DA3U6 manual - PA Comms.com
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1. Line Barrier gt o Bargraph and Tx elle 6 F ou Keying Inhibit mm Direct Tx Logic x ss Interface The audio output transformer Txf 3 has a split secondary which has the A C circuit completed with a 2u2 capacitor The keying contacts operate the transmitter by placing a short circuit across the 2u2 capacitor hence when the transmitter is required to send TX ON a low resistance loop appears across the pair The level and endurance whilst playing of the line signal is checked by the alarm circuit connected to the line output User Manual Refreshed Datis type 6 Issue a da3man6a2 pdf Page 20 9 1 Operator Audio Interface Recording The signal from the operator s microphone passes to the microphone pre amplifier in the Operator Audio Interface where level fluctuations are reduced the resulting output has an average level of 20db and is fed via the recording buffer to both announcers input lines simultaneously The store that makes the recording is determined by both the priority and presence of the record command The connector for the operator s headset an eight pin LEMO type is positioned on the front panel of the Operator Audio Interface The messages are prepared locally rather than from a remote headset Monitor Channel The signal fed to the operator s headphones is fr2. Facilities Socket db25 provided to connect PATSI unit Telephone RJ11 cord terminated with 431 jack simulates plain analogue telephone 8 Alarm db9 T7 Key Alarm contacts User Manual Refreshed Datis type 6 Issue a da3man6a2 pdf Page 25 12 Facilities Socket The Navy modification to the original DA6U6 provided the facilities socket on the rear of the Datis intended for connection to a PATSI Datis interface unit that allows EDDS to remotely prepare ATIS broadcasts EDDS takes full control of DATIS when the lock switch on the front panel of DATIS is in the LOCKED position The PATSI interface operates the press button controls and observes the indicator leds Plug in board J provides the facilities socket with the indicator outputs suitable for a conn 2 type remote control it is no longer necessary to have the factory fitted indicator booster board in the rear of Datis that was fitted on mounting pillars behind the upper portion of the DA6U6 backplane With nothing connected to the facilities socket the DA3U6 will operate normally The facilities socket inputs are enabled when the lock switch has been moved to the position that disables the DA3U6 front panel controls Technical Glossary Announcer Digital recorder and reproducer also known as Voice Store Barrier protection barrier for telecommunication circuits Codec Integrated
3. Press Record the led will illuminate and make the next recording At this time your own voice will be heard in the headphone automatically as side tone irrespective of the selection made for the monitor channel When you have completed the new recording press Replay S B once If you wish to hear and check this recording before putting it on line press Monitor S B followed by Replay S B when you will hear a single transmission of the new message If you wish to hear it again press Replay S B If the message is not correct or it is desired to record it again all that is necessary is to press Record again and carry on from the beginning of this section 5 of the instructions When satisfied with the new message press and hold the store control as well as the button for the other Store The led will illuminate dimly having accepted your request but the changeover to the new message will not take place until the previously running message has come to an end This fact will be signalled by the previous Store led being extinguished and the selected Store led changing from dim to full illumination Once a Store has been selected in this way the Radio Transmitter being used for the Atis Service will be automatically keyed to Transmit When any Store is on line the message will repeat constantly 6 MONITORI
4. circuit chip used in voice store for analogue to digital and vice versa conversion DRAM Dynamic Random Access Memory these are the components used to store the digital samples Jack Type B Post Office Jack Plug that conforms to gauge B BPO316 It has a smaller tip and ring than the conventional quarter inch jack plug see RENDAR SCHURTER type R22829000 Neutrik type NP3 TB B LED Light Emitting Diode XLR Generic name for a series of Audio Connectors originated by Cannon Electrics as their X series with Latch hence XL The R stood for rubber compound Audio engineers use XLR as a memory aid to the use of the three pin variant Where X pin 1 L pin2 Live and R pin3 Return of a balanced circuit User Manual Refreshed Datis type 6 Issue a da3man6a2 pdf Page 26
