All the screencasts we currently have available are here: http://www.opto22.com/site/le_developing_your_app.aspx
The PAC Manager screencasts describes some conifguration options and debugging features. However, we do not currently offer a video that covers I/O unit's scan time. If this is the video that you are interested in, please, let us know. We are always looking for the next video idea and are always interested to know what is of interest to everybody else.
If you have other video ideas right now, you can enter our "Shoot This, Opto!" contest which is a contest where customers post video or screencast ideas. For more information, check out the blog post at this address http://www.opto22.com/rss/optoblog/2007/05/shoot_this_opto_1.aspx. Let me know if you have any other questions.
Thanks.
-kdowney