Opto-iso
Opto-iso
(OP)
I have an AB plc5 with remote racks which intermittently giving me rack fault. Nothing we've done so far works. We even had a rep from AB to come out to to look over our DH+ network, but he's stumped. At this point I'm entertaining the idea of isolating my discreet I/O field wiring, and wondering if any one has had good experience with a particular brand/type of isolator. Thanks,





RE: Opto-iso
Roy
RE: Opto-iso
RE: Opto-iso
does it happen during operation or all the time?
The worst things that usually happen in panels is the terminals get loose. I would get a maintenance guy to go through the panel and retighten terminals. Make sure the maintenance guy looks for frayed wiring.
RE: Opto-iso
RE: Opto-iso
Remote IO Adaptor Module User manual
1771-asb
1771-um001_-en-p.pdf
Is there a lot of vibration? Are your cards locked in by the tab on the front of the rack?
intermittent problems are obviously hard to find.
RE: Opto-iso
Roy
RE: Opto-iso
There's no vibration whatever to the chasis in question. And yes, cards are locked in with the tabs.
I have been using the -asb user manual as a guide.
Roy- that's a good catch on that Modicon. Isn't it typical how a simple installation error would cause so much grief! Just so happened, yesterday we corrected a different dh+ network problem stemed from incorrect setup of a pair of Ecotec fiber to copper converters.
Any thought on what would work well to isolate i/o wiring?
RE: Opto-iso
Ethernet and RS485,(and most PLC stuff is just RS485 hardware no matter what screwball name they toss on it), both have gone flaky on me MANY times.
I think you may need to change whatever has the actual control hardware. As much time, as you no doubt have spent on this, with no clear solution, or improvement, would point to that now as the most effective next step.
Keith Cress
Flamin Systems, Inc.- http://www.flaminsystems.com
RE: Opto-iso
What about this thread, it talks about how to cut down on noise, it for a slc but there would be a similar product or the same for plc5 output cards that could be causing these problems.
"How to check voltage on a 1746-OA16 card"
If you have eliminated the problems in the manual on the asb module then it has to be a noise maker.