98-16081b
System
LEDs
NET
DSU/CSU
3166
Port1
OK
Fail
Test
Sig
OOF
Alrm
EER
DTR
TXD
RXD
CTS
RTS
Select
In
Out
Net
Mon
SDCP Operation
3-4 3166-A2-GB20-10
November 1998
LEDs

There are twelve LEDs on the 3166 DSU/CSU front panel.

A green LED indicates normal operation. A yellow LED indicates activity.

Conditions are sampled every tenth of a second.

The twelve front panel LEDs are grouped into three sections to indicate the status

of the:

System (Table 3-1)

Network Interface (Table 3-2)

Data Port (Table 3-3)

Table 3-1. System LEDs

Name Color Meaning
OK
(Select) Green Indicates the current operational state of the DSU/CSU.
ON:
The DSU/CSU is operational and has power.
OFF:
The DSU/CSU is performing a power-up self-test or a
system failure has occurred.
BLINKING:
A software download is in progress.
FAST BLINK:
The DSU/CSU is currently selected by the SDCP.
Fail Yellow Indicates a system failure or a self-test.
ON:
A device error/fault is detected or a reset has just
occurred.
OFF:
No system failures are detected.
BLINKING
: A self-test is in progress.
Test Yellow A system test is in progress.
ON:
A loopback or pattern test has been initiated either
locally, by the network, or externally.
OFF:
No tests are active.