Successfully reported this slideshow.

ASL Intercom PS 279


Published on

Published in: Health & Medicine, Business
  • Be the first to comment

  • Be the first to like this

ASL Intercom PS 279

  1. 1. PRO SERIES USER MANUAL FOR THE PS 279 DUAL CHANNEL MASTER STATION CONTENTS 1.0 SAFETY INSTRUCTIONS……………………………….3 2.0 GENERAL DESCRIPTION ......................................... 4 3.0 UNPACKING .............................................................. 4 4.0 MECHANICAL INSTALLATION .................................. 4 5.0 MAINS POWER.......................................................... 5 6.0 FRONT PANEL CONTROLS ...................................... 6 7.0 REAR PANEL CONTROLS ........................................ 8 8.0 INTERNAL CONTROLS ............................................. 9 9.0 CABLING.................................................................. 10 10.0 PARTY LINE, TECHNICAL CONCEPT .................... 11 11.0 WARRANTY ............................................................. 11 12.0 DESIGN CRITERIA .................................................. 11 13.0 TECHNICAL SPECIFICATIONS............................... 12User Manual PS 279 / Issue 1 © 2006 ASL Intercom, Utrecht, The Netherlands.
  2. 2. 2 User manual PS 279 / Issue 1 © 2006 ASL Intercom, Utrecht, The Netherlands
  3. 3. 1.0 IMPORTANT SAFETY INSTRUCTIONS ! Please always follow these instructions to help ensure against injury to yourself and damage to the system. 1) Read all safety and operating instructions 11) Insert the plug properly. Do not defeat the before you operate the apparatus. safety purpose of the polarized or grounding- type plug. 2) Retain all safety and operating instructions for A polarized AC line plug has two blades with future reference. one wider than the other. This plug will fit into the power outlet only one way. This is a safety 3) Heed all warnings on the apparatus and in the feature. If you are unable to insert the plug fully safety and operating instructions. into the outlet, try reversing the plug. If the plug still fails to fit, contact an electrician to replace 4) Follow all installation, operating and use the obsolete outlet. instructions. A grounding type plug has two blades and a third grounding prong. The wide blade or the 5) Unplug the apparatus from the AC power third prong are provided for your safety. If the outlet before cleaning. Use only a damp cloth provided plug does not fit into your outlet, for cleaning the exterior of the apparatus. consult an electrician to replace the obsolete outlet. 6) Do not use accessories or attachments not recommended by the manufacturer, as they 12) Route power supply cords so that they are not may cause hazards and void the warranty. likely to be walked on or pinched by items placed upon or against them. Pay particular attention to cords at plugs, convenience 7) Do not operate this apparatus in high receptacles, and the point where they exit from humidity areas or expose it to water or the apparatus. moisture. 13) Do not overload wall outlets or extension 8) Do not place the apparatus on an unstable cords, as this can result in a risk of fire or cart, stand, tripod, bracket or table. The electrical shock. apparatus may fall, causing serious personal injury and damage to the apparatus. 14) Unplug this apparatus during lightning storms or when unused for long periods of time. 9) Do not block or cover any openings in the apparatus. These are provided for ventilation and protection from overheating. 15) Never insert objects of any kind into the Never place the apparatus near any heat apparatus through openings, as the objects sources such as radiators, heat registers, may touch dangerous voltage points or short stoves, or other apparatus (including out parts. This could cause fire or electrical amplifiers) that produce heat. Do not place the shock. apparatus in an enclosure such as a cabinet without proper ventilation. 16) Refer all servicing to qualified service personnel. Servicing is required when the 10) Operate the apparatus using only the type of apparatus has been damaged in any way, such power source indicated on the marking label. as when the power-supply cord or plug is Unplug the apparatus’ power cord by gripping damaged, liquid has been spilled or objects the power plug, not the cord. have fallen into the apparatus, the apparatus has been exposed to rain or moisture, does not operate normally, or has been dropped.User manual PS 279 / Issue 1 © 2006 ASL Intercom, Utrecht, The Netherlands 3
