Thanks for the help, however it’s not quite what I required. My actual problem is I have written two VB applications (only prototypes at the moment) which run on separate PCs connected via Comm port 1. One of the applications performs a break event on its output line for a set duration. The other application can detect this using the OnComm error event. What I’m trying to do, is time the duration of the break on the receiving PC. The problem is there’s no event that detects when the break on the line is removed. I have an idea that I may be able to use an API call to detect the status of the receive line but I fear this may take to long as the time scale is in milliseconds.

Sorry for the original lack of info

Kevin Preston.