5. heard following an INHIBIT command User Manual Refreshed Datis type 6 Issue a da3man6a2 pdf Page 5 3 POWER SUPPLY The DATIS range of equipment use standard size plug in units according to the sub rack size so the DA3U6 has a 3U power unit This DA3U6 is fitted with an A C power source that has an auxiliary D C input The DA3U6 requires an input power source of nominally 230 volts A C which is fed to the power supply unit transformed down and rectified to provide the raw D C of 40 55 Volts to the secondary switcher The term secondary switcher refers to a switch mode power supply which does not operate on the mains input but rather that it uses a lower rectified voltage from the transformer secondary which is subsequently chopped by the switching transistor The D C input is stored by an electrolytic capacitor and is chopped by a VMOS power FET ata frequency of about 26KHz The output energy is controlled by varying the on time of the VMOS power FET Pulse Width Modulation and regulated by comparing it s output with a reference The plus five volt rail is the main regulated output the plus twelve is obtained by taking a step up tap on the output winding The auxiliary supply of negative five volts is generated from a separate winding on the ferrite cored transformer Isolation from earth is provided by the either mains or switching transformer or both dependant upon the power source in use which would all
6. of a new message A priority is assigned to the store that should be transmitting by placing a low on a BPR line The standby store has no priority and will accept a request for recording BPR Priority edge connector pin28 on store pcb A communication path for the two stores microprocessors is provided by PA6 on J2 pins of each store Itis a common line where either micro can pull the level low via the backplane wire or d principle When the transmitting announcer is sending text it will pull the line low the other announcer will be aware that text is being sent and will not start even if priority has been granted This is the method used to determine change over BARTEXT port PA6 edge connector pin8 on store pcb BRC Bar Record BRLD Bar rec lamp Pressing the record button causes a low on both announcers record lines simultaneously but the standby store has no priority it s BPR at PA4 will be high and will accept the request for recording The on line store should ignore the command since PA4 will be low BRC Bar Record edge connector pin30 on store pcb The record lamp is lit when text is being recorded into a store BRLD is driven via a diode by a 7406 o c driver from port PC5 The output is wired to edge connector pin16 on store pcb User Manual Refreshed Datis type 6 Issue a da3man6a2 pdf Page 18 8 1 VOICE STORE PORTS continued Inhibit cancelling a message The inhibit command requires a sing
7. operate normally Where the Aux D C option is employed and the equipment is to be switched off for any reason it will be necessary to first unplug the connector carrying the 24V D C Skt 2 Tr The printed circuit board on the right hand side S33145 is a 40 Watt isolated DC DC converter type the output is derived from a ferrite transformer allowing both auxiliary D C input terminals to float with respect to zero volts and chassis The pinout of the four way connector at the rear of the DA3U6 is as follows e e e User Manual Refreshed Datis type 6 Issue a da3man6a2 pdf Page 8 4 1 CONNECTION OF AUDIO LINES and TRANSMITTER Connections are made at the rear of the equipment via two Combo Jack sockets that accept either XLR or 5 25 stereo jack plugs Normal 5 25mm type B plug XLR Line 3 Line Line Line No Connection Line No Connection Ene The DA6U6 employed a type B jack plug which is not recommended for use in the combo jack although a rubber washer can be used to position the smaller gauge correctly so that contact is made the type B plug fits loosely The best connector is the XLR type which makes good use of the locking button on the combo jack At the rear of the DA3U6 are two Combo Jack Sockets one is for connection to the transmitter the other is an input which accepts an audio pair f
