I'm doing the same thing that your trying to do. I haven't got everything working quite right yet, but here's how I'm approaching it. First, decide whether you want a fixed length message or a variable length one with a terminator (or prefixed byte count). On the VB side, use the MS Comm control. If you have a fixed length message, set the rthreshold property to the length of that message. If you have a variable length one, set rthreshold to 1. This causes the oncomm event to fire when rthrehold characters are received. You can then use the input property (inside of the oncomm() event) to get your data. I hope this gets you started. Take a look at the VB help file for the Comm control.