SatSig topic:

Linksat SAT keeps flashing on W3A modem

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Jan 5^th, 2007 at 4:16pm

Hello everyone!

I use the w3A service with a Linkstar modem.Works fine, until recently when I took the modem for maintenance. Now the SAT light blinks endlessly.

Does anyone have an idea of what the problem may be?

Best regards
Bablo

Jan 5^th, 2007 at 6:22pm

I suggest you contact the repair people and also the service provider for advice.

If the box MAC address has changed you will certainly need help from the service provider.

If the configuration has been altered, then you will need to change it back to what it should be for you. There is a savebootparms string to type in. Ask the service provider if not known.

Slow flashing indicates you have found some similar satellite signal. If you dish has not moved then you are likely on the correct satellite. Look for a BER with 3 or 4 zeros after the point, like 0.0001 to 0.00005

Fast flashing means that the correct carrier has been detected. Look with tclgets to see if pcrpid=true. Shortly after this it may start a self commissioning downloading process from the hub. If nothing happens, check the transmit cable is connected correctly and then that the BUC power is enabled. You MUST NOT get the cables crossed over or disconnect or connect the cables while the power on. There is also the possibility that the terminal has been temporarily disabled by the hub. Tell them you want to start up again. They need your side ID and box MAC address.

Slow flashing suggests you have found wrong satellite or wrong carrier or used a boot parameter input string that does not match the carrier from the satellite.
For examples of savebootparms strings see here: https://www.baseportal.com/cgi-bin/baseportal.pl?htx=/steve_murphy/satellites/sa...
You must type it all on one line and make no errors.

Best regards, Eric.

Jan 6^th, 2007 at 11:28am

Dear Eric,

Thanks for your professional explanation. I am sorry I was not more detailed.

The modem is fast flashing.

The MAC address is still the same.

The BER is 0.0001648564

The dish was not moved although we worked on it while trying to be sure the LNB was ok. So except a little shake may contribute to this behaviour.

The boot parameters were not modified.

One thing I fail to mention is that sometimes if it is left for a long time (about 40-50mins) without any LAN cable connected, the SAT becomes stable and then you can access the Internet and the speed is ok. I am using it now although I have spent hours watching it blink.

As it is currently stable, tclgets only shows some figures.

I have written to the service provider but I have not got a response yet.

From your experience, what would you suggest I check again?

Thanks once more for the time taken to help.

Best Regards

Jan 7^th, 2007 at 5:02pm

Communication with the hub is my recommendation.

You say that after a 40-50 minute delay with no LAN connection, that all becomes normal. The hub should be able to see what is going on and test your site, I can only make guessing ideas from here, like intermittent connection in transmit cable, a too high or too low transmit level setting, wrong burst timing (so it overlaps someone else's burst), interference on your return link frequency.

If the Linkstar modem RCST box resets itself spontaneously from time to time I believe this indicates a hardware fault, provided that the mains supply itself is not intermittent. Following a reset, the self test sequence occurs and soon the rx should go through slow and fast flash and then steady green.

Check the config, e.g.
https://www.link-sat.net/linkstar-command-pconf.htm
at both sites and look for differences.
wxw
Best regards, Eric.

Jan 8^th, 2007 at 3:47am

Dear Eric,

Thanks. The problem was that the SAT light was taking a long time to become steady green.It has improved now, or maybe I should say normalised, as far as I can see.

Didn't really do anything to it than return tx power to -30 in the bootparm (it was changed to -19 while first trying to troubleshoot by the engineer) and checked the connectors on the Rx cable(we just fitted a new one).

I did not receive any reply from the service provider till now, although they may have done something about it at their end.

Your assistance is appreciated and more than that your forum which has been very useful to me and several others.

Do you know of any company in Nigeria that repairs modems?

Jan 8^th, 2007 at 8:40am

The transmit power level out of the Linkstar RSCT modem needs to be just sufficient to make the BUC transmit the required signal. Too low and the signal to the VSAT hub teleport will be too weak. Too high and it will distort the signal itself and cause interference on adjacent frequencies. The level will be high but the bit error rate will be bad and the bursts may not be decodeable at the hub. The adjustment is in 0.5 dB steps. The set level will depend on the length and type of the IFL cable.

Read more here https://www.satsig.net/linkstar/linkstar-vsat-rcst-installation-manual-2005.pdf about possible diagnostics for transmit problems.

Try repeat -t 1000 tb to see what bursts are being transmitted, if anything.

Do prt termexec and look to see if Enabled=true
wxw
Best regards, Eric.