8. refreshed DA6U6 it is presented as a 3U height sub rack both this and it s predecessor the DA6U6 are operated at the front panel controls on the right hand side of the equipment 6 E There is a type 3B LEMO connector on the front panel for the user s headset The Alphanumeric Status Display has been rationalised on the DA3U6 design to indicate what the equipment is doing any any particular time The older DA6U6 has one display per voice store requiring that the user be more aware of how the equipment is intended to operate since the DA6U6 gives the status for both stores simultaneously The message text is recorded by the operator and is retained in a VOICE STORE when the message is recorded and checked it may be put into service as being the current information The P A Communications DATIS provides a continuous flow of spoken information by replaying a recorded message The process of storage and replay of the text involves NO MOVING PARTS NATO Stock No 5835 99 378 4854 There are TWO IDENTICAL voice stores contained within the equipment One of the two stores is selected for providing the message for transmission and is termed the ONLINE STORE the other store is available for preparation of further messages without disturbi
9. to provide a test signal to the transmitter albeit at a low level The LED indicators in each switch are provided in addition to the Alphanumeric display on the DA3U6 Other types of Datis are remote controlled with the same switch panel at a different remote location from the main equipment In that case the LED indicators provide confirmation of what function has been selected The DATIS is controlled by press button switches momentary make when pressed sending plus twelve volt signals to the Datis Logic The twelve volt pulse is level converted by opto isolators and the majority of the incoming commands are interpreted by the CMOS logic The controls may be grouped as follows Store Selection Monitor Selection Record Replay The first three control groups have registers that remember what button has been pressed Requests for Record and Replay are not stored by the Datis Logic but dealt with directly by the voice stores own logic The registers for Inhibit and direct are located on the Transmitter interface board Store Selection Three press buttons perform this function Store One Store Two and Off Pressing a store selection causes an SR type flip flop on Datis Logic to change state resulting in a bar priority line going low zero volts the priority signal is an active logic low and hence termed BAR PRIORITY which is output to the lower backplane The Datis Logic causes bar priority one to go low zero volts
10. when priority is requested for store one to replay to line Similarly for bar priority two and store two The OFF button cancels any request for priority causing both bar priority lines to go high five volts At power up the logic defaults to Stores Off Monitor Selection Three press buttons Mon Line Mon Standby and Mon Rx At power up the logic defaults to Monitor Line The action of pressing the desired button will cancel the previous selection The outputs from this group are termed BLL BLSB and BLRX respectively i e BLL bar listen line etc Record and Replay Standby These are single press functions without logic gates on the Datis Logic they become inverted and level shifted to five volts User Manual Refreshed Datis type 6 Issue a da3man6a2 pdf Page 12 6 OPERATING INSTRUCTIONS Ensure that the headset is plugged into the LEMO socket and the DA3U6 is switched On 1 MAKE THE FIRST RECORDING Press and momentarily hold the Record button for about half a second upon release recording will commence The Alphanumeric Display shows Once the record button is released a test message may be spoken into the headset microphone e g This is a test broadcast testing one two three four 2 When your message is completed press and release Replay S B and the RECORD led will extinguish Assuming that this is the first recording into an empty machine the test message will be
11. NG The operator may select at will the signal he wishes to monitor in his headset from the selection Line S B or Rx radio receiver if connected Whatever choice has been made it will be temporarily suspended each time the Record is selected In this mode the only signal the operator can hear is his or her own voice making the fresh recording When recording is terminated the monitor function reverts to that previously selected During normal operation signals will always be heard if either Monitor Line or Monitor Rx if fitted are selected When Monitor S B is selected signals will only be heard for one message cycle if Replay S B is pressed otherwise this source will be silent User Manual Refreshed Datis type 6 Issue a da3man6a2 pdf Page 14 6 2 7 TO CLOSE DOWN SYSTEM a TEMPORARILY FOR AN OPERATIONAL REASON Press the button Stores Off It will illuminate dimly having accepted your request and only come to full brilliance when the currently running message has finished In this mode the alarm will be disabled and the transmitter key will be released If the shut down is of short duration and or either of the stored messages is still valid the system may be restarted by selecting the appropriate Store to Line b FOR A LONGER PERIOD INCLUDING AT END OF WORKING DAY Press the button Stores Off as before To restart i If either message is still valid select the valid Store to Line ii If a
