BDM 400 Microphones
Operating Instructions
8
BDM400 Operation Manual issue 10
2.4 P
ROCESSOR
B
YPASS
“A
LL
C
ALL
”
OPTION
It is possible to add an extra hard wired “All Call” processor
bypass access switch to the BDM microphones to enable
broadcasts in the unlikely event that the router suffers from a
processor fault or RS485 network failure.
The bypass switch should be connected between JP8 & JP9, a
solder bridge should be made across LK3, and LK4 should be
carefully drilled out as shown in Figure 2.4.
Figure 2.4 — Connections required for Processor Bypass “All Call” switch
N
OTE
: This is a modification that is normally a factory fitted option.
N
OTE
: The BDM401 in Parallel mode can access an "All Call" bypass
input without adding an extra switch.
N
OTE
: The BDM microphone must be connected to the correct input on
the BVRD2M for the processor bypass to operate.
N
OTE
: If the Access line is to be monitored ensure JP4 is set to "MON".
For further information refer to Figure 2.2.
