the aerial tuning control units 40 are shown.The system interface unit is a component of interface unit 41. The other components are described above or are equivalent in operation to components of the 1 Kw transmitter described above. The 1 00W transmitters are fully automatic in operation; but they can also be operated in the local mode if required. Each transmitter is connected to its own discrete 8 metre AWY whip antenna.

The interface 41 enables the isolation of the racks 2, 3, 4 and 5 from the central control unit 10 so that the HF transmitters can be controlled locally completely independently of the rest of the system.

The transfer of data along the various data highways is achieved using conventional multiplex techniques. The data highways carry both tuning command data to the system components and revertive data indicative of the actual tuning stage of the components back to the central control unit.

The components of the central control unit will now be described in detail.

The mini-computer 11 processes information, and the interface 14 then interpretes the information into a form which addressed items of equipment in the system will recognize. This interpretation normally consists simply of level changing. The computer 11 performs two main duties: assembly and distribution. Assembly involves the computer in taking information from a number of sources in the system and assembling the data to be re-distributed in appropriate form. Distribution involves the computer in receiving data from a number of sources, "reading" the data and deciding which items of equipment should receive the information. It then routes the data accordingly.

To control the computer, the operator puts in the relevant information using the keyboard 1 2.

The computer 11 then takes this information and converts it to machine codes. The information is then assembled into the right order and routed to the disc memory 1 5. The computer 11 also takes the information and decides which items of equipment require updating in view of the received information. It then routes the information to the appropriate item via the interface 14.

The computer 11 also allows the operator to address the memory 1 5 directly, without changing the state of the system, as will be described in greater depth later. The operator goes into a 'closed loop' made by calling up the desired page from the memory, and then inserting information as before, using the keyboard 1 2. The computer then commands the disc memory 1 5 to go to the relevant part of the loop, the computer 11 takes the data from the disc and inserts the data into its correct location on the VDU 1 3.

The VDU 1 3 obtains its in formation from two sources. The non-changeable data, i.e. receiver number, the word 'frequency' etc., comes from the disc drive 1 5. The operator changeable data, i.e. channel number, frequency allocation etc., is obtained from the revertive data on data highways 7, 8, 9. The computer 11 thus has to switch the source of data going to the VDU, as the page is scanned.

The operational organisation of the system is described in further detail below.

The receiver 27 is used in two main modes: (i) To provide a control back up system in the event of the computer 11 failing; (ii) As a channelised receiver the emergency use and as part of the emergency facility.

Should the computer not be available then the receiver can be brought 'on line' by activating its data highway switch 25, using the highway selector unit 22. Once "on line", it can be be used as a control unit to control any other receiver connected to data highway 7. The SD 1006 emergency transmitter drive unit 29 can be used as an emergency transmitter, or as a control unit, controlling any of the MF/HF transmitter drive units 39 connected to data highway 8. The transmitter 29 must be switched onto the data highway 8 by activating data highway switch 28 using the highway selector unit 22. The receiver 26 has three main modes of operation: (i) The unit can be used by the operator as a 'local' receiver for 'search' purposes. It is then completely isolated by highway switch 24 from the main control system and is used exclusively by the operator.

(ii) The unit can be operated by the computer, with switch 24 closed. Control and operating procedure is as for any of the other receivers 16, 1 7.

(iii) In the event of an emergency the unit, after being selected by the highway selector 22 closing switch 24 can be used as a controller in the system, like the emergency receiver 27.

VHF/UHF remote control unit 32 may be connected to data highway 9 by closure of switch 31 by selector 22. It can then control the VHF or the UHF transceivers on rack 6 in the event of a computer failure, or the computer being unavailable (i.e. during routine maintenance). The highway selector unit 22 consists of a front panel supporting switches which may be used to bring any desired control units 'on line' -in the control mode by appropriate actuation of the highway switches 23, 24, 25, 28, 31, 33, 34 and 35. The switches themselves are in the form of relays.

The emergency tune command unit 38 is used in emergency only. If the computer 11 fails for example, the switches on the unit's front panel can be used to send 'tune initiate' pulses to the transmitters.

The tactical selelction unit consists of a panel with six push-button keys. These select respective action states as described below.

The emergency facility of the system comprises essentially the following Redifon equipment: (i) SD1006 drive unit, local/remote, 29 (ii) R1006 receiver, local/remote, 26 (iii) Tuning interface, type 11824, 30 (iv) HFA125, HF power amplifier (v) ACU 1 5 antenna tuning unit (vi) MFA125, MF power amplifier (vii) ACU16 antenna tuning unit (viii) Power supply type PU220N The amplifiers, power supply, and antenna tuning units are conventional and are not shown in the drawing.

The drive unit 29 is the drive unit for the MF/HF Emergency facility, and also doubles as the emergency control unit for the system. When used as the emergency facility drive unit, the unit 29 is completely autonomous, in both control and signal path modes. The rest of the system can fail completely, and this will not affect the operation of the emergency facility.

As in the case of drive unit 39 described above, unit 29 is associated with a post selector and an antenna tuning unit (not shown).

The receiver 26 is the receiver used in the MF/HF Emergency facility. As for the drive unit 29, the receiver 26 is also used as a system back up control, and is completely autonomous from the main system when used in the emergency facility role. The tuning interface 30, on receiving a 'tune initiate' command from the computer, goes through a tune up procedure. The first step in the procedure is to detect if an a.f. signal is present. If there is no signal present, then the interface unit will insert one. This is because to tune up the antenna tuning unit a signal must be present, and as the tune up is usually carried out on AM (A3) an audio signal must be present to activate the power amplifier. Thereafter, the interface unit sends an activate pulse to the post selector. This causes the post selector to 'tune up'.In the final part of the cycle, the interface unit causes the antenna tuning unit itself to tune up to the required working state.

In an emergency, the 'tune initiate' command may be provided from the emergency tune command unit 38.

If a frequency in the range 1.5 to 30 MHz is selected on the emergency drive unit 29, the HFA125 power amplifier will be automatically selected. The RF signal from the drive unit 29 is then routed to the HFA125 and then to the ACU 1 5 antenna tuning unit.

If a frequency in the range 330 to 550 KHz is selected on the emergency drive unit 29, the MFA125 power amplifier will be automatically selelcted. The RF signal from the drive unit 29 is then routed to the MFA125 and then to the ACU 1 6 antenna tuning unit.

Having described the system layout in general terms, the following is a description of the operational organisation of the system of the drawing.

The desense and mute exchange (DME) 42 receives data from the VDU 1 2 via interface 14 down a three wire cable in line 43. The three wires are allocated as follows: (1) Clock (2) Data (3) System Ov When the data reaches the DME 42 it is decoded. The decoded data then selects which receiver has its mute and desense lines matched up with which transmitter drive unit. The data is decoded at the exchange end of the data highway to avoid excessively large numbers of cables running between the units.

Also in the data coming from the VDU, is the simplex/duplex command. This informs the exchange 42 whether the receiver/drive unit pair is working in the simplex or duplex mode. If it is in the duplex mode the unit adjusts the relevant circuitry.

Incorporated into the DME is an illegal frequency detector (I.F.D.) 44. The IFD has two main data inputs. One input 45 receives frequency data from the receivers, the other input 46 receives frequency data from the HF transmitter drive units 39. Hence the IFD 44 knows what frequencies all the drive units 39 are set to and what frequencies all the receivers 16, 1 7 are set to. The unit is then informed by the DME 42 which receivers are paired to which transmitters.

The lFD'is then able to match up the frequencies of each half of the pair. In the IFD is a micro processor. Into the microprocessor is fed the frequencies of each of the six drive units 39. The processor then calculates + 10% of the frequency and places the answer in a buffer store. The processor then examines the frequencies of the six matching receivers. If the frequency of a receiver is within + 10% of the frequency of its matched drive unit, then it sends out an illegal frequency command pulse to that pair. This pulse inhibits the drive unit output and therefore prevents the transmitter from keying until the receiver has been retuned further away from the transmitter frequency. If however, the pair which has been detected as being illegal is in simplex, the inhibit line itself is inhibited.This is to enable single frequency simplex working.

The illegal frequency command pulse is also routed back to the VDU for appropriate display.

