GFK-1504N
Chapter 6 Expansion Modules
6-9
6
LED Indicators
Three LEDs display the status of module power, the expansion port, and the I/O
modules.
The PWR LED is ON when the module is receiving 5 V DC power from the
attached power supply. It is OFF when there is no power supply attached or
when the power supply itself is not receiving power.
The SCAN LED lights green when the CPU/NIU is actively scanning I/O in
expansion racks. It lights amber when the CPU/NIU is not actively scanning I/O
in expansion racks.
The EXP RX LED indicates the status of the expansion bus. This LED is either
blinking or ON when the Expansion Receiver is communicating with the
Expansion Transmitter. It is OFF when not communicating.
Expansion Rack Selection Switch
The Rack Selection Switch specifies which expansion rack the ERM is in.