H1 card

[yasser]

Hi every one,
I am facing a problem with the H1 card, suddenly it gives an error and all the valves goes to IMAN mode in the entire segment and to solve the problem you have to reset the card . Did any body have a suggestion to avoid this problem?

Yasser Elbayaa
ACBC

[Robin Burnikell]

Hi Yasser,


Presumably your valves are under PID control. If the PID loop comunication is broken (tokens are not issued & recieved) this will cause the PID loops to go to IMAN, so i guess the question is why is the comuication being broken.

It could be faulty LAS function (H1 Card), wiring faults, etc. If the H1 card is the only LAS on the network then this will cause the loops to go to IMAN when the H1 card stops issueing tokens. If you have any H1 field devices that are able to be backup LAS' I would recomend setting these to do so while you contact your H1 card supplier for a diagnosis of the problem on the card. IF you still get all loops going to IMAN afetr activating a backup LAS device on the bus I would suggest there is a wiring/termination fault somewhere.

Hope this helps,

Robin

[rezabejd]

I agree, your hardware supplier is the best resource for troubleshooting this issue. One vendor's original genreation of H1 cards used the NI PCMCIA card, which had some known issues when used 24 / 7. Maybe you need a hardware upgrade.

I have heard "war stories" (form Mike Clark of SAIT) of circumstances where one device at a time had to be taken off the loop, until the offender was found. You may get off easy and find the problem with a diagnostic tool, like a 'scope meter (oscilloscope) or a Relcom tester. If nothing else, results from these will help your hardware vendor isolate the problem.

John Rezabek
BP-Amoco