Thus, the unit takes the frequency information from a matched receiver and drive unit and compares them. If they are within 10% of each other and the unit has been informed that the pair are working duplex, then an illegal frequency command is issued and the transmitter is disabled from working.

Remote VDU's 47 enable the system status to be monitored at remote locations, but does not enable any changes to be made to the system status.

Data storage in the memory 1 5 of the computer 11 is based on the page and travelling cursor system. There are fifty one pages, allocation details of which are as follows: 00 (HOME) INDEX PART 1 01 INDEX PART 2 02 HF SYSTEM STATUS 03 UHF SYSTEMS STATUS 04 TX1 CHANNEL ALLOCATION 05 TX2 CHANNEL ALLOCATION 06 TX3 CHANNEL ALLOCATION 07 TX4 CHANNEL ALLOCATION 08 TX5 CHANNEL ALLOCATION 09 TX6 CHANNEL ALLOCATION 10 RX1 CHANNEL ALLOCATION 11 RX2 CHANNEL ALLOCATION 12 RX3 CHANNEL ALLOCATION 13 RX4 CHANNEL ALLOCATION 14 RX5 CHANNEL ALLOCATION 15 RX6 CHANNEL ALLOCATION 16 RX7 CHANNEL ALLOCATION 17 RX8 CHANNEL ALLOCATION 18 RX9 CHANNEL ALLOCATION 19 RX10 CHANNEL ALLOCATION 20 RX11 CHANNEL ALLOCATION 21 RX12 CHANNEL ALLOCATION 22 RX 13 CHANNEL ALLOCATION 23 RX14 CHANNEL ALLOCATION 24 UHF1 CHANNEL ALLOCATION 25 UHF2 CHANNEL ALLOCATION 26 UHF3 CHANNEL ALLOCATION 27 UHF4 CHANNEL ALLOCATION 28 UH F5 CHANNEL ALLOCATION 29 UHF6 CHANNEL ALLOCATION 30 UHF7 CHANNEL ALLOCATION 31 UHF8 CHANNEL ALLOCATION 32 UHF9 CHANNEL ALLOCATION 33 VHF1 CHANNEL ALLOCATION 34 VHF2 CHANNEL ALLOCATION 35 SPARE 36 RX CHANNEL SCAN ALLOCATION 37 TSU PROGRAMME 1 PART 1 38 TSU PROGRAMME 1 PART 2 39 TSU PROGRAMME 2 PART 1 40 TSU PROGRAMME 2 PART 2 41 TSU PROGRAMME 3 PART 1 42 TSU PROGRAMME 3 PART 2 43 TSU PROGRAMME 4 PART 1 44 TSU PROGRAMME 4 PART 2 45 TSU PROGRAMME 5 PART 1 46 TSU PROGRAMME 5 PART 2 47 TSU PROGRAMME 6 PART 1 48 TSU PROGRAMME 6 PART 2 49 EMERGENCY TX CHANNEL ALLOCATION 50 EMERGENCY RX CHANNEL ALLOCATION Page 00 is called up by pressing a "home" button on the keyboard 1 2. The resulting picture on the VDU screen, which picture is the first page of the basic index, has 25 lines and covers pages 01 to 25. Pages 26 to 50 inclusive are covered on the second page of the index (page 01). From the index the operator decides which page he is interested in. To obtain the desired page, the operator types the page number on keyboard 12, and presses a 'return' key. The desired page will then appear on the VDU screen 1 3.

As an example, page 02 displays the actual state of the HF communications at the time the page is selected. This page is one of only two pages that can communicate directly with the HF control highway.

The page displays the revertive data supplied by the transmitter drive units and the receivers.

Any information changes made on this page are instantly carried out in the main system.

