If I was dealing with this....I would do RS422. The schemes using buggered up RS232 drivers to make RS232 daisy chainable or multi-droppable will seem clever now.....BUT THEY WILL COME back to bite you later.

The general incentive to support these buggered RS232 schemes seems to always come from the want to use a PC as the master and to use the COMM port to drive the serial link. But there is a reliable solution to this. Visit the web site of B&B Electronics and get the proper type of adapter to change the PC COMM port to RS422.

Michael Karas