Comtech EF Data CDM-750 Installation And Operation Manual page 89

CDM-750 Advanced High-Speed Trunking Modem
Front Panel Operation
Item
RxPLL
RxOF
RxUF
ExtClkInRange
Using the TxPLL menu as the example:
Tx Pll Mask:Fault
The top line notes the active mask selection. On the bottom line, use the arrow keys to
select Alarm, Fault, Mask, or Fault‐Tx On, and then press ENTER. (For the RxPll, RxOF and RxUF,
menus, only Alarm, Fault, and Mask are provided.) Note the following:
Mask Type
Alarm
Fault
Mask
Fault-Tx On
Description
(Alarm) The Rx Clock PLL is railed high or low indicating that the Rx Clock Source is
substantially different than the rate of incoming data.
(Alarm) Rx Overflow indicates that the traffic received by the demod is exceeding the clock
RxClock setting and is therefore overflowing the buffer causing the buffer to re-center and
take a data hit.
(Alarm) Rx Underflow indicates that the traffic received by the demod is not keeping up with
the clock RxClock setting and is therefore underflowing the buffer causing the buffer to re-
center and take a data hit.
External Clock In Range indicates that the External Clock is selected by either the TxClock
or RxClock but the clock rate on J8 does not meet the expected rate by the modem. Note:
When ExtClkAct IS NOT in an Alarm or Fault condition but the ExtClkInRange IS in Alarm or
Fault condition, it is an indication that the clock source rate and the modem's programmed
External Clock rate are different.
Alarm Fault Mask
Description
Alarms can be viewed from the Monitor:
Live Alarms menu (Sect.5.2.4.1). Alarms
cause the Unit Status LED to turn AMBER.
Faults can be viewed in the Monitor:
Stored-Events log (Sect. 5.2.4.2).
Faults cause:
• The Unit Status LED to turn RED
• The J1 Alarm Connector to show a
Fault
Masking the event has the effect of ignoring
the event – it can no longer be logged and
is not seen in any menu.
Faults can be viewed in the Monitor:
Stored-Events log (Sect. 5.2.4.2).
Faults cause:
• The Unit Status LED to turn RED
• The J1 Alarm Connector to show a
Fault
Fault-Tx On
Redundancy Switchover and Tx Mute
An alarm WILL NOT cause a redundancy switch
and WILL NOT mute the Tx carrier
A fault WILL cause a redundancy switch and
WILL mute the Tx carrier
Mask WILL NOT cause a redundancy switch
and WILL NOT mute the Tx carrier
A Fault-Tx On WILL cause a redundancy switch
and WILL NOT mute the Tx carrier
5–13
Revision 2
MN-CDM750