12. PA Communications Ltd Trinity Farm 28A Dunton Road Stewkley LEIGHTON BUZZARD LU7 OHZ U K Tel 01525 240945 Fax 01525 240063 CARING FOR THE S P A COMMUNICATIONS ANNOUNCER SYSTEM Model DATIS Type DA3U6 Refreshed Type Six Datis USER MANUAL This document describes the product fully Technical information has been included to provide interested readers with background to How it works engineering staff should find key information in each section that enables product support CONTENTS section INTRODUCTION and SYSTEM OVERVIEW 1 VOICE STORES 2 POWER SUPPLY 3 INSTALLATION and COMMISSIONING 4 CONTROLS 5 OPERATING INSTRUCTIONS 6 SIGNALLING AND BUSSING 7 VOICE STORE PORTS 8 AUDIO PATH 9 TELEPHONE LINE INTERFACE 10 CONNECTIONS 11 INDEX page Switch on and default status 10 Control Button Functions 11 Recording a message Checking a message 13 Recording to the Standby channel 14 Monitoring the messages 14 Close down 15 Fuses 6 7 22 24 Filename DA3MAN6a2 pdf Issue A 1 October 2010 revision2 User Manual Refreshed Datis type 6 Issue a da3man6a2 pdf Page 1 1 EQUIPMENT An Introduction DATIS DA3U6 is an ATIS recorder providing an Air Terminal Information System that uses digital recording and message playback techniques eliminating the wear and tear problems of mechanical systems and thus increasing the reliability and availability of the service The DA3U6 is the technically
13. Telephone line interface board G P15700 Status Module and Lock Switch H P15684 Switch panel controls Local Control Interface Datis Control J P15682 Remote Indicator Driver Behind H Notes A To remove the Power supply A from the sub rack the earth link should be unscrewed at the wing nut on the rear of the plug in unit J To remove the Remote Indicator Driver J from the sub rack it is first necessary to unscrew and extract the Datis Control plug in unit H User Manual Refreshed Datis type 6 Issue a da3man6a2 pdf Page 3 1 3 SYSTEM OVERVIEW continued Store1 Store2 Lo Audio Out ZO k RE c aos oi e e e e disisscasecess css era TESa E o e e e e e S a husn Tx Interface Datis Control The DATIS has two message stores allowing one store to be operational and the second to be prepared for the next message Changeover when initiated will occur at the completion of the message currently being transmitted Messages of up to two minutes in duration are recorded via the microphone of the operators headset and played back on continuous repeat until the operating requirements are changed The audio voice signals from the DATIS to the ATIS transmitter are continuously monitored and an alarm is given if the signal fails or dro
14. he interface answers the call by placing a low impedance loop across the telephone line off hook condition The audio signal the announcement text appears on the two wires of the telephone line as a balanced signal E B15327 TELEPHONE LINE INTERFACE Fuse 1 Set Tria Delay URL 9 2 160mA Fuse disconnection Barrier for Telephone Interface At the end of three messages the interface disconnects and reverts to a high impedance state with no D C path on hook condition In this respect it behaves as if it were a simple telephone as described in BS6317 A caller will hear the current transmission a maximum of two times following which the call will be disconnected by the DA3U6 If the message is being inhibited or there is no store selected to be transmitted Stores Off Line the telephone interface will not answer an incoming call User Manual Refreshed Datis type 6 Issue a da3man6a2 pdf Page 24 11 CONNECTIONS Connections are made to the rear of the equipment sub rack and are presented as the diagram below the numbering sequence follows the earlier DAGU6 3 7 e Rx 4 e co O N TX 1 230V A C Input IEC mains connector 24V D C Input Four pole Burndy 3 Rx Off air receiver Combo Jack Tx Radio Transmitter Combo Jack 1 X screen 2 L Live 3 R Return
15. ith automatic changeover between the dual input sources 2A F 5A F U neg5 200mA F FS3 FUSES locations and values There are three fuses on the DC DC convertor main board above and a further three on the rectifier board illustration below 200 mA F 3 15 A F 3 15 A F 6 ACinput 3 15AF Rectifier board inside left of PSU Module I External DC rues sma e g AC input Transformer secondary 3 15A Fuse 6 User Manual Refreshed Datis type 6 Issue a da3man6a2 pdf Page 7 4 INSTALLATION and COMMISSIONING CONNECTIONS The DA3U6 is contained in a 3U sub rack The user s headset plugs into the eight way LEMO connector on the front panel the other connectors are at the rear POWER The Main system is designed to operate from AC Mains supply of between 200 and 264 Volts 45 65 Hz The power should be connected via the plug in IEC receptacle on the rear panel using the plug in lead supplied The IEC receptacle on the rear panel accepts a 20mm fuse accessible when the lead is unplugged and should be fitted with a 3 15AM type AUXILIARY D C INPUT The D C power should be connected via the 4 way connector on the rear panel this is intended for the connection of a battery to maintain the system and protect the text during mains failure The neon lamp inside the mains switch will not be lit if the mains supply fails the aux D C will sustain the complete system all other indicators will
