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Real RS-232 Cable Length Limit

Real RS-232 Cable Length Limit

Real RS-232 Cable Length Limit

(OP)
175 cable feet of STP between a PC comm port and the DCE--think it'll work at 9600, at 19.2k?  I'm not looking for what the specs say but what your experiences are.  Cut sheet for the cable says 40pF/ft @ 1.0 MHz.

Dan B

RE: Real RS-232 Cable Length Limit

Sure.

Oh..
40pF/foot... That sucks.

Maybe not.  If it doesn't, it's your crummy cable.

It's a hard call really as it also depends on your electrical environment.  I would imagine 9600 would be dependable. Maybe 19.2k with good cable. In a benign place.

Hopefully you are driving the cable with nice levels not some laptop with +/- 3V levels.

Keith Cress
Flamin Systems, Inc.- http://www.flaminsystems.com

RE: Real RS-232 Cable Length Limit

I doubt there's a commercial cable for this service, so your're talking custom cable.  That'll cost ? ?

If it's a dollar a foot plus connectors and labor, $200?

What about a couple 232/485 converters, one for each end, and 200' of twisted pair that you've already got lying around, instead?  Far higher probability of it working.

Dan



RE: Real RS-232 Cable Length Limit

If you use this cable spec you can get 500 ft distance.  experienced it myself.

Black Box EDDC

but on the - side it is expensive.

RE: Real RS-232 Cable Length Limit

controlsdude; You experienced it at what speed?

Keith Cress
Flamin Systems, Inc.- http://www.flaminsystems.com

RE: Real RS-232 Cable Length Limit

I believe most of interfaces were at 9600, some were 19200, and never above that speed. bar code scanners usually char length= 20 to 50. sometimes scales, conv speed up to 550 fpm, gap between cases 12-15 inches.

RE: Real RS-232 Cable Length Limit

I don't think you'll do 9600 at 175' over STP.

Current loop should work okay.

Mike Halloran
Pembroke Pines, FL, USA

RE: Real RS-232 Cable Length Limit

some applications that I did were up to 400 feet and at 9600 baud as far as I remember.  It all depended on main panel location and scanner locations.  This was with the black box eddc cable.

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