3Com NBX 100 Installation Manual page 41

Status Lights — These lights indicate the status of the card's
signaling, synchronization, and loop back test.
CO — Central Office:
Amber — Alarm condition at the remote end or the CO is not
connected or available.
Green — No alarm condition.
POST — Power On Self Test:
Off — POST test is running. The test runs approximately 5 seconds
after you apply power to the board. After 5 seconds, Off indicates
that the POST test failed.
Green — POST test completed successfully.
DCH — D channel status of an ISDN PRI connection
Off — No E1 or E1 PRI line is attached.
Green — Card is configured for ISDN PRI operation and an active
PRI connection has been established.
Amber — The D channel has not yet been established. It can take
several seconds after the card has completed its power up tests for
the card to establish a connection with the PRI trunk. If the DCH
light goes to amber after the connection has been established, it
can mean that an active control channel connection through the
PRI line has been lost.
DNLD — Download
Flash — The card is downloading software from the NCP.
Green — The download is complete or the Power-On-Self-Test
(POST) is running.
Amber — The download was interrupted before it was completed.
On a LAN, the download process is completed quickly. If the
download from NCP to digital line card must travel a routed
network path, the download may take a few minutes. If the DNLD
light remains amber, it can indicate a severely congested network
or a hardware problem with the card.
CALL — Call audio traffic
Off — No audio traffic on the T1 link.
Flashing — Audio traffic is present.
CARD — Card Software Status
NBX Cards and Devices 41