  4. 4. 2.0 GENERAL DESCRIPTION The PS 279 is designed to be a master unit in an ASL Special attention has been paid to the intelligibility of intercom system and can be used in portable as well as speech. By applying low noise/high speed circuitry, a fixed applications. It incorporates a dual channel intercom speech presence filter and a specially designed high line power supply with auxiliary input, a dual channel power headphone amplifier, communication is very headset station and uses only 1U of 19” rack space. comfortable even in environments with a high background noise level. This makes the PS 279 very versatile and ideal for use in applications where standard microphone cable is available The unique CALL system provides both a flashing red and ease of setup is of paramount importance. LED and a very distinctive and characteristic sound signal. Only a short push of the CALL button will make the LED Each channel has a Volume (listen level) control, a Talk flash. The Call sound signal (buzzer) will be activated and a Call button with LED indicators and a side tone when holding the button for two seconds. In case the trimmer. sound signal is undesirable, all buzzers can be muted with the “All buzzers on/off” button. The intercom line power supply is fully protected and can drive at least 20 beltpacks operating at full power. Fully electronic switching increases reliability and allows The power supply is completely separated from all other for: functions and in case of power failure, the unit will accept - “soft” microphone ON switching, latched or momentary line power from an external ASL power supply. - remote Mic Mute facility. All microphones of stations connected to the PS 279 can be muted by pushing a Since the power supply provides the line impedance, one single front button. would generally only use one PS 279 on a 2-channel Intercom system. An Aux input at the rear panel allows injecting external Should you want to connect a PS 279 to another audio signals at line level. Intercom system, the ‘System link’ connector at the back An Aux signal can be routed to intercom line A and/or B, of the unit has to be used to avoid impedance problems. or directly to the local headset. If the number of beltpacks/speaker stations exceed the capacity of the PS 279 power supply, a booster power As an option, an XLR-6 headset connector can be fitted, supply (PS 285) can be used. allowing the user to hear channel A + AUX program signal on the left headset can and channel B + AUX program signal on the right headset can. By changing the position of internally mounted jumpers, it’s also possible to hear channel A + B on the left can and the AUX program signal on the right can .3.0 UNPACKING The shipping carton contains the parts listed below ASL has taken great care to ensure that this product * The PS 279 reaches you in flawless condition. * Mains power cable After unpacking the unit, please inspect for any physical * Spare fuses damage to the unit, and retain the shipping carton and * User manual relevant packing materials for use should the unit need returning. If any are missing, contact your dealer. If any damage has occurred, please notify your dealer With the PS 279 will be a small packet of spare fuses. immediately so that a written claim can be initiated. Please keep them in a safe place. Please also refer to the guarantee section of this manual. There is also one spare fuse included in the mains inlet.4.0 MECHANICAL INSTALLATION A vertical rack space of 1U (1.75”, 44mm) is required for The power unit is mounted on the bottom of the unit, and the PS 279. It is not necessary to provide rear support by after a period of time it will feel hot to the touch on top extra bracing or shelving. and bottom. This is normal, and should be no cause for alarm Adequate ventilation must be provided by allowing sufficient space around the sides and rear of the unit to ensure free circulation of air. Forced cooling is not required.4 User manual PS 279 / Issue 1 © 2006 ASL Intercom, Utrecht, The Netherlands
  5. 5. 5.0 MAINS POWER The PS 279 may be connected to the mains power outlet As the colours of the wires in the mains lead may not to which other audio equipment is connected. The outlet correspond with the coloured markings identifying the should have a clean earth. Avoid using mains power terminals in your plug, proceed as follows: outlets, which also power dimmer controlled lighting equipment. - The wire that is coloured green-and-yellow must be connected to the terminal in the plug, which is Before connecting the unit to its AC power source, check marked with the letter “E”, or by the ground if the mains voltage of the unit (100 V – 240 V) is in symbol, or is coloured green. accordance with your local mains voltage. - The wire that is coloured blue must be connected to the terminal that is marked with the letter “N” or coloured black. WARNING - The wire that is coloured brown must be This appliance must be earthed connected to the terminal that is marked with the letter “L” or coloured red. Those units that are supplied to the North American IMPORTANT market will have an integral moulded 3-pin connector, The wires in this mains lead are colour coded in which is provided to satisfy required local standards. accordance with the following code: green and yellow / safety ground blue / neutral brown / live5.1 SAFETY EARTHING The green-and-yellow wire of the mains cord must always might be mounted shall be connected to the same be connected to the electrical installation safety earth or grounding circuit. ground. It is essential for personal safety as well as for proper operation of the PS 279 and the other connected The PS 279 employs professionally designed audio input stations. This wire is internally connected to all exposed and output circuits which do not require the disconnection metal surfaces. Any rack framework into which this unit of any safety earth for the avoidance of hum loops.5.2 POWERING UP Powering up procedure: - Make sure that the red power switch on the left side of - Turn on the power with the red button. The red the front panel is OFF. overload LED will light up for about 3 seconds, then - Connect the power cord to the rear of the station. extinguishes and the green power LED will switch on, - Plug the other end of the power cord into a indicating the station is active. PROPERLY GROUNDED outlet. See for further installation and operation the concerning sections.5.3 MAINS POWER SETTING The unit has a switch mode power supply and accepts mains voltages from 100 – 240 VAC (50 / 60 Hz). Mains Fuse For all voltages : T 1250.User manual PS 279 / Issue 1 © 2006 ASL Intercom, Utrecht, The Netherlands 5
  6. 6. 6.0 FRONT PANEL CONTROLS AND CONNECTOR 1 POWER ON/OFF switch 6 BUZZER Mains power push button for switching the internal This buzzer indicates an incoming or outgoing call. It is power supply ON and OFF. activated by pressing a CALL button of the PS 279 or a CALL button on any other station on channel A or B 2 OVERLOAD LED for longer than two seconds, if the buzzers are not This LED illuminates, when the internal circuit-breaker muted (see 5.7). You can adjust its volume with the shuts off line power due to overload. A cause for buzzer volume control. overload can be a connection of too many user stations, a short-circuit in the interconnecting cables, 7 BUZZER VOLUME trimmer or a thermal overload. The circuit-breaker resets This trimmer adjusts the volume of the buzzer. automatically 3 seconds after the cause of the overload has been removed, and restores line power 8 ALL MIC’S ON/OFF button automatically. With this pushbutton all microphones of the connected During short-circuit, the LED will flash every 3 stations can be switched off. Each user station can seconds. During thermal overload it will be lit activate its microphone again by pushing its TALK continuously. button. The LED will also come on for a few seconds every time you switch on mains power. 9 ALL BUZZERS ON/OFF button With this button all buzzers of the connected stations 3 POWER LED can be muted. The buzzers stay muted until the Mute This LED illuminates if line power is supplied by the button is switched off again. internal power supply. 10 AUX VOLUME controls 4 SYSTEM LINK IN A These knobs adjust the level of the Aux input signal to This LED illuminates if another ASL Intercom System each of the two intercom lines. has been connected to the PS 279 through the “System Link” connector of Channel A. The Line 11 A/B/HEADSET routing switches Impedance is now provided by the other Intercom These three switches route the aux input signal to system and the internal line impedance for Channel A either: is switched off. The Buzzer mute function on Channel 1) Intercom channel A and/or Intercom channel B A can now only be controlled by the connected 2) Directly to the headset system, while the Buzzer Mute on Channel B will still be controlled by the PS 279. The Mic Mute signals If the aux is routed to the headset it is for local given by the other Intercom system are also sent to monitoring only, and cannot be routed to the intercom the user stations connected to Channel A of the PS channels. 279. If a Mic Mute is given by the PS 279, it is only send to its own channels and does not mute the microphones of the other Intercom System. 5 SYSTEM LINK IN B This LED illuminates if another ASL Intercom System has been connected to the PS 279 through the “System Link” connector of Channel B. The Line Impedance is now provided by the other Intercom system and the internal line impedance for Channel B is switched off. The Buzzer mute function on Channel B can now only be controlled by the connected system, while the Buzzer Mute on Channel A will still be controlled by the PS 279. The Mic Mute signals given by the other Intercom system are also sent to the user stations connected to Channel B of the PS 279. If a Mic Mute is given by the PS 279, it is only send to its own channels and does not mute the microphones of the other Intercom System.6 User manual PS 279 / Issue 1 © 2006 ASL Intercom, Utrecht, The Netherlands
