Chapter 3. O peration
61200420L1-1 ESU 120e User Manual
3-3
LED D escriptions
CSU Status
The CSU status LEDs display the operational condition of the network
interface located on the controller board in the unit.
DSU/Drop Status
Name Description
OK
(green) Indicates the operation is in the normal mode and no
errors have been detected.
Te s t
(yellow) Indicates that the network interface is operating in a test
mode. This includes a self-test or a test loopback.
When lighted, this LED also indicates that normal data
flow is not occurring on the network interface.
Error
(red) Indicates an error such as a BPV, OOF, or CRC.
Alarm
(red) Indicates an alarm condition has been detected. When
the alarm condition is no longer valid, the OK LED
activates (turns on). To view an alarm condition, select
the active alarm menu item or select Alarm by pressing
Shift 8
. If the alarm conditions have been corrected, the
alarm which caused the activation of the Alarm LED
can be viewed under the Unit History menu.
Name Description
OK
(green) Indicates the operation is in the normal mode and no
errors have been detected.
Te s t
(yellow) Indicates that the interface is operating in a test mode.
This includes a self-test or a test loopback. When
lighted, this LED also indicates that normal data flow is
not occurring in at least one of the module ports.
Alarm
(red) Indicates an alarm condition has been detected. When
the alarm condition is no longer valid, the OK LED
activates (turns on). To view an alarm condition, select
the active alarm menu item or select Alarm by pressing
Shift 8
. If the alarm conditions have been corrected, the
alarm which caused the activation of the Alarm LED
can be viewed under the Unit History menu.
