Using Multi-Processor Mode with RS-485 and PC's

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Actually I did try my routine awhile back with VB2005 with W2K and it did work. In fact I think I was able to remove all the open/close statements, but I'll have to verify that again. Some day I'll convince the stick-in-the-mud dinosuars in my group to upgrade a little!!

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From my experience 9bit 485 comms driven from the ap PC is just tempting Murphy.
The reception of the 9th bit requires your ap to get to the byte before the next one comes in and overwrites the parity bit. Windows loves taking it's time and matters becomes worse if you've added a USB to serial converter : Then the bytes come in at a helluva rate.

Also if you want to log the data, or transmit it over Ethernet, Internet etc, you now have to use 16bits as these comms systems work in bytes. Future proof your design by supporting multiple media : go 8bit.

SLIP is a simple 8bit packetizer for your comms. As SLIP will packetize the data, simply use the first byte as the "to address".
bang! all done. future proof as well.
As for the source. All the source for a SLIP implementation is a available on http://www.opend.co.za . Delphi and GCC winavr c code.

Enjoy.
Murray Horn.

Murray Horn.
http://www.opend.co.za

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