Philips SM30 manual Electret condenser microphone, Built-in Compressor, Balanced Line Level output

6	CALL STATION
	(CST)	LBB 9568

The SM30 Call Station presents the operator with a logical, comprehensive, and easy to use method of routing and broadcasting calls, announcements, and music. Since each Call Station Input Module will accept two Call Stations, SM30 will accept up to 6 Call Stations in total.

Electret condenser microphone

The high quality phantom powered microphone with built-in bass rolloff filter (fig.6.1L) gives clear voice reproduction, even in difficult acoustic environments.

Built-in Compressor

Helps to keep the audio output level of the Call Station constant, even in situations where the operator’s speech volume level changes radically. The amount of compres- sion is dependent on the Microphone pre- amplifier gain setting: the higher the gain setting, the greater the amount of compres- sion, and therefore the greater the effect on the microphone signal (see paragraph 6.3).

Balanced Line Level output

Allows Call Stations to be located up to 1000 metres from the Control Centre.

6.1Operating controls

Numeric Keypad (fig.6.1J)

Allowing individual selection of up to 18 loudspeaker zones by typing in the zone number. Each Call Station can be programmed with a priority status, attention tone and pre-recorded message. These become operational whenever the keypad is used to route a call. (See chapter 14 for programming details).

Redial function (fig.6.1I)

Repeats the last zone selection.

Zone Selection Indicator (fig.6.1B) Each zone has its own LED which is illuminated when the zone is selected. When the call is completed the LEDs will be extinguished.

Function Keys (fig.6.1K)

The 4 function keys are to be programmed with priority; alarm and attention tones; pre-recorded messages; routing to loudspeak- er zones; and Control Relay activation. The alternative functions of these keys include: music volume up/down; music source selection; music mute; and independent Control Relay switching or toggling (see chapter 14 for programming details). Using the Function Keys to make a call is done in the same way as using the Keypad. The main difference being that instead of the operator selecting the zones using the Numeric Keypad, the Function Keys route the call to a pre-programmed selection of zones. This of course saves a great amount of time when an operator has to frequently call the same selection of zones, or when an “ALL CALL” must be made in emergencies. Each Function Key may be programmed to carry out a totally different task.

Key F1 can be programmed to route a low priority call, preceded by an attention tone, to several, frequently used, loudspeaker zones.

Key F2 could be programmed to route an alarm tone, followed by a pre-recorded evacuation message, to all loudspeaker zones (an “ALL CALL”).

Key F3 could be used to mute the music signal.

Key F4 could be used to toggle a Control Relay on and off, switching a warning lamp, illuminated notice, etc..

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