You can always invert a TTL signal easily, if that is the approach you want 
to take.
----- Original Message ----- 
From: "Vic Fraenckel" <victorf@windreader.com>
To: "PICMIT" <piclist@mit.edu>
Sent: Saturday, April 22, 2006 9:27 PM
Subject: [EE] RS232 multiplexing


>I need to multiplex one RS232 serial port to one of four RS232 ports. Can 
>this be done? Can a TTL Serial port be multiplexed to 4 TTL Serial ports? 
>Some TTL devices require inverted signals and some do not. How would I 
>handle this? Standard Baud rates to a minimum of 9600. Computer control of 
>port selection.
>
> I want to build this my self not purchase an off-the-shelf solution.
>
> Any enlightenment will be appreciated.
>
> Vic
> ________________________________________________________
>
> Victor Fraenckel - The Windman
> victorf ATSIGN windreader DOT com
> KC2GUI
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