16. le button to be pressed the result of selecting this command is to energise relay RLE removing audio and breaking the transmitter keying The backplane carries the logic level to both voice stores edge conn pin 21 Voice store Port connected to edge connector pin monitors the logic level Bar Inhibit BIN If BIN is low the display will show Inhibit and will continue to scroll this message until the button is pressed a second time cancelling the BIN command The selected store will restart it s text spoken message from the beginning after Inhibit has been cancelled User Manual Refreshed Datis type 6 Issue a da3man6a2 pdf Page 19 9 AUDIO SIGNAL PATH I Switching Recording Buffer VOICE STORE 2 Vogad P L VOICE STORE 1 Standby Line Line Stby T X gt lt 12db Txf3 Rx Attn Rec Sidetone Monitor Channel Switching lt RX The Transmitter Interface connects the audio output of the selected store to the line amplifier which has a gain control located on it s front panel a screwdriver operated preset control used to set the audio level fed via transformer Txf 3 and to the line for the Radio Transmitter The range of this preset is nominally 20dB adjusting from neg 20 to plus 2 db The equipment leaves the factory set for neg 13db
17. ly designed for processing communication quality speech The sample so processed becomes an encoded number which is stored into memory It can be seen that the memory needs to be of sufficient size to accommodate the length of text that comprises the message The rate at which memory is used is 64 000 bits per second 64Kbps hence a message of around 64 seconds will fill one memory chip The microprocessor is used to store away the samples into the memory it is also used to recover the samples so that the waveform may be reconstructed when the message is to be replayed Hence a similar process to a tape recorder is taking place but doing so with no moving parts no tape nor wear to rotating parts or to any magnetic media Each announcer card has it s own operating software in the form of a plug in read only memory which is non volatile this is termed firmware i e it remains if power is disconnected The memory chips that are employed to store the message text are the volatile type known as Dynamic RAM which requires that the DA3U6 is kept powered to store the text When the DA3U6 is disconnected from the power source it will erase messages that have been previously recorded Both voice stores share in controlling the whole system the embedded control firmware is a vital part of that process and is unique to a particular type of Datis e g The DA3U6 control firmware observes the Bar Inhibit line to ensure that complete bulletins are
18. ng the online transmission and is referred to as the STANDBY STORE The press button switch panel is used both for preparing stored messages and to make the selection of which store should be Online Both the Audio Output and the off air input have telecommunications line interfaces approved for connection to B T in order that distant transmitter or receiver sites may be used 00000 0000 PA manufactures an accessory for Datis that expands the single Tx output providing two isolated transmitter keying pairs The Active Keying box can be powered from the db9 connector on the rear it consists of two identical transmitter keying interfaces each driven by it s own audio buffer amplifier to provide isolation and to allow compensation if different sensitivity transmitters are in use User Manual Refreshed Datis type 6 Issue a da3man6a2 pdf Page 2 1 2 SYSTEM OVERVIEW HEI A BC D E F G H Plug In Unit Part Number Description A 33145 Power supply which supplies plus five plus twelve and negative five volts B P15160 The first of two identical voice stores C P15160 The second of two identical voice stores D P15375 Transmitter Interface E P15460 Operator Audio Interface F P15327 Ring Trip