  7. 7. 6.0 FRONT PANEL CONTROLS AND CONNECTOR 12 VOLUME control knobs 15 CALL A & B buttons These knobs adjust the listen level of the headset. These push buttons activate the CALL system. A Each channel can be adjusted separately. momentary push will send a visual CALL signal to all stations connected to that intercom channel and the 13 SIDETONE trimmers CALL LEDS will start flashing. These trimmers adjust the level of your own voice as When holding the buttons pressed for 2 seconds, the you hear it in your headset. buzzer will be activated. Adjustment procedure: After the CALL button is released the LEDS will - set the trimmer in start position: fully clockwise. continue to flash for further 2 seconds. - switch off the microphone of all connected (speaker!) stations. 16 HEADSET connector - switch on the microphone of the required channel. A XLR-4 type connector to connect the local headset. - turn up the volume of the required channel. The headset-can must have an impedance of 200 - speak into the headset microphone. ohms or greater, or each 400 ohms minimum when in - adjust the listen level by turning the sidetone parallel. The mic may be of the dynamic or electret trimmer. type. The operating area is between fully clockwise and minimum level. Adjusting the sidetone does not affect Pin assignments: the level of your voice as it is heard by other stations. 1. shield mic. (GND) 2. mic. + 14 TALK buttons 3. phones + These buttons allow you to talk to each channel 4. phones – separately or simultaneously. The large green LED is lit when the talk function is The wiring is such that both headset cans are connected activated. in parallel and receive the same signal. The two headphone amplifiers run in a bridged mode. Latched switching: When a TALK button is pressed shortly, the As an option, an XLR-6 type connector can be fitted to microphone of the chosen channel will be switched on allow a binaural headset configuration where a different and latches electronically. When pressed again, the signal will appear on each can. In this mode the internal microphone will switch off. headphone amplifiers are not bridged. See section 7.1 Internal Jumpers and Controls. Momentary switching: When holding a TALK button pressed while talking, the microphone will remain switched on until the button is released. Then the microphone will switch off automatically.User manual PS 279 / Issue 1 © 2006 ASL Intercom, Utrecht, The Netherlands 7
  8. 8. 7.0 REAR PANEL CONTROLS AND CONNECTOR 17 A & B LINE connectors 21 MAINS INLET / DISCONNECT DEVICE These XLR-3 type connectors are for connecting the IEC Mains connector. For correct wiring and operation remote-stations, via standard microphone cable. There refer to section 4.0. are two connectors for channel A and two connectors for channel B. WARNING Pin assignments: Before you plug in the mains voltage, check if: 1. 0V / ground shield * The fuse is correct 2. +30V power wire * The voltage is correct 3. audio wire 18 SYSTEM LINK IN connector Input for the cable of an external party-line Intercom 22 FUSE system. If one or both channels of the PS 279 are to This fuse protects the PS 279 against severe internal be connected to another intercom system then these damage, in case of malfunction in the power section. connectors will accept the communication signals from To remove the fuse the mains cord must be removed. the other system. It is most important to place the correct fuse in the 19 AUX INPUT connector holder: This XLR-3 type aux input connector is electronically balanced and accepts audio levels between –20dBu to Mains voltage fuse +21dBu on line level. 100 – 240 VAC T 1250 mA Pin assignments: Spare fuses are supplied with the unit. 1. 0V / ground 2. signal + 23 DC INPUT connectors 3. signal - These connectors can be used as a backup power supply or when no 100/240 VAC voltage supply is 20 GROUND LIFT switch available. They accept 12 – 28 VDC. With this switch the pin 1 of the AUX input XLR is lifted from ground when in “Lift” position.8 User manual PS 279 / Issue 1 © 2006 ASL Intercom, Utrecht, The Netherlands
  9. 9. 8.0 INTERNAL CONTROLS MIC GAIN The setting of the mic gain must be done by qualified service personnel only ! The mic gain is adjusted internally. - To reach the mic gain, undo the two screws at the front panel of the PS 279 and the two screws on the top side. - The trimmer is located at the right front of the unit. - To increase mic gain turn counter clockwise. - To decrease mic gain turn clockwise. See section 7.1 for the location of the mic gain trimmer.8.1 INTERNAL JUMPER SETTINGS AND CONTROLS BINAURAL JUMPER SETTINGS The setting of the binaural jumpers must be done by qualified service personnel only ! See also section 5.16 HEADSET connector, an XLR-6 is a must for binaural operation. The binaural configuration is set by internal jumpers J3, as follows: Jumpers in position A: Left can Channel A and B. Right can AUX signal. Jumpers in position B: Left can Channel A and AUX signal Right can Channel B and AUX signal Internal mic gain See also section 7.0 Internal controls. The mic gain trimmer is labeled: P2 for the mic gain setting.User manual PS 279 / Issue 1 © 2006 ASL Intercom, Utrecht, The Netherlands 9
