Specifications

Bosch Security Systems | 2007-08 | 9922 141 50672en
Plena Loop Amplifier | Installation and User Instructions | System overview en | 12
1.7 Controls, connectors and
indicators
1.7.1 Front view
The front of the loop amplifier (refer to figure 1.3)
contains:
1 Power LED/VU Meter - A combined power LED
and VU meter. The green power LED comes on
when the loop amplifier is switched on. The VU
meter shows the master VU level: 0 dB (red), -6 dB,
-20 dB (yellow).
2 Electric current meter - Show the electric
current through the induction loop.
3 Fault LED - Comes on when a supervised function
of the loop amplifier fails (refer to section 6.5).
4 Headphones socket - Connects headphones to
the loop amplifier.
5 Limiter LED - Comes on when the limiter is active
(refer to section 6.5).
6 AGC LED - Comes on when the automatic gain
control (AGC) is active (refer to section 6.5).
7 Loop integrity LED - Comes on when the
induction loop is intact (refer to section 6.5).
8 Master volume control - Sets the maximum
electric current that flows through the induction loop
(refer to section 5.2).
9 Tone controls - Controls the high and low tones of
the audio signal on the induction loop (refer to
section 6.4).
10 Input volume controls - Control the volume of
audio input 1 and audio input 2 (refer to section 6.3).
11 On/off switch - Switches the loop amplifier on and
off (refer to section 6.1 and section 6.2).
1.7.2 Rear view
The rear of the loop amplifier (refer to figure 1.3)
contains:
12 Metal loss compensation control - Controls the
metal loss compensation (refer to section 5.3).
13 Master/slave sockets - Connect master and slaves
to the loop amplifier (refer to section 4.7).
14 Line output - Connects an external recording
device to the loop amplifier (refer to section 4.5).
15 Fault output - Sends the condition of the loop
amplifier to other equipment (refer to section 4.4).
16 Supervision switch - Switches supervision of the
priority input on and off (refer to section 5.4).
17 Voltage selector - Selects the voltage on which the
loop amplifier must operate (refer to section 4.6).
18 Power inlet - Connects the loop amplifier to the
mains power supply with a power cable (refer to
section 4.6).
19 Ground screw - Connects the loop amplifier to
ground.
20 Induction loop output - Connects the induction
loop to the loop amplifier (refer to section 4.1).
21 Audio inputs - Connects the loop amplifier to
external audio inputs (refer to section 4.2).
22 Priority input - Connect the loop amplifier to
systems that can override the audio signal on the
induction loop (refer to section 4.3). For example, a
Plena Voice Alarm System or a Praesideo system.
23 Frequency range switch - Select the frequency
range of the audio signal on the induction loop (refer
to section 5.8).
24 AGC/Limiter switch - Selects the automatic gain
control (AGC) or the limiter (refer to section 5.7.2).
25 AGC range control - Controls the range of the
automatic gain control (see section 5.7.3).