19. om the Monitor channel It is driven by a separate buffer amplifier so that the load of the headphones does not affect the level of signal transmitted to line The buffer amplifier gain which in turn sets the loudness of the headphones can be adjusted by a preset control on the Operator Audio Interface VR10 The three press buttons Mon Line Mon Standby and Mon Rx are used to select what is heard in the headphones The button press is stored by the Datis Logic and results in one of the following command lines being sent to a logic low These control signals are input to the Operator Audio Interface via a pin of it s edge connector Description edge pin no Bar Listen Line BLSB Bar Listen Standb BLRX Bar Listen Receive BRLD selects recording sidetone when in record mode The control signals are conditioned and each drives one element of U3 the CMOS transmission gate type CD4066 which turns on and connects the desired signal Attenuators are used on the two switch elements sap which select standby store and sidetone to normalise all four to the same level as set by Attn Rec VRQ to typically neg 13db Sidetone Monitor Channel Switching User Manual Refreshed Datis type 6 Issue a da3man6a2 pdf Page 21 Audio Boards Layout Transmitter Interface 9 2 L 7 z m o E a 3 Mo a z 0 0000000000
20. onnected together via the backplane and it is termed the BRLD buss When control signals are sent via the lower backplane they are generally active logic low i e bar type signals OV true User Manual Refreshed Datis type 6 Issue a da3man6a2 pdf Page 16 7 1 INTERNAL SIGNALLING amp BUSSING continued The audio output from the voice store that is online is selected and amplified by the Transmitter Interface User Manual Refreshed Datis type 6 Issue a da3man6a2 pdf Page 17 8 VOICE STORE PORTS The system functions by reaction to certain ports of the announcer s microprocessor called INPUT PORTS causing other ports called OUTPUT PORTS to change state BPLAY Bar Play The bar play command has two functions to terminate a recording and to replay the standby store BPLAY Bar Play port PC2 edge connector pin BRV Bar Review The bar review signal goes low while a voice store is replaying but not to line it is used to drive the green indicator in the Replay S B button BOL Bar On line A signal is required to activate the line relays one per store the signal is called BOL Bar On line and is driven low when valid text should be transmitted to line BOL on line edge connector pin29 on voice store pcb BPR Bar Priority and BARTEXT Where 1 or 2 dependant upon store The announcers are configured as two stores one for transmission to line and the other as a standby for updating and preparation
21. operator s headset Mon itor Press Ten of the press button indicators are fed Lo iC from thirteen constant current indicator g Button drivers three of which provide low level illumination Interface Datis Control The two identical voice stores receive commands via the backplane the transmitter interface provides the audio switching selecting the audio from the voice store that is online The Operator Audio Interface contains the Monitor Channel Audio switching as well as the recording microphone pre amplifier The Datis Control provides the majority of the user interface from the set of press buttons Backplane Common Routes An example of common routes are the three power supply rails 5 12 5 volts which are used to power the plug in units they connect at each edge connector on the same pin number the PSU socket differs marginally There are also designated control pins Es on on the voice store which are connected to the microprocessor these control pins 0 Volt rail are routed by the backplane and each Plus 5V 1 pin has a buss name in addition to it s 2 actual pin number 4 Neg 5V 5 Where possible a particular pin number Nominal Pils Tay is reserved for it s particular function and it 31 Plus 5V is reserved at all plug in slots 32 0 Volt rail e g BRLD at pin 16 excluding the power supply socket position and the transmitter interface all pins 16 are c
22. ow the zero volt terminal of the power supply to be internally connected to both mains earth and chassis an RC network of 1KO and 100n in parallel is provided as this link to minimise pick up of mains hum and noise while recording FUSES locations and values On rear of DA3U6 Mains fuse inside IEC receptacle 20mm type 3 15 AM Both the mains power and earth bonding link should be removed from the rear before removing the PSU then unscrew the four front panel screws of the plug in unit LA and withdraw at the front The DA3U6 plug in unit has its mains transformer fitted in the left hand module together with the DC input switching diodes and raw supply components on the rectifier board The DC to DC converter printed circuit board slides into a second set of card guides to the right of this but the whole assembly is withdrawn as one plug in unit The left hand module extends to the rear of the equipment sub rack and houses both of the power input receptacles In addition to the mains fuse that is positioned inside the IEC receptacle drawer there are three fuses on the rectifier board and a further three on the DC DC convertor main board User Manual Refreshed Datis type 6 Issue a da3man6a2 pdf Page 6 3 1 POWER SUPPLY continued The DA3U6 employs a single plug in module power supply unit accepting both A C and D C input power offering ground isolation from either power source w
