Thread: NMEA mutiplexer
View Single Post
  #14   Report Post  
Glen
 
Posts: n/a
Default NMEA mutiplexer

On Wed, 22 Oct 2003 14:02:52 GMT, "Glen Wiley Wilson"
tempted fate with:

On Wed, 22 Oct 2003 09:19:20 +0200, "Meindert Sprang"
tempted fate with:

"Glen Wiley Wilson" wrote in message
news

Again, I would never hook an RS-422 and
an RS-232 circuit together directly. Your mileage may vary.


In general: you can connect a RS-232 output to a NMEA RS-422 input by
connecting teh TX or OUT from the RS-232 to the + or 'A' from an NMEA in,
while connecting the - or B from NMEA in to the ground of teh RS-232 output.
The other way around (RS-422 out to RS-232 in) will mosty not work.

Meindert

Yes, I have seen or done both. I even understand why it works that
way. I was merely stating a policy. When I spec something for
navigating a boat it has to be bulletproof, not a marginal "generally
works" type of thing.

I forgot to mention that NMEA listeners are supposed to be isolated,
so it should be perfectly fine to attach an RS-232 talker to an NMEA
listener. I'm just not sure everyone implemented that particular
feature, given the workmanship I've seen in the instruments I've
cracked open. So, for the record, when speaking for public
consumption, I prefer to play it safe.

But, as I said before, I'm not an expert and I'm willing to be
educated if I'm wrong.

__________________________________________________ __________
Glen "Wiley" Wilson usenet1 SPAMNIX at worldwidewiley dot com
To reply, lose the capitals and do the obvious.

Take a look at cpRepeater, my NMEA data integrator, repeater, and
logger at http://www.worldwidewiley.com/