Comtech EF Data CDM-750 - Manual (Page 94)

CDM-750 Advanced High-Speed Trunking Modem Revision 2
Front Panel Operation MN-CDM750
5–16
Item Description
TxPLL
(Alarm) The Tx Clock PLL is railed high or low indicating that the Tx Clock Source is
substantially different than the rate of the Tx data.
InpSigLoss
(Alarm) Input Signal Loss indicates that no traffic is being seen by the OC3/STM-1 interface
on the TX-IN connector.
RxPLL
(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.
RxOF
(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.
RxUF
(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.
Using TxPLL as the example:
Tx Pll Mask: Masked
Alarm Fault Mask Fault-Tx On
The top line notes the active mask selection. On the bottom line, use the W X arrow keys to
select Alarm, Fault, Mask, or Fault‐Tx On for the TxPll and InpSigLoss menus, or Alarm, Fault, or
Mask for the RxPll, RxOF and RxUF menus. Press ENTER when done. Note the following:
Mask Type Description Redundancy Switchover and Tx Mute
Alarm Alarms can be viewed from the Monitor: Live
Alarms menu (Sect.5.2.4.1). Alarms cause the
Unit Status LED to turn AMBER.
An alarm WILL NOT cause a redundancy
switch and WILL NOT mute the Tx carrier
Fault 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
A fault WILL cause a redundancy switch
and WILL mute the Tx carrier
Mask Masking the event has the effect of ignoring the
event – it can no longer be logged and is not
seen in any menu.
Mask WILL NOT cause a redundancy
switch and WILL NOT mute the Tx carrier
Fault-Tx On 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
A Fault-Tx On WILL cause a redundancy
switch and WILL NOT mute the Tx carrier