4RF Aprisa XE User Manual page 123

3. Set the DFXO Input Level and the Output Level required:
Signal Direction
Input Level (L )
i
Output Level (L )
o
In the example shown below, the PSTN exchange line card is connected to a DFXO card.
The levels are set based on the system using a 0 dBr transmission reference point.
DFXO Input Level setting
The exchange line card has a nominal output level of -6 dBr. To achieve a digital reference point
transmit level of -2.0 dBm0, the DFXO input level is set to -4.0 dBr (effective T pad gain of 4.0 dB).
The deliberate 2 dB of loss between the exchange line card and the DFXO provides a 2 dB of overall
circuit loss between the DFXO and the DFXS.
DFXO Output Level setting
The exchange line card has a nominal input level of +1.0 dBr. With a transmission reference point
received level of -2.0 dBm0, the DFXO output level is set to -1.0 dBr (effective R pad loss of 1.0 dB).
The deliberate 2 dB of loss between the exchange line card and the DFXO provides a 2 dB of overall
circuit loss between the DFXS and the DFXO.
4. Click Apply to apply changes or Reset to restore the previous configuration.
Level adjustment range
-10.0 dBr to +1.0 dBr in 0.5 dB steps
-10.0 dBr to +1.0 dBr in 0.5 dB steps
Aprisa XE User Manual
Configuring the Traffic Interfaces | 121
Default setting
-4.0 dBr
-1.0 dBr