rs232/485 -> current loop - off-shelf solution?
rs232/485 -> current loop - off-shelf solution?
(OP)
In a coal mine, two devices are communicating at 4,8kbaud over two-wire rs485 bus. There's lot of noise (with a lot of lost bytes), because the power cables from AC-drives lay near, and there's not really a way to avoid it.
Unfortunately, I can't improve "communication skills" of devices (better cyclic codes and so on), they are third-party.
I think, a current loop (with relative high current) would be a robust solution in order to reduce the number of lost bytes. Are there some Ex-certified industrial current loop transcievers available?
Unfortunately, I can't improve "communication skills" of devices (better cyclic codes and so on), they are third-party.
I think, a current loop (with relative high current) would be a robust solution in order to reduce the number of lost bytes. Are there some Ex-certified industrial current loop transcievers available?





RE: rs232/485 -> current loop - off-shelf solution?
You would need to do the same with your current loop anyway.
TTFN
RE: rs232/485 -> current loop - off-shelf solution?
RE: rs232/485 -> current loop - off-shelf solution?
I don't mean 4..20mA loop. It's still digital, but 0 and 1 become, for example, -100mA and +100mA. When properly shielded and grounded (thanks IRstuff), it's more noise-proof.
Are there some transcievers available on the market? (It's not really sophisticated - some MOSFET keys, some op-amps... But it's for industry, must be something standard)
RE: rs232/485 -> current loop - off-shelf solution?
Wheels within wheels / In a spiral array
A pattern so grand / And complex
Time after time / We lose sight of the way
Our causes can't see / Their effects.
RE: rs232/485 -> current loop - off-shelf solution?
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http://www.tccomm.com/TC1530.htm
Wheels within wheels / In a spiral array
A pattern so grand / And complex
Time after time / We lose sight of the way
Our causes can't see / Their effects.
RE: rs232/485 -> current loop - off-shelf solution?
RE: rs232/485 -> current loop - off-shelf solution?
fiber optics. No need for all of us to do the
same research again.......
Cheers,
Rich S.
RE: rs232/485 -> current loop - off-shelf solution?
We use rs-485 in high voltage switchgear and in our switchyards etc. Some twisted pair and some down the "glass tube". A ton of really good info that is free to download concerning rs-232, 422, 485 etc is available here: www.bb-elec.com.
If your mind is made up about the current loop, I'm sure the folks at the above mentioned website can steer you in the right direction. They have helped us several times in the past and made life much easier.
Some of our twisted pair is in switchgears and switchyards near bus at up to 69KV and currents over 1000 amps/phase. It can be done.
Regards
Mike
RE: rs232/485 -> current loop - off-shelf solution?
RE: rs232/485 -> current loop - off-shelf solution?
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If we learn from our mistakes,
I'm getting a great education!
RE: rs232/485 -> current loop - off-shelf solution?
http:
Rod Lechelt
RE: rs232/485 -> current loop - off-shelf solution?