Super User is a question and answer site for computer enthusiasts and power users. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I'm working on a software development project that requires me to send signals to a device via RS232 port. Sadly the included utilities for transferring to and from the device would not work for mass distribution, so I'm left to writing my own. The included documentation doesn't really give any examples of the device's packet structure, and I would like to examine the packets sent to and from their included software package.

Does anyone know of a good program that would allow me to monitor packets coming to and from the serial port? Free is preferred, but not required.

share|improve this question
serial port communications traditionally don't use "packets" (like ethernet or USB data transmissions). tho that's not to say a modern serial port application couldn't layer a packet scheme on top of more traditional serial transmissions for its own purposes. – quack quixote Jan 28 '10 at 17:36
@~quack - The device I am using does use a packet scheme, though I didn't realize that isn't something inherent to serial port communications. This is all a bit new to me. – Heather Kordinak Jan 28 '10 at 17:50
welcome to the wonderful world of device programming... :) – quack quixote Jan 28 '10 at 18:11
up vote 8 down vote accepted

Portmon, from Sysinternals, will do what you need:

Portmon is a utility that monitors and displays all serial and parallel port activity on a system. It has advanced filtering and search capabilities that make it a powerful tool for exploring the way Windows works, seeing how applications use ports, or tracking down problems in system or application configurations.

enter image description here

share|improve this answer
Yes! This does exactly what I wanted! Thanks. :) – Heather Kordinak Jan 28 '10 at 18:59

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .