GE Security EST3 Installation And Service Manual page 260

Service and troubleshooting
8.10
network communication between CPU modules in other cabinets
is also processed by the CPU. Network communication is
RS-485 when the 3-RS485 card is installed in CPU connector J2,
and fiber optic when the 3-FIBMB or 3-NSHM module is
connected to J2 of the CPU.
Network and audio data circuits
Figure 8-1 and Table 8-4 show the location and normal state of
the communication status LEDs on the CPU module.
N C N
C O
TROUBLE
J1
NETWORK AUDIO AUDIO AUDIO AUDIO
R
OUT B IN
IN A IN A OUT B OUT
A A B B
X
+ - + - + - + - + - + - 1
[CPULEDS.CDR]
Figure 8-1: CPU module
Table 8-4: CPU LED indications
LED Normal Description
state
RX1 Flicker Local Rail Receive Activity
TX1 Flicker Local Rail Transmit Activity
RX2 Flicker Network Data Ch A Receive Activity
TX2 Flicker Network Data Ch A Transmit Activity
N C N N N C N
-
O C O C
A
ALARM SUP
TB1
Rx1
Tx1
Rx2
Tx2
Rx3
Tx3
R C R C
T T O R T T O
X M X M
S X S
1 1 1 2 2 2 2
EST3 Installation and Service Manual