Comtech EF Data CDM-760 Installation And Operation Manual page 124

Front Panel Operation
CDM-760 Advanced High-Speed Trunking Modem
Selection (Alarm)
ExtClkInRange
RxPLL
RxOF
RxUF
Use the  arrow keys to set the report state for each selection as Alarm, Fault,
Mask, or Fault-Tx On. (The RxPll, RxOF, and RxUF selections provide only Alarm, Fault,
and Mask.) Press ENTER. Note the following:
Mask State
Alarm
Fault
Mask
Fault-Tx On
(CONFIG: INTF) (PIICX=G703)  BufSize (Rx Buffer Size)
Rx Buffer Size: 02.0 ms
Use the  arrow keys to change the Rx Buffer Size time value. Press ENTER. Valid settings are:
Minimum
2 ms
(CONFIG: INTF) (PIICX=G703)  Center (Rx Buffer Re-Center)
PIICX: Type:E3 ClkSource Mask
BufSize:32.0ms
The Fill Status is a read-only status of buffer depth, reported as a percentage:
Description
External Clock In Range means that the External Clock is set by the TxClock or
RxClock, but the rate of the clock on J8 | EXT REF does not agree with the rate
expected by the modem.
The Rx Clock PLL is railed high or low, meaning that the Rx Clock Source is
significantly different than the rate of incoming data.
Rx Overflow means that the demodulator traffic is too fast for the RxClock clock
setting. This causes the buffer to overflow and to re-center, losing data in the
process.
Rx Underflow means that the demodulator traffic is too slow for the clock RxClock
setting. This causes the buffer to underflow and to re-center, losing data in the
process.
If ExtClkAct IS NOT in an Alarm or Fault condition but the ExtClkInRange IS in
Alarm or Fault condition, this means that the clock source rate and the
modem's programmed External Clock rate are different.
Front Panel LED
'UNIT STATUS' Fault State
Color
Amber None
J1 Alarm
Red
Connector
None None
J1 Alarm
Red
Connector
Range
Maximum
75 ms
Center:No
Causes
Mutes
Redundancy
Tx Carrier
Switch
No
Yes
No
Yes
Step Size
0.5 ms
Fill=50%
6–35
Revision 4
MN-CDM760
Front Panel VFD
Visible Location
No Monitor: Live Alarms menu
Yes Monitor: Stored-Events Log
None: A masked event is not
logged and is not seen in
No
any menu.
No Monitor: Stored-Events Log
()
()