Cambium Networks PTP 820 Series, User Manual

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Chapter 15: Configuration Guide (CLI) Configuring XPIC (CLI)
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5. The XPI should be between 25dB and 30dB. If it is not, you should adjust the OMT assembly on the back of the
antenna at one side of the link until you achieve the highest XPI, which should be no less than 25dB. Adjust
the OMT very slowly in a right-left direction. OMT adjustment requires very fine movements and it may take
several minutes to achieve the best possible XPI.
Note
As an extra step, to check the veracity of the initial measurements, you can mute the first carrier and
unmute the second carrier on the upper carriers on both sides of the link. Then measure the RSL of
the second carrier link (the “RSL
wanted
”), measure the RSL of the first carrier (the “RSL
unwanted
”) and
determine the XPI. The XPI should match the XPI with the second carriers muted.
6. Unmute all the carriers and check the RSL levels of all the carriers on both sides of the link. The RSL of the
horizontal carrier of the local unit should match the RSL of the vertical carrier of the remote unit, within ±2dB.
The RSL of the vertical carrier of the local unit should match the RSL of the horizontal carrier of the remote
unit, within ±2dB.
7. Check the XPI levels of both carriers on both sides of the link by checking the Modem XPI field of the Radio
Parameters page in the Web EMS. See Viewing the Radio Status and Settings . All four carriers should have
approximately the same XPI value. Do not adjust the XPI at the remote side of the link, as this may cause the
XPI at the local side of the link to deteriorate.
Note
In some cases, the XPI might not exceed the required 25dB minimum due to adverse atmospheric
conditions. If you believe this to be the case, you can leave the configuration at the lower values, but
be sure to monitor the XPI to make sure it subsequently exceeds 25dB. A normal XPI level in clear sky
conditions is between 25 and 30dB.
Deleting an XPIC Group (CLI)
In order to delete an XPIC group, you must first disable the group. Disable the group by entering the following
command in root view:
root> radio xpic disable group <group id>
To delete an XPIC group, enter the following command in root view:
root> radio xpic delete group <group id>
You must then assign non-XPIC MRMC scripts to the radio carriers that were included in the XPIC pair.
The following commands disable and delete XPIC group 1:
root> radio xpic disable group 1
root> radio xpic delete group 1