A typical readout of page 02 is set out below: REDIFON CETAC SYSTEM 14.02 GMT PAGE 02 H.F. SYSTEM STATUS SP, 2, 182 TX 1, CH 19, FR 4267 KHZ, MO A1, CO I, MRX 2, AFI 1, WS SIM, I, READY TX 2, CH 14, FR 6469 KHZ, MO A2H,CO I, MRX 14,AFI 1, WS SIM. I, READY TX 3, CH 0,4 FR12790 KHZ, MO F1 ,CO I, MRX 8, AFI 1, WS DUP, I, READY TX 4, CH 0.9, FR17072 KHZ, MO A3H,CO O, MRX 10,AFI 2, WS DUP, I, READY TX 5, CH 11, FR12006 KHZ, MO A3J,CO O, MRX 1.AFI 1, WS SIM, I, READY TX 6, CH 0,8 FR25887 KHZ, MO A3, CO I, MRX 11,AFI 2, WS SIM, I, READY RX 1, CH 03, FR12006 KHZ, MO A3J,BW 8 KHZ, AGC LG, BF V10, RG V10, MT 5 RX 2, CH 08, FR 4267 KHZ, MO A1, BW .3 KHZ, AGC DF, BF V 5, RG V 7, MT 1 RX 3, CH 12, FR 6578 KHZ, MO A2, BW 6 KHZ, AGC SH, BF V 4, RG V10, MT RX 4, CH 23, FR11345 KHZ, MO A3, BW 1 KHZ, AGC LG, BF F, RG V10, MT RX 5, CH 13, FR 1412 KHZ, MO F1, BW .3 KHZ, AGC LG, BF F, RG V10, MT 3 RX 6, CH 24, FR 500 KHZ, MO AWJ,BW 8 KHZ, AGC SHY, BF F, RG V 5, MT RX 7, CH 09, FR22349 KHZ, MO AEH,BW 6 KHZ, AGC SH, BF F, RG V10, MT 4 RX 8, CH 18, FR14287 KHZ, MO A3H,BW .3 KHZ, AGC SH, BF F, RG V 6, MT RX 9, CH 12, FR 3561 KHZ, MO A3J,BW 1 KHZ, AGC DF, BF V 7, RG V10, MT RX 10, CH 25, FR 4256 KHZ, MO A3B,BW 6 KHZ, AGC LG, BF V 3, RG V 2, MT RXEM, CH 09, FR 2182 KHZ, MO A3, BW 8 KHZ, AGC SH, BF F 1, RG V10, MTEM TXEM, CH 09, FR 2182 KHZ, MO A3, CO I, MRX EM, AFI 2 WS SIM, I READY Referring to the above readout of page 02, those portions of each line which can be changed by the operator have been underlined on the first line only (Note: the underlining does not appear on the actual display). The abbreviation used are explained as follows: RX1 :-This indicates that line seven is allocated to receiver one.

CH:-This indicates the channel number to which the receiver (or a transmitter drive unit) is working to, at the displayed time.

FR:-Frequency. In this space, any frequency within the receiver or transmitter range can be inserted. The frequency to be used is typed in KHZ.

MO:--Mode. Any mode listed below can be typed in: For a receiver:-A1, A2, A3, A3A, A2J, A2H, A3H, A3J, A3B, For a transmitter:-A1, A2, A3, A3A(-16), A3A(-20), A2J, A2H, A3H, A3B(-16), A3B(-20).

SB:-Sideband. Where applicable, LSB or USB can be typed in.

BW:-Bandwidth. Where applicable, 0.3 KHZ, 1 KHZ, 3 KHZ, 6KHZ or 8 KHZ can be typed in.

AGC:-Automatic gain control. In this space LG (long) OF (Off) or SH (short) can be typed in.

BFO:--The BFO used in the receiver can be of two different types. Fixed and variable. To simulate a typical potentiometer control, the sweep is given a 1-10 designation.

So, F (Fixed) or V1-10 (V, variable) can be typed in.

RFG:-R F gain. As for the BFO control, a variable designation is given, hence V1 -V1 0 can be typed in.

MTX:-Mating transmitter drive unit. Using this position a receiver can be matched up to any transmitter drive unit to produce a transmit/receive system. This information is passed from the VDU to the desense and mute exchange 42 which matches up the relevant lines.

TX1 :-This means that line one is allocated to transmitter drive unit number one.

CO:--Compliance, In or Out can be selected.

MRX:-This shows the receiver if any, to which the transmitter has been designated. This space cannot be typed in as the information is obtained from the desense and mute exchange.

