Thanks for your reply

My app is a third hand app...

It is used to program the parameters into a taxi-fare meter (or taximeter, I don't know the English name)

I want to have a logging of what is going out (or into, for that matter) the serial port. I don't have acces to the code of the original app, it is provided to me by the manufacturer, I am a local distributor/installer.

I need to keep record of the activity of my shop when I am nopt around...

I guess I can launch the original app with a bat file or from within VB and capture the serial port and send the data to a file.

The Terminal could be a good idea.

If you need more info, OK, post!