User manual ASL INTERCOM PS 279

[. . . ] PRO SERIES USER MANUAL FOR THE PS 279 DUAL CHANNEL MASTER STATION CONTENTS 1. 0 2. 0 3. 0 4. 0 5. 0 6. 0 7. 0 8. 0 9. 0 10. 0 11. 0 12. 0 13. 0 SAFETY INSTRUCTIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 GENERAL DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 UNPACKING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 MAINS POWER. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 CABLING. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [. . . ] POWER LED This LED illuminates if line power is supplied by the internal power supply. SYSTEM LINK IN A This LED illuminates if another ASL Intercom System has been connected to the PS 279 through the "System Link" connector of Channel A. The Line Impedance is now provided by the other Intercom system and the internal line impedance for Channel A is switched off. The Buzzer mute function on Channel A can now only be controlled by the connected system, while the Buzzer Mute on Channel B 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 A 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. 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. Adjusting the sidetone does not affect the level of your voice as it is heard by other stations. TALK buttons These buttons allow you to talk to each channel separately or simultaneously. Latched switching: When a TALK button is pressed shortly, the microphone of the chosen channel will be switched on and latches electronically. 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. 13 15 CALL A & B buttons These push buttons activate the CALL system. A momentary push will send a visual CALL signal to all stations connected to that intercom channel and the CALL LEDS will start flashing. When holding the buttons pressed for 2 seconds, the buzzer will be activated. After the CALL button is released the LEDS will continue to flash for further 2 seconds. 16 HEADSET connector A XLR-4 type connector to connect the local headset. The headset-can must have an impedance of 200 ohms or greater, or each 400 ohms minimum when in parallel. phones ­ The wiring is such that both headset cans are connected in parallel and receive the same signal. As an option, an XLR-6 type connector can be fitted to allow a binaural headset configuration where a different signal will appear on each can. See section 7. 1 Internal Jumpers and Controls. 14 User manual PS 279 / Issue 1 © 2006 ASL Intercom, Utrecht, The Netherlands 7 7. 0 REAR PANEL CONTROLS AND CONNECTOR 17 A & B LINE connectors These XLR-3 type connectors are for connecting the remote-stations, via standard microphone cable. There are two connectors for channel A and two connectors for channel B. [. . . ] Each station utilises a current amplifier to amplify the microphone signal and place it on the common audio line where, due to the constant line impedance (situated in the power supply between XLR pin 3 and 1), a signal voltage is developed which can be further amplified and sent to headphones or loudspeakers. This principle has three advantages: the use of a single audio line allows several stations to talk and listen simultaneously. due to the high bridging impedance offered by each station, the number of stations 'on line' has no influence on the level of the communications signal. power and audio to the intercom stations use the same cable. 12. 0 DESIGN CRITERIA Applications / Environment of use ASL Pro Series equipment is designed for use as a wired communications system in theatres, in Radio/TV production facilities, in factories, and in utilities complexes such as airports, railway stations and coach terminals. [. . . ]