AFI:--AF input. There is a choice of audio inputs on the HF transmitter drive units 39. If 1 is typed in the unit selects one input, and if 2 is typed in, the unit selects the other input.

WS:-Working state. D (Duplex) or S (Simplex) can be typed in this space. This selects the appropriate state in the simplex/duplex switch, (located in the desense and mute exchange) for the relevant transmit/receive pair.

1:-Initiate. The appropriate transmitter drive units 39 have to be retuned whenever a change of frequency has been carried out. Typing an I at the end of the line will cause a pulse to be sent to the drive unit tuning interfaces 40, which will then retune to the new frequency.

Page 03 displays the working state of the UHF transceivers 19 in a manner similar to the display of the HF system status on page 02. Page 03 communicates directly with the UHF data highway 9.

Subsequent pages form a 'closed loop' part of the system as they can be edited by typing in commands but the VDU is addressing only the computer memory. The pages do not have direct access to the system. These subsequent pages show what frequencies, types of mode etc. have been allocated to each channel. Changing data on these pages only alters the memory, and the changes are not implemented until the channel concerned has been called up via page 02 or 03. Each page shows the channel allocation for each unit. There is one page per unit. Therefore page 04 shows all the channel allocations for TX1.

It should be noted however, the the closed loop part of the system, can be used at any time alongside the main system. In other words, using this facility will not inhibit the functioning of any part of the main system.

The following procedure assumes the all equipments are working correctly, and that all units are ready for use: When the operator first assumes command, his first action is to acquaint himself with the status of the system at the time. He therefore presses the home button on his keyboard. This calls up onto the screen page 00, which gives the general index for the page system. From that he reads off the heading 'HF SYSTEMS' and the page number, 02. The operator then types in 02 followed by the return key. This will then call up page 02. By observing page 02 the operator can instantly see what frequency, mode etc. all the units in the system are set to at that moment of time. If an operator wants to see the status of the complete HF system at anytime, he can call up page 02.

When the operator calls up page 02, he will see a short line at the top of the page at the left hand side. This is the travelling cursor. When first called up, the cursor will be to the left of the word TX1, i.e. line one. Next to the home button the operator has four buttons with directional arrows on them, these point up, down, to the left and to the right. These are the direction control buttons for the cursor. Pushing a button will cause the cursor to travel one cursor space in the direction of the button arrow. A cursor space is the distance to travel to the next changeable piece of information. For instance if the cursor has settled underneath the first digit of the frequency, on a given line of page 02, pressing the travel right cursor button, will cause the cursor to settle underneath the first letter of the mode allocation.As only certain characters of a line can be altered by the operator, the cursor will skip words and only stop underneath the most significant character. The up and down button will cause the cursor to increment in that direction by one line. When a cursor arrives at the start of a line, it automatically addresses that line. This means that the operator can change information safely at any point, knowing that the relevant changes will always be made. It must be remembered however, in order that an equipment can be addressed properly, the operator must always go to the extreme left hand end of a line, before changing any information contained in it.

To change a line of information the operator proceeds as follows: With the cursor set to the start of the relevant line, the operator presses the move right button. This brings the cursor to rest underneath the first digit of the channel identification. The operator then types in the discrete channel number. Then the operator presses the move right button again. This time the cursor settles underneath the first digit of the frequency allocation.

As before he types in the desired numbers. The operator then repeats the operation for the rest of the information carried in the line. If however, the operator does not wish to change a piece of information, under which the cursor has come to rest, he can skip it by pressing the move right button until the cursor is in the desired place. It should be noted however, that the move left button does not operate in the 'shift one space' system. Wherever the cursor is located, pushing the move left button will cause the cursor to move to the extreme left of the line, i.e.

the start of the line. This facility speeds up the editing time.

