SatSig topic:

Asking for Urgent Support : S2A TX Sync Issue

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Mar 11^th, 2015 at 7:42pm

Dear Gents ,
I'm looking for urgent support from expert guy , as we have Linkstar HUB with expired End Of Life , so the last period we were planing to move all the customers to another platform , and we did and turned off the HUB for around 1 month , then 3 remotes asked to reactivate their terminals for short time to do some tests , but Cry

unfortunately when we did turn on again for the HUB , Remotes aren't able to sunchronizing to the HUB never .
Remotes are able to Rx DS but not able to lock to TDMA Carrier .(SAT LED fast blinking)
We reviewed all configuration for GCU , Carriers , ..so on
I believe it may the issue from ITDU or from GCU or may from RNCC , but i'm not sure which one exactly , so i'm looking for any one helping to troubleshoot those equipment and find the issue .
I can provide any information if required .
Many thanks in advance .

Regards ,

Mar 12^th, 2015 at 9:45pm

I left this for a day since I am not an expert on Linkstar. I still hope that others might comment here and help you.

I would verify that all sites are successfully receiving the outlink.

Next I would look on the analyser to see if any bursts were coming into the hub. Is the return link frequency slot clear of another new carrier ?

The manual says that 5 minutes may elapse with the TX flashing while the remote downloads software updates. Is this happening ?

Another thought... Has someone taken all the IP addresses you previously used for the remotes, or blocked them in a router ?

Best regards, Eric.

Mar 13^th, 2015 at 4:38am

Hi Eric ,
Thanks alot for getting in touch , appreciating .
Yep , all sites showing the same case , fast blinking , which means that they are receiving DS .
Regarding the return link slot , yep it is free for using .
"Next I would look on the analyser to see if any bursts were coming into the hub" , sorry i can't understand what is the required for this , how to collect these information , but i may give you an access to my system to check all configuration .
Modems are not downloading anything , even they are showing Down in the NMS , and regarding the manuals , if you can send it to me through my email , it will be very helpfull (also if you have the manual of ITDU , GCU ,IPE,...so on )
Regarding the IP , no one took them , and not blocked in the Router .
One more thing to add , when checked the interface of the router which connected to the GCU , it showing high number of received Errors , is that meaningful ?

Note : in the NMS , Remotes are showing Es/No 0 for both DS & US .

How to define if the ITDU & GCU are working normally ?

Thanks in advance .
email : okasha_sat@yahoo.com

Regards ,

Mar 13^th, 2015 at 10:51am

Hi,
before locking at the Hub config, did you checked that no one send in your outbound frequency(check this by make your transmit off in the modem and see your carrier in the analyser).

BRs,
Hafid

Mar 13^th, 2015 at 2:58pm

Hi Hafid ,

Thanks for input .
I brought my carrier down and checked the space , it is free .
What should be the range for the DS frequency in the qu-band ?

BR ,

Mar 13^th, 2015 at 9:44pm

Hi,
Put in the analyser the central DS frequency of your range;the corresponded DS of UP frequency configured in your outbound modulator( satellite operator gives you UP and corresponded DS frequency)
Also check in the analyser DS frequency of your inbounds
so you can have more infos about problem origin: hub and remote modem or RF part ...

you can join me on skype hafid.outaleb3 for more troubleshooting

BRs,
Hafid

Mar 14^th, 2015 at 12:42pm

Gents ,

I would to say thanks to Hafid for his time spent with me yesterday trying to investigate the issue , really appreciated .

Any one would to help me also will be a great manner .

Thanks to all .

Regards ,

Mar 14^th, 2015 at 2:02pm

Have the remote sites been freshly programmed with the appropriate configuration text line ?

It occurs to me that they might have given up trying with the configuration used a month ago and gone into some previous fallback configuration. Check pconf at the remote to see if the config is normal

Regarding watching what is happening at the hub. Having verified the remotes are receiving normally (i.e. TCMP showing normal with QPSK BER = approx 0.0001234 ref: https://www.link-sat.net/linkstar-command-tcmp.htm ) I would put a spectrum analyser to look at the return TDMA burst frequency area, e.g. SPAN=1 to 3 MHz. With spectrum analyser default settings you should see occasional flashes. ZERO SPAN or MAX HOLD can be used to record and study the bursts. It should be possible to see the incoming TDMA bursts.

Best regards, Eric

Mar 15^th, 2015 at 12:45am

Hi Eric ,
Thanks for getting in touch , and sorry for delay .
Yesterday i had a session with Hafid , and we checked together the configuration of both TDM & TDMA Carriers , and i showed him the DS on the Analyzer , it was clear without interference .
Also i used one RCST for test from my location , so it was showing the same indication (SAT LED fast blinking ) , also in the Analyzer it was showing bursting on the slot of TDMA Carrier .
But in the NMS it was showing Down and when displayed the status of it , it was reporting " RCST not allocated any GCU or carrier at this time " , i also connected directly to the RCST and through the commands TCMP & TCLGETS & ...so on , collected data was as below :
Rx synced : TRUE & NCR synced : TRUE & Watchdog enabled : TRUE & Tx synced : FALSE & TCL State : SORFSynced & PCR Error Discards : 104652 & Ldpc Bch : LOCKED & RxPower : -39 & Synced : 1 & BCHUncorrectedErrCount 4 & TimeSynced 16377 & EsNo 13.8 & UncodedBER 0.003899504
rcstlockinfo command is showing : RCST is unlocked
So according to the displayed , we supposed no issue in UP Chain .
So we are thinking the issue in Down Chain , so we supposed it maybe the issue in ITDU or in the GCU itself .
Tell now the acquisition process is failing , so it might be the issue in the timimng and syncronization .
What do you see ?

Thanks for helping and follow up .

Regards ,

Mar 16^th, 2015 at 12:11am

Gents ,

Pls if any one has the manuals of the GCU, ITDU ,...or ant part of Linkstar HUB , pls send to me via my email : okasha_sat@yahoo.com , as we lost the manuals .

Appreciating any helping from any good guy .

Thanks for all .

Regards ,