At 06:19 PM 1/31/99 -0700, Graeme Smith wrote:
>Hm... your still stuck with 4 lines..... I can see where ballancing
>the + and - lines allows you to reduce the capacitative effects, etc.
>
>But, that extra line is still expensive if it is needed on every path.

4 conductor phone wire is about the cheapest thing going.
I used this for a multiplexed smart sensor system. 1024 sensors on one line.
(I used to do alarms professionally)