Setting up the receiver and the transceiver lines is relatively easy, the operator only needs to place characters or digits in the spaces provided. However transmitter lines need an extra insertion. As has already been described the transmitters have antenna tuning units, which along with their post selectors, need to be tuned. If an operator is changing a transmitter line, he must stop at the end of the line. In this space he must type the letter I (for initiate). Once he has typed in this letter, the control VDU sends a tune pulse to the appropriate transmitter system. This causes the units to tune up. When the units are tuned up, they send a signal back to the VDU. This informs the operator that the system is tuned up satisfactorily and that he can carry on with another line.If however, the tune-up was unsuccessful, then the VDU will write up the word 'FAULT' alongside the letter I. The operator should now retype the letter I (assuming that he has not moved the cursor), this can be re-written over the previous I. This is a check that the unsuccessful tune-up was not due to a spurious fault. If the second time, the 'Fault' indication again writes up then further action is necessary. It should be noted however, that in practice, only if the frequency has been changed, will an initiate command be necessary.

This fault indication is also used for other functions. When an operator has typed in the Working State (WS) of a transmitter (this is either simplex or duplex), if he typed in duplex, the 'fault' indication may write up. This means that the IFD has come in and inhibited the transmitter. The frequency display (VDU) of the offending receiver will also flash on and off. He has then to re-allocate the frequencies. The operator can now return to the index (HOME) and decide what other functions he wishes. If say he wants to set up the channels on receiver number 6, he types 1 5 and return. This calls up page 15, which gives the channel allocation for RX6. The method of updating the information is exactly the same as for page 02 previously described.

Page 37 is the first page of the part of the memory concerned with the tactical state unit 36 which is in the form of a panel of six illuminated when pressed switches. Depression of any one switch calls up from the computer 11 a respective tactical state programme. Each tactical state programme contains all the information to set up the complete HF and UHF external communication system. When a programme has been written it can be called forward in its entirity by pressing the appropriate switch on the front panel of the TSU36. This panel is situated in front of the VDU 1 3.

The actuation of a TSU select switch overrides all other programmes and thus gains immediate access to the communications data highway. It is not necessary to have the appropriate TSU programme page selected on the VDU in order to select that status, only the switch has to be pressed. The TSU programme instantly changes the system status to comply with its data.

If page 02 has been selected on the VDU 13, and a TSU button has been pressed, the operator will observe an immediate update on the page as page 02 shows the actual state of the system.

The operator will easily be able to observe that the transfer of information has taken place.

This is because the appropriate TSU switch will be illuminated, and all channel numbers for units on the VDU 1 3 will read 00.

Each TSU programme requires two pages because of the number of transmitters, receivers and transceivers to update.

To call up the first page of the first TSU programme, the operator types 37 and 'RETURN'.

The VDU will then display the first page of the programme. Apart from the heading and one other feature, the page will be identical to the HF data page, 02. The other feature is the channel coding. As has already been described an operator can change channel numbers on page 02. However on the TSU programme, the channel number for all units is 00, so the channel space on the page will show this. Also the operator will not be able to change the channel numbers from 00. Otherwise, the editing and changing or setting up of information on the TSU pages, is identical to pages 02 and 03.

There can be on the TSU pages an information inhibit command. This will be in the form of a key switch on the TSU panel. If the key had been used, the VDU will display the page information as indicated above. However, if the key has not been inserted and an operator 'calls up' a TSU page, then the display will only indicate the following statement:- THIS PAGE CONTAINS RESTRICTED INFORMATION.

ACCESS IS BY KEYHOLDER ONLY.

Page 49 contains the channel allocations for the emergency transmitter control drive unit 29.

This unit used used on the emergency frequency band, As is the case with all the drive units, this unit has up to 99 channels although not all are used. The first seven channels are for emergency frequency allocation and once set in can only be changed or erased by an authorised key holder. This key switch is incorporated on the front panel of the unit. The key switch not only inhibits the seven channels being altered via the units own front panel, but it also prevents them being altered on page 49 of the display.

When the key has been used, the page has the same format and control facilities as pages 04 to 33, that is frequencies, mode etc. are displayed for each channel and can be altered via the travelling cursor. However if the key has not been used, then typing any command onto lines 1-7 will have no effect on the display or the system.

Page 50 is identical to page 49, except that the information refers to the R1 006 emergency receiver 26. As for page 49 the key switch inhibits lines 1-7. The other line can, as before be used normally, This page is the last page of the system.

If it is desired to utilise the emergency facilities, due to for example a breakdown in the keyboard 12, the computer 11 is isolated from the system by opening highway switches 33, 34, 35. Switches 24, 28 and 31 are then closed and the system can be operated in a conventional manner by individually addressing each of the system components when a status change is required. Thus the system is not paralysed by a breakdown in the central data processing equipment.

