SatSig topic:

Data CRC Error on iDirect HUB

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Feb 11^th, 2015 at 3:11pm

Please what could be the causes of Datat CRC Errors noticed on all remote of iDirect HUB, thank you

Feb 11^th, 2015 at 4:24pm

If all your remote sites are showing CRC errors on their received outlink carrier from the hub, then the problem is probably related to the hub uplink or interference into the satellite. If you have a test remote at the hub then look at the receive spectrum of the remote. Possibilities include interference (co-pol, x-pol, adjacent satellite, intermod) or the hub sending a low level or distorted transmit carrier.

If all the incoming burst signals into the hub are generating CRC errors then the problem could be the hub receive system or interference into the hub, either on the satellite or locally. Look at the hub rx spectrum carefully. Check the DC power supplied to the hub LNA/LNB is smooth.

To locate interference it helps to have a spare polarisation/dish to examine the x-pol spectrum and the spectrums on adjacent satellites. Talk to the satellite NOC if you can't find the problem. Document exactly what spectrums you see.

I don't understand "Datat"

I hope someone with iDirect experience will also give you advice here.

Best regards, Eric.

Jan 28^th, 2016 at 1:34pm

Hello. In case you are watching CRC8/32 the issue is in the HUB---> Remote broadcast as Erci had told you and if you are having Tx data CRC that means the issue is in your return carriers. So I believe you are having Tx data CRC, beside Eric adviced you could also check:
1) Bad P1dB on remotes.
2) In the Evolution version 13 you can configured the up C/N for the modcod you are using, check it if they are not to low for your MODCOD. In case it is okey and your remotes have power enough you can try pum it up 1 or 2 dB in order to avoide interference
3) In case you are using FH you can also check if data crc are in all your carriers or just in one (in that case you will understand that you are having interference in taht frequency) try fix remote in carriers, doing this you can find the remote that is causing issues

Best Regards