LEDs

Color

Indication when On

Ready

Green

The module has passed powerup diagnostics.

Run

Green

Indicates that the unit is in kernel mode – should always be OFF during normal operations. Note: The table for the NOM 21X 00 shows the number of times the RUN LED on the Modbus Plus on Fiber Module blinks for each type of error and the crash codes for each (all codes are in hex).

Modbus

Green

Indicates communication is active on the single RS-232 serial port.

Modbus+

Green

Indicates communication is active on the Modbus Plus port.

Fport1

Green

Indicates an optical signal has been received on fiber optic Port 1.

Fport2

Green

Indicates an optical signal has been received on fiber optic Port 2.

FRNGoff

Red

Indicates the first break in a self healing ring.