If the entire central control unit is destroyed, for example by enemy action, the switch 23 can be actuated locally and control of the receivers 16 exerted via receiver 17. Similarly the UHF units and the HF transmitters can be locally controlled.

The TIU 45 has three separate displays on the front panel. These displays are: 1. The GMT time 2. The local time 3. The date.

With reference to this patent application, only the part concerned with the control system will be examined.

There are a set of parallel data lines running between the TIU and the VDU interface. These lines carry the time is GMT, this is in BCD, and also a set of control lines. These control lines bring down the silent period commands.

The VDU interface takes these control lines and displays the time in GMT in the top right hand corner of the display. Whatever page is called up on the VDU, the time will always be displayed in the top right hand corner.

On the hour and on the half hour, the TIU sends a silent period command to the VDU, this lasts exactly 3 minutes. On receipt of this command, the VDU will display alongside the time the legend: (SILENT PERIOD 2.182 KHZ) When this has been displayed the R1006 receiver 26 in the emergency facility will automatically align to 2.1 82 MHZ, in the A3 mode. At the end of the three minute period, the receiver will automatically revert back to the frequency and mode which was being used before the silent period began.

In similar position, on the quarter and three-quarter hours the legend below will be displayed: SILENT PERIOD 500 KHZ As before the receiver 26 will align to the right frequency and mode, in this case 500 KHZ, A2 mode. At the finish of the three minute period, normal working will resume.

The silent period facility will be inhibited if a TSU programme is in progress.

The system can be switched to a diagnostic mode to enable a fault within any driver unit 39 or receiver 16, 1 7 to be resolved. The procedure is as follows: The operator first isolates the faulty receiver or drive unit. Assume for example that receiver number 4 is faulty. The operator then activates the emergency facility which is also the diagnostic centre. Using the emergency receiver 26 he takes over control of receiver number 4 from the V.D.U. 13. He then types in, using the front panel keyboard of the receiver 26, a diagnostic code. The receiver front panel L.E.D. displays will then all change to O's. They will then start to count up. Each number displayed illustrates the test being carried out automatically. When the display ceases to increment, the unit has reached the test at which the receiver fails. The operator can then look up the number in a diagnostic manual. This will tell him which module is faulty. On some tests, faults can be localised down to l.C. level.

If a drive unit 39 is faulty the operator carries out the same procedure but using the emergency facility transmitter 29.

Therefore, an operator can fault find a unit in the system, to or below modular level, totally automatically using the minimum of equipment.

The radio equipment described with reference to the drawings is of course provided with further switching circuits to link the various pieces of equipment with desired user positions. For this purpose a switching matrix is used to interface the equipment to the user positions in conventional manner.

Claims (7)

1. A multi-channel communications system comprising a plurality of remote controlled transmitters, a plurality of remote controlled receivers, and a central control unit from which each of the transmitters and receivers can be controlled, characterised in that the central control unit comprises a memory, means for introducing data into the memory representative of at least one desired system status, means for reading out from the memory the data representative of the or any one desired system status, and means for automatically controlling the transmitters and receivers such that the system status represented by the read out data is established.

2. A multi-channel communications system according to claim 1, comprising a visual display unit on which data introduced into or read out from the memory may be displayed.

3. A multi-channel communications system according to claim 2, wherein the visual display unit displays data representative of actual system status relayed back to the central control unit from the transmitters and receivers, whereby the displayed data reflects true system status.

4. A multi-channel communications system according to any preceding claim, comprising means independent of the automatic control means for remotely controlling the system transmitters and receivers and means for locally controlling the system transmitters and receivers.

5. A multi-channel communications system according to any preceding claim, comprising means for monitoring the frequency required for the transmitters and receivers and for inhibiting selections of transmission frequencies which correspond to selected reception frequencies.

6. A multi-channel communications system according to any preceding claim, comprising means for automatically switching one receiver to an emergency frequency at predetermined intervals.

7. A multi-channel communications system substantially as hereinbefore described with reference to the accompanying drawings.