Codan NGT 2010 RF Technical & Service Manual page 668

NRI—Fault finding
Table 7: Description of LEDs (cont.)
State of LED
Fast alternating
red/green
Slow alternating
red/yellow
274
Description
The lists stored on the device are being viewed on the handset.
When viewing is complete, the LED switches off for a period of
time before resuming the state it was before it displayed red/green.
The firmware download has been successful and the device is
verifying the status of other devices in the network.
The LED indicates the progress of a firmware download. It
alternates colours on successive data packets received and at a rate
dependent on packet size and type of interface.
NGT Transceiver System Technical Service Manual