Philips SM30 plug-in modules, Call Station, Signal generator, Background music, Block diagram

SM30 plug-in modules

All of the interconnections between individual modules in the Control Centre take place automatically when they are plugged into the interconnection board of the Control Centre, so that no complex inter-wiring is required. Owing to the unique construction of the housing, the modules slide in and out quickly and easily. These features make SM30 simple and inexpensive to install and maintain.

All switching and routing of the system is carried out by software, so that hard-wiring problems are kept to a minimum. This means that though SM30 comprises a great amount of features, making it a comprehensive Public Address Centre, the unit itself is uncluttered and simple to assemble and use.

Call Station

The Call Station is the primary input to the system, allowing the operator to route and broadcast calls, announcements and music. Each Call Station includes:

■An electret condenser microphone.

■A Numeric Keypad, 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.

■Zone Selection Indicator.

Each zone has its own LED which is illuminated when the zone is selected. When the call is completed the LEDs will be extinguished.

■4 Function Keys.

Programmable with: priority; alarm and attention tones; pre-recorded messages; routing to loudspeaker zones; and Control Relay activation.

■Alternative functions.

These include music volume up/down; music source selection; music mute; and independent Control Relay switching or toggling.

Using the Function Keys to make a call is done in the same way as using the Key-pad. 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.

Signal generator

Built into the SM30 Control Centre is a signal generator, programmed with attention tones and alarm signals. These can be programmed, via the User Menu, to precede a call or pre-recorded message, or to be activated independently.

Background music

Background music sources, such as a background music player, a radio tuner, a compact disc player, a cassette deck, etc. are connected and pre-adjusted.

Emergency Power Supply +48 VDC

In situations where the mains power supply is unreliable, and SM30 is used for security/evacuation purposes, an emergency power supply may be used. This will be switched on automatically whenever the mains power fails.

Block diagram

The block diagram of a SM30 system is shown in fig.1.

2