FREJA 300 connection problem 3

[lz5pl]

I need advice from colleagues with experience relay protection tester FREJA 300 from Programma Electric. Tester is more or less OK for our needs, but we have very unpleasant problem with communications to it.
Connection to the tester is via COM port only. In some days connection is established immediately, but sometimes we see on the screen of Freja WIN software message "Freja not found". After several restarts of the tester and laptop connection is established. When established it can run all day without crashes, but sometimes it crashes, mostly when "General" instrument is in RAMP-mode and ramping is stopped from the screen, not from binary input of the tester.

My question is to all colleagues who have experience with this tester - do you have similar problems, or it is some hardware problem of our tester.
We use laptop with native COM port and another with PCI Express-to-Serial card.

Local dealer is commercial company and cannot give us any advice.

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It may be like this in theory and practice, but in real life it is completely different.
The favourite sentence of my army sergeant

 

[ScottyUK]

lz5pl,

I can't directly answer your question, but I have had similar problems with Allen Bradley's old 1747-AIC serial converter. The underlying cause was that the unit was designed to work from a serial port built to the full IBM spec from decades ago. Most modern ports - and especially those on laptops - are limited in the amount of power they can deliver, which affected the converter because it drew power from the port. It would be worth checking any power management on the ports - one of my laptops allowed the converter to work OK when on mains power but became very erratic when on battery power. Things improved slightly when the power management was disabled.


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If we learn from our mistakes I'm getting a great education!

 

[lz5pl]

Thank you Scotty. I suspect similar problem, but cannot be sure without expert consulting. I already sent question to Programma Electric/Megger and hope to receive advice from the manufacturer.

By the way, we have local Bulgarian manufacturer of test sets. It happens that I was the relay engineer who worked with their tester with serial number 002. I faced so big problems with communication that I completed all my tests in manual mode from the hand-held terminal. Later when came back in Bulgaria I met manufacturer and informed them about the problem. They were very surprised, declaring that never had problems. But in fact they made all factory tests from desktop PC. Later they investigated the case and found that electrical levels on RS232 interface chip they use are such that most of laptops cannot feed them and get overloaded.

I am considering now the idea to buy industrial "Ethernet to RS232" converter, install it directly on the box of the tester and communicate only via LAN cable. May be this could help ...

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It may be like this in theory and practice, but in real life it is completely different.
The favourite sentence of my army sergeant