Thanks Jim

ja, it looks like down the road 'just' using the comm port would be too limiting. i've started to read through the links you provided - very educational. i tried to understand the equipment needed for a RS-485 solution, but i am afraid i haven't gotten it yet <s>

if i understand it correctly i would hook up (to the comm port) a rs-232 to rs-485 converter?! with this i can control up to 32 external devices (switch 32 light bulbs in the house <s>). if my cables are longer then 4000 feet i need a repeater right.

but, looking at the pictures of a converter, i don't see a place where you could connect 32 cables?! and if there is one, we're talking about low voltage - right. so i need in addition to the converter a relay of some kind to convert from low voltage to 110V right?!

so money-wise we're talking about a few hundret bucks to control 2 or 3 devices. does that sound about right?

Ps.: i sure like those stamps - they are cool!


>Hi Gunnar,
>
>You only have 3 outputs in your 9-pin port - TX data, RTS, and DTR. The TX pin is only 'active' while sending data, otherwise in is in the 'mark' (-) state. These are purely hardware functions, so you are somewhat limited in what you can do, regardless of method of software control. If you need more control or more devices look at RS-485 which you can drive from your pc - http://www.bb-elec.com/tech_articles/rs485_basics.asp for starters. Have fun!