User manual

Appendix C. System Messages
C-2 TDU 120e User Manual 61202156L1-1
Table C-1. Network Interface (NI) Alarms
Alarm Name Description
Red Alarm NI unable to frame align with incoming signal
Yellow Alarm Remote alarm indication (RAI) being received
from far end
Blue Alarm Unframed all ones (1s) (AIS) being received at NI
Loss of Signal No signal detected at NI
Table C-2. Nx/DBU Interface Alarms
Alarm Name Description
Clock Slip Difference in frequency of the data clock at the net-
work and DTE
PLL Alarm Unable to achieve Phase Locked Loop on the clock
provided by the network interface.
Zeros Alarm All zeros (0s) data being sent toward the network
interface
FIFO Alarm Error in propagation of data through the FIFOs
No EXT Clock No external transmit clock at DTE (only appears if
EXT CLK is selected)