[Top] [All Lists]

[TRLog] RS 232 voltages +0.08 or -11.2

Subject: [TRLog] RS 232 voltages +0.08 or -11.2
From: (Kevin Schmidt)
Date: Sun, 5 Dec 1999 01:02:58 GMT

You may want to check with the manufacturer since you may have a
defective board. My understanding is that RS-232 is required to have
signals between +3 Volts and +25 Volts for the space and between -3
Volts and -25 Volts for mark.  You might also want to make sure that
+12 Volts is getting to the motherboard.

73 Kevin w9cf

> From: "Guy Olinger, K2AV" <>
> New motherboard and extra serial card. Both are showing +0.08 or -11.2 volts
> reference chassis ground as their state voltages. The CAT port on the MP 
> talks> to this fine, but the cord I made up with the transistor, resistor and 
> diode
> circuit I built into the db9 plug from the TR manual just barfs.

> Do these need pull-ups from +12 (not on the DB9 socket anywhere) or is this a
> new interface level from Y2K and beyond and need a different circuit. Com 1  
> &> Com 2 are on the motherboard.

> Anybody run into this and solve it?

Kevin Schmidt,,
Department of Physics and Astronomy
Arizona State University, Tempe, AZ 85287-1504
(480) 965-8240 Fax: (480) 965-7954

FAQ on WWW:     
Administrative requests:
Feature Wishlist:

<Prev in Thread] Current Thread [Next in Thread>