Re: RS-485 Cable impedence mismatch


As often is the case, it was not a case of one thing being wrong, but
several. In addition to being the wrong impendence, for about 450ft of an
underground run it was in the same conduit as the electrical - which, by
the
way, was also about a 750ft total run. Of 220v on 14/3 NOMEX. Running
lights, a 1500w space heater and a 1/2 hp gate opener. And they wondered
why the lights were dim... Anyway, replaced both low and high voltage
cables, fixed a really nasty ground loop and what do you know - hardly any
transmission retries anymore. The software is still an absolute POS
though
- and the hardware appears to have been designed by cutting and pasting
from
cookbooks - "A" has an output, "B" has in input. They automatically
should
work, right? <grin>

Thanks to everyone for their help and suggestions; now it's time to go
appease an Marine Major who has a limited understanding of the word
"patience."

--
Hal
I would say it was just the ground loop....


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