Comtech EF Data CDM-750 Installation And Operation Manual page 88

CDM-750 Advanced High-Speed Trunking Modem
Front Panel Operation
(CONFIG: INTF) PIICX (G.703)
Rx Buffer: BufferSize
Use the arrow keys to select BufferSize or ReCenter, and then press ENTER.
The bottom line displays the present RxBuffer Fill Status as a percentage. If the RxBuffer Fill Status
is dropping (approaching 0%), this indicates that the Rx traffic is not keeping up with the Rx Clock
setting and a data underflow is occurring. If the RxBuffer Fill Status is increasing (approaching
100%) the Rx traffic is coming in faster than the Rx Clock setting accommodates, and a data
overflow is occurring.
(CONFIG: INTF) PIICX (G.703)
Rx Buffer Size: 02.0 ms
Use the arrow keys to increment/decrement the Rx Buffer Size time value (from 2 ms to 75
ms in 0.5 ms steps), and then press ENTER.
(CONFIG: INTF) PIICX (G.703)
Rx Buffer: ReCenter
In the event of data underflow or overflow (as indicated by the Fill Status percentage reported
on the RxBuffer menu) press ENTER to ReCenter the Rx Buffer depth to 50%.
(CONFIG: INTF) PIICX (G.703)
Masks: TxPll
To define how many or how few of the interface alarm or fault states are reported: Use the
arrow keys to select TxPll, InpSigLoss, ExtClkAct, RxPll, RxOF, RxUF, or ExtClkInRange, and then
press ENTER. Note the following:
Item
TxPLL
InpSigLoss
ExtClkAct
RxBuffer
Fill Status = 00%
RxBuffer
RxBuffer
Mask
InpSigLoss ExtClkAct
RxPll RxOF
Description
(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.
(Alarm) Input Signal Loss indicates that no traffic is being seen by the G.703 interface on
the TX-IN connector.
(Alarm) External Clock Activity indicates that the External Clock is selected by either the
TxClock or RxClock but no clock is present on J8.
ReCenter
(
BufferSize
(
Recenter
(
RxUF ExtClkInRange
5–12
Revision 2
MN-CDM750
)
)
)