User's Manual Part 3

Screen Service SDT 501 UB-C ARK 1-T Operations
May, 2010 v 1.0 Page 3 - 96
Alarm Description and limitations Troubleshooting
communication error) is raised.
• If the frequency reference is Internal: internal PLL fault
• If the frequency reference is External:
o Internal PLL fault
o Lack of external 10 MHz
o Hardware fault
• If the frequency reference is GPS:
o Internal PLL fault
o 10 MHz line from the GPS receiver hardware fault
Signal 120 MHz Lock
120 MHz is not locked.
Alarm raising limitations:
The monitoring of this alarm is disabled when the signal 10
MHz lock alarm is raised or when GPS is used as clock
reference and a GPS alarm (GPS lock, GPS communication
error) is raised.
• In SFN configuration, when selected TS input or MIP are not
detected, 120 MHz oscillator can lose the lock
• Hardware fault