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Issue 3
3.
Limiter
Selecting the limiter will ensure that the signal level remains fairly constant irrespective of input level changes.
Using it will prevent system overload when different personnel use the microphone or speak too close to the
microphone.
Technical Specification
MICROPHONE
LINE
Nominal output level
2.5mV
250mV
Maximum output level limiter operating
7mV
700mV
Output impedance
47ohms
400ohms
Frequency Response
200Hz - 10KHz
Power Requirements
24V DC
26mA Standby
100mA Max
The cable is terminated to a 25 way ‘D’ connector. It is supplied with a BMS25 single gang socket box and
connections are made using screw terminals
FUNCTION
CABLE COLOUR
BMS 25 CONNECTIONS
ZONE 1
NPN open collector outputs 40V @
Green
1
2
100mA Max. to zone select relays
Grey
2
3
etc. Connects to 0V when the zone
Pink
3
4
and speak keys are selected together.
Orange
4
AUDIO - Output floating
Brown
16
CABLE SCREEN - Connect to 0V
17
AUDIO - Output floating
Blue
18
0V
Black
19
24V DC - Supply input
Red
20
ACCESS - Amplifier -
White
21
connects to 0V when speak or All Call keys are pressed. 24V @ 30mA
BUSY Indicator - Switch to 0V to illuminate
Mauve
22
1. Remove 2 screws
2. Lift top
at rear
3. Slide top forward
and off base
98
m
m
65mm
4mm fixings
FIG 2a - BDM 204 - Wall Mounting Dimensions
FIG 2b - BDM 204 - To remove the base