During the link implementation of the RTN 950 XPIC link 1+0, QPSK, 7Mbps, 17GHz, achieving a XPD correct value was difficult in case of technical skills or hardware issues. Therefore, is not always easy to identify when the real problem of not achieving the XPD correct value comes because of the installation skills or a hardware defect. RTN 950 uses 5.83.03.31 version and IFX2 boards.
No alarms related.
One recommended process to reach the calculated XPD value is:
By loosening up the screws that hold feed horns, minor adjustments vary the RSSI and RSL values. Theoretically, the difference in RSL between vertical and horizontal polarization is called ‘Cross Polarization Discrimination’ (XPD).
XPD value is usually determined by antenna specification. Some high XPD antenna has the XPD value up to 40 or 30 dB. If the required XPD value cannot be achieved, the received signal from opposite polarization will cause interference. Common symptoms are wrong received link ID and generation of MW-LOF alarm.
Every time you loose up the screws that hold feed horns, verify the current performance values in both ends, in both IFX2 slots by WebLCT or command line you can use:
bid represents the IFX2 board slot, where XPD_CUR is the current XPD value to be set accordingly.