23. ps to a low level 1 4 Features of the Type DA3U6 DATIS Equipment practice Standard Euro cards installed in a 19 inch sub rack housing 3U height plug in units Card depth 160mm Equipment operation By means of front panel controls Momentary press button switches Length of announcements Either channel each has a maximum text capacity of 128 seconds Coding of signals Standard A law companding code following CCITT Vol III 2 Rec G 711 712 733 64K bit sec Frequency range 300 3400Hz 3db Signal to noise ratio neg 45 to neg 50db Distortion less than 3 Temperature range Operation 0 C 50 C Storage 20 C 80 C Audio Output Balanced output isolated by line transformer Impedance 600 Ohm Level adjustable from 20 to Odb Power requirements 230 V AC or 10 Mains Frequency 47 63 Hz with aux D C 24V backup input Power Consumption 10 Watts User Manual Refreshed Datis type 6 Issue a da3man6a2 pdf Page 4 2 VOICE STORES The variable text voice store cards used in the m mm o equipment are two identical 3U plug in units gt e e e Each has a control microprocessor which is used e to manage the storage and recovery of digital samples The samples are stored in text memory at a rate of 8000 per second The signal to be recorded is sampled and quantised according to CCITT A Law which is specifical
24. recorded into both stores simultaneously 3 CHECKING PLAYBACK After having finished recording as described in steps 1 2 above press Monitor S B and then press Replay S B 3a 3b The message that has been recorded can now be checked by listening with the headset prior to sending it to Line 3c Press Monitor Line in preparation for the next step 4 GOING ON LINE The store that is assigned priority will replay it s message to line Select Store One by pressing and holding Store control and Store 1 to Line The test message will be transmitted over the radio The display will show The message can be heard in the headphone and will repeat itself continuously 3c 3a NFR 3b If the message being repeated is satisfactory and is to be left running no further action is required Should you no longer wish to hear the message in the headphone pressing Monitor S B will produce the desired silence User Manual Refreshed Datis type 6 Issue a da3man6a2 pdf Page 13 6 1 5 TO MAKE SECOND AND SUBSEQUENT RECORDINGS
25. rom a monitor receiver this signal is fed to the Operator Audio Interface via it s own fuse disconnection barrier RX input for audio from off air receiver TX output to transmitter The Audio Output is designed to key the transmitter using the audio pair When the transmitter is required to send TX ON either RLA or RLB contacts provides a low resistance loop o The audio output transformer has a split secondary which has the A C circuit completed with a 2u2 capacitor The contacts of RLC are used to key the transmitter by placing a short across the 2u2 capacitor LE be The Transmitter interface plug in unit has a screwdriver operated preset control on it s front panel this is used to set the audio level sent down the line to the Transmitter The range of this preset is nominally 20dB adjusting from neg 20 to plus 2 db The equipment leaves the factory set for neg 13db User Manual Refreshed Datis type 6 Issue a da3man6a2 pdf Page 9 4 2 INSTALLATION PRELIMINARY TESTS On the extreme left of the subrack front panel a led marked ON indicates the presence of power to the system once it has been switched on with the rocker type power switch During initialise a message will scroll through the display that denotes the model number The display then shows the words NO TEXT indicating that both voice stores are empty until such a time as the fi