  10. 10. 9.0 CABLING For the PRO Series Intercom system the interconnecting cables are of the shielded two-conductor microphone cable type and the intercom line connectors are of the XLR-3 type. Audio and Call signals are on XLR pin 3, DC power is on XLR pin 2. XLR pin 1 is connected to the shield of the cable, which functions as the common return for audio and power. Since the audio signal is transferred in an unbalanced way, certain rules have to be obeyed when installing the cables of an intercom network. This is to avoid earth loops and to minimize power loss and the possible effect of electromagnetic fields. These rules are: • Use high quality (multipair) cable. • Keep cables parallel as much as possible For interconnecting user stations, power supplies When two (multi channel) units in a network are and accessories in an ASL Intercom network, use connected by more than one cable, make sure that high quality shielded two-conductor (minimum these cables are parallel to each other over the size 2 x 0.226 mm² (#24AWG)). microphone whole distance between those units. When using cable only. multi pair cable, parallelism is ensured in the best In case of a multi channel intercom network, use possible way. high quality microphone multipair cable only, each pair consisting of two conductors (minimum • Avoid closed loops. 2x 0.15 mm2) with separate shield. Multipair Always avoid that cables are making a loop. So- cable should also have an overall shield. called ring intercom should not physically be cabled as a ring. All cable routes should have a star • Use flexible cables. configuration, with the central earthing point (usually Use flexible single and multipair microphone close to the power supply position) as the centre of cable instead of cable with solid cores, especially the star. when the cable is subjected to bending during operation or installation. • Keep cables away from electromagnetic sources. Keep intercom cables away from high-energy cables, • Separate cable screen to XLR pin 1. e.g. 110/220/380V mains power or dimmer controlled The screen of each separate microphone cable feeds for spotlights. and/or the screen of each single pair in a Intercom cables should cross high-energy cables at multipair cable should be connected to pin 1 of an angle of 90° only. each XLR-3 connector. Do not connect this cable Intercom cables should never be in the same screen to the metal housing of the connector or to trunking as energy cables. metal wall boxes (outlets). See page 12 for Earthing Concept. • Place power supplies in a central position. In order to avoid unacceptable power losses, place • Cable trunks, connection boxes and overall the power supplies as close as possible to where multipair cable screen to clean earth. most power consumption occurs or, in other words, Metal cable trunks, metal connection boxes and most user stations are placed. overall multipair cable screen should be inter- connected and, at one point (the central earthing • Connect ASL power supply to a clean mains point) in the intercom network only, be connected outlet. to a clean safety earth. The ASL power supply may be connected to the See page 12 for Earthing Concept. mains power outlet to which other audio equipment is connected. Avoid using mains outlets which also • Keep metal connection boxes and cable trunks power dimmer controlled lighting systems. isolated from other metal parts. Metal housings for intercom cables and connectors In case of more complex installations, dont hesitate to should be mounted in such a way that they are contact us. Please send us a block diagram of the isolated from other metal cable and connector planned network with a list of all user stations and their housings and from any other metal construction positions, and we are happy to advise you on cabling parts. layout. See Party Line, Technical Concept10 User manual PS 279 / Issue 1 © 2006 ASL Intercom, Utrecht, The Netherlands
  11. 11. 10.0 PARTY LINE, TECHNICAL CONCEPT 12.0 DESIGN CRITERIA ASLs PRO Series offers a complete, two way (full Applications / Environment of use duplex) communication system. ASL Pro Series equipment is designed for use as a Users of the system are connected via a party line. wired communications system in theatres, in Radio/TV Master stations (with built-in power supply), beltpacks, production facilities, in factories, and in utilities speaker stations and power supplies are interconnected complexes such as airports, railway stations and coach via standard microphone cable (minimum cable size of 2 terminals. x 0.226 mm² (#24AWG)). One wire is used as an audio line, one as a power line and the screen of the cable ASL equipment can be used outdoors in normal functions as earth/return. weather conditions. In conditions with excessive cold (<-10° C), heat (>50° C) or humidity (>85%), ASL Current drive is used for signal transfer. Each station equipment might not perform properly. utilises a current amplifier to amplify the microphone signal and place it on the common audio line where, due ASL equipment is not designed to be used under to the constant line impedance (situated in the power water, or in situations where explosion safe equipment supply between XLR pin 3 and 1), a signal voltage is is specified by authorities. developed which can be further amplified and sent to headphones or loudspeakers. Emission ASL Pro Series equipment does not generate high This principle has three advantages: frequency (HF) signals. An ASL power supply can generate a weak magnetic field caused by the power - the use of a single audio line allows several stations transformer. To avoid possible negative affects, keep to talk and listen simultaneously. ASL power supplies at a safe distance from equipment - due to the high bridging impedance offered by each which is very sensitive to magnetic fields. station, the number of stations on line has no influence on the level of the communications signal. Immunity - power and audio to the intercom stations use the ASL Pro Series is designed on the base of low same cable. impedance signal transport. User stations and power supplies are to be connected via low capacity cabling The Call signal is also sent as a current on the audio with an overall screen (also see Cabling section). line. It develops a DC potential over the line impedance Therefore, HF signals are adequately rejected to that will be sensed by each station and interpreted as a maintain an intelligible communication, unless strong Call signal. electro-magnetic fields (exceeding 3 V/m) are in the direct vicinity of the interconnecting cables.11.0 GUARANTEE ASL 19” rack mount units are housed in a 1 mm steel enclosure (closed construction), which offers, by nature, the highest possible rejection of electro- ASL Intercom warrants this unit to the original end-user magnetic fields purchaser against defects in workmanship and materials in its manufacture for a period of one year from the date ASL speaker stations (PS 130/230/430) are housed in of shipment to the end-user. an enclosure made of 1 mm steel with ABS side panels, which offers adequate rejection of electro- Faults arising from misuse, unauthorised modifications magnetic fields. or accidents are not covered by this warranty. If the unit is faulty, it should be sent in its original packing to the ASL beltpacks are housed in an ABS enclosure and supplier or your local ASL dealer, with shipping prepaid. are slightly more sensitive to electro-magnetic fields. A note must be included stating the faults found and a Negative effects in the performance of beltpacks can copy of the original suppliers invoice. be avoided when keeping them at a safe distance from equipment which might radiate strong electro-magnetic fields, such as transmitters antennas and dimmers. THIS PRODUCT WAS DESIGNED, DEVELOPED AND MANUFACTURED BY: ASL INTERCOM BV UTRECHT, THE NETHERLANDS Website: Email: info@asl-inter.comUser manual PS 279 / Issue 1 © 2006 ASL Intercom, Utrecht, The Netherlands 11
  12. 12. 13.0 TECHNICAL SPECIFICATIONS PS 279 POWER SUPPLY mains voltage range All units : 100 – 240 V 50/60Hz AC DC ouput voltage +30 V +/- 5% DC ripple and noise < 11 mV rms max. output current 2.5 A continous, 3.5 A peak circuit breaker delay time 0.2 sec. automatic reset time 3.0 sec. DC Input 12 – 28 V AUX INPUT input impedance 11 Kohms Nominal input level -20 dBu to +10 dBu Max. input level +21 dBu MIC. PREAMP mic. impedance 200 ohms gain 40 dB - 60 dB (adjustable internally) presence filter +6 dB at 5 kHz frequency response 200 Hz – 15 kHz (-3 dB) V electret mic. + 9 V DC HEADPHONES DRIVER AMP max. load 100 ohms max. output level normal 16 V rms (200 ohms) binaural 2 x 8.5 V rms (400 ohms) max. output power normal 0.5 W rms (each can) binaural 2 x 0.2 W rms (each can) SIDETONE rejection 0 – 30 dB adjustable BUZZER max. SPL 100 dBA DIMENSIONS AND WEIGHT width 19" (483 mm) height 1U (44.5 mm) depth 150 mm weight 1.85 Kg GENERAL SYSTEM SPECIFICATIONS intercom line impedance 350 ohms (1kHz) 2.2 Kohms (DC) intercom line audio level nom. –18 dBu Max. +4 dBu dynamic range 80 dB call send signal +2.8 mA call receive signal threshold +2.4 V DC supply voltage +30 V DC (12 V to 32 V) mic mute power interrupt time 0.1 sec. Note: 0 dBu = 775 mV into open circuit. ASL reserve the right to alter specifications without further notice. 12 User manual PS 279 / Issue 1 © 2006 ASL Intercom, Utrecht, The Netherlands
  13. 13. User manual PS 279 / Issue 1 © 2006 ASL Intercom, Utrecht, The Netherlands 13
  14. 14. 14 User manual PS 279 / Issue 1 © 2006 ASL Intercom, Utrecht, The Netherlands
  15. 15. User manual PS 279 / Issue 1 © 2006 ASL Intercom, Utrecht, The Netherlands 15