Greetings List.. I'm a real newbie to PLCs and having trouble deciphering what software to use to communicate with and probably modify a program in a 90-30. It's a 10 device rack with embedded CPU (I think a 323). I originally bought a serial to USB cable and Logicmaster 90 Software from PLC trainer. I have recently ordered a straight serial/serial to try next. With the Logicmaster disc, I also got VersaPro 1.1. Anyway, my PLC was fault stopped, and I could verify such when VersaPro said I was connected. I could click and open the fault table, but when I clicked clear, I got a "maximum users for this port excedded" fault (or something similar). I tried connecting with LOgicmaster 90 software, but when trying to get in with that, my computer locked up so tight that I had to crash it to shutdown. I'm using XP home-SP3. I see software called "Simplicity ME" and "Proficy ME" out there for purchase or even free downloads, but don't know which way to go next. Any suggestions? Thanks, Tom