26. rst recording is made INDICATORS Voice Stores Each voice store has two leds to show it s status GREEN Play led e RED Record led A Store in use is indicated by a green led on it s front panel a corresponding red led being illuminated indicates that the particular Store is in the process of being updated and is in the Record mode Power Supply RED indicates Input Power ON GREEN plus twelve rail O K GREEN plus five rail O K E GREEN neg five rail O K User Manual Refreshed Datis type 6 Issue a da3man6a2 pdf Page 10 5 Control Button functions There are twelve Illuminated push button control switches in two columns they can be grouped by function lI 1 STORE SELECTION Datis Output elle ae e e MONITOR SELECTION Headset Signal 3 MESSAGE CONTROL Message Recording and check N 4 DATIS CONTROL Executive Control Group 1 STORE 1 TO LINE Selects message 1 for transmission STORE 2 TO LINE Selects message 2 for transmission STORES OFF Disconnects both stores from Datis output The store selection controls the priority of the transmitted message Note that the three controls are interlocked with the lower button of group 4 the STORE CONTROL Datis operation requires that STORE CONTROL be held down while the
27. s is more likely neither message is valid proceed to the beginning of these Instructions to the section To make First recording note i If encountering a DA6U6 with either no text or with old messages in both stores some users have found it useful to erase both stores by selecting Stores Off and then recording a few moments of silence or the words Test Transmission or both note ii If the record button is pressed momentarily by chance and is less time than a normal press bearing in mind the closeness of the Store Control button the record mode entry delay allows the operator to change their mind by removing finger or thumb without accidentally erasing the standby message User Manual Refreshed Datis type 6 Issue a da3man6a2 pdf Page 15 7 INTERNAL SIGNALLING amp BUSSING The DA3U6 has a Datis control logic board attached to the rear of the switch panel at the right hand side of the sub rack pressing a switch on this panel causes the Datis control logic to issue a command onto the Announcer Buss Control which is a bi directional parallel arrangement connected via specific tracks of the backplane There are two main registers the tap that determines whic p t indicator PRIORITY LOGIC that d hich riori y D of the two voice stores has priority for broadcasting it s message 13 and the MONITOR LOGIC that selects the audio signal that is heard in the
28. selection is made Group 4 The Store Control button has a red indicator that lights while eM the lock switch is in the ACCESSED position If the controls are LOCKED this led is extinguished INHIBIT Disconnects all output signals from the unit DIRECT Allows transmission of messages direct from B O the headset microphone Interlocked with Store Control STORE Interlock button to prevent accidental CONTROL operational changes Group 3 MONITOR LINE RECORD RECORD Records headset microphone voice message to the store not selected Note that if both stores are off the same message goes to both stores S B REPLAY S B Used to end recording and to Replay the message on the standby channel 2 lus LAMP TEST Checks all button lamps when pressed Group 2 MONITOR LINE Outgoing Datis message to headset MONITOR STANDBY Standby message to headset MONITOR R X Datis channel VHF receiver to headset User Manual Refreshed Datis type 6 Issue a da3man6a2 pdf Page 11 5 1 CONTROLS and equipment reaction to controls DIRECT when used in conjunction with the STORE CONTROL button is used in a type five datis and connects the microphone output direct to the audio buffer that feeds the transmitter The DA6U6 is a type six datis the microphone on the headset has insufficient output drive for this function The DA3U6 has additional amplification to allow this facility
29. sora 72 a Stet oko ua o s OB E Es bu a o b 8 E oo 83 Sie Tar k C o om E E ms uu 0000000 J 0 Et oh 4 o dO ms a ces c36 i oo Ra oo To T cia R64 oD To D8 OF D E Eq S cc v 19 o sa E Ko e o jo oo eap el g im Poses Jie seep S el Te ES O Sete at ol o e ema fe 4 990000000 maol S zao 000000000 GG o E cs m Ql O j SE SOCO DOOM O Page 22 da3man6a2 pdf User Manual Refreshed Datis type 6 Issue a User Manual Refreshed Datis type 6 Issue a da3man6a2 pdf Page 23 10 TELEPHONE LINE INTERFACE The Audio Output for transmission and the off air receiver input have telecommunications line interfaces approved by B T in order that distant transmitter or receiver sites may be used The Tx interface is on plug in unit D the Rx is on plug in unit D TELEPHONE ACCESS TO MESSAGE A separate line interface is provided presented as a two wire connection on a pins 2 and 5 of a standard U K telephone cord which can be plugged into an analogue P A B X port or into a 431 jack being a Network Termination Point of the P S T N Public Switched Telephone Network operated by British Telecom Mercury and the City of Hull When 75V 25Hz ringing current is offered to the interface it is applied to the ringing current detector which has an A C input impedance in excess of 5 000 ohms T
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