Thanks Scott, Unfortunately there isn't any handshaking available. The device I'm talking to is in production. It is on a RS-485 bus, which allows a number of serial devices to be on the same line. The "mark" parity raises the parity bit, which is a signal to all the devices that the next byte is an address from the host and to listen. It is a protocol that apparently is in use with a number of devices, but it still is a pain. Now if I can get National Instruments to handle it. They do have an RS-485 card, but that isn't an option either, a lot of this is being done on laptops in the field (remote mountain tops, etc.)
I've got it running pretty reliably now (don't notice any errors when running it in "continuous run" mode, and this is worst case. When there are a number of the devices on the bus it actually slows down their response a little. Well, I'm getting glared at as I'm sitting in my car in a Starbucks coffee shop parking lot using the T-mobile connection. DOn't need _any_ more coffee today, but I am using one of their parking spots. Putnam Monroe Senior Engineer Summit Technology Putnam Monroe
