TERMINAL

The Modem takes control of the BUC to act as an integrated terminal, and the two

 

together respond as follows:

 

The modem IF output level screens are replaced by a screen allowing the

 

operator to set the output power at the BUC flange.

 

The Modem continuously reads the monitored power output from the BUC,

 

and automatically varies the modem IF level and BUC attenuator to maintain

 

the set power at the BUC flange (ie compensates for temperature changes

 

in cable, equipment etc).

The BUC Tx On/Off output is maintained as `On` (the Tx carrier can still be

muted on Change, Tx, Modulator, Carrier menu).

The modem automatically reads the frequency shift from the BUC, and configures the modem for display / entry of the final SHF frequencies instead of IF frequencies.

Terminal mode can only be used with a single carrier through the BUC, as the modem will try and compensate for the combined measured power by adjusting the single carrier from the modem controlling the BUC.

Terminal mode, where the Tx power is varied to maintain a steady level at the BUC flange, is NOT compatible with AUPC which requires the Tx power to vary to meet receive criteria.

6.12.3Change, BUC/LNB, Tx/BUC, DC & REFERENCES Menu

This screen is only available on P310 L-Band modems where the BUC Type has been set to other than

None

 

 

 

 

Tx/BUC: 1:DC Supply[On] 2:10M Ref[Off]

 

 

3:Current Monitor[2400 - 2800mA]

 

 

 

 

 

 

 

 

Change, BUC/LNB, Tx/BUC, DC & References Menu

DC SUPPLY

If fitted with the P315 BUC DC supply option, then the modem may source 100W

 

of 24V or 48V (factory option) to the BUC `up the coax` or `line powered`. The

 

only option available here is On or Off.

 

CAUTION: Needless to say severe damage may occur if a DC supply is fed to a

 

BUC not configured for being `Line powered`.

10M REF

The internal 10MHz reference may similarly be sourced from the modem `up the

 

coax` to the BUC. The only option available here again is On or Off.

CURRENT

 

 

MONITOR

If the modem is sourcing the DC supply to the BUC, then it may be set to monitor

 

the current drawn by the BUC, and to raise an alarm (Tx Fault) if it goes outside

 

a user defined window. Two subsequent screens allow the user to independently

 

set the low and high current alarm thresholds. The current being drawn by the

 

BUC can be monitored from the Monitor, BUC menu’s

P300H

P300 Series Modem Installation and Operating Handbook

Page 110

Page 110
Image 110
Paradise P300 Change, BUC/LNB, Tx/BUC, DC & References Menu, Tx/BUC 1DC SupplyOn 210M RefOff 3Current Monitor2400 2800mA