Tried the commands above, also the AUD command. No dice on any. It does not convert the command into a proper serial command. If I use "MLMatrixSwitcher|2~Switch~All~01~01", it sends a V0101 serial command to the 1616A. I was reading VideoStorm's RS-232 programming guide and it says that the 1616A will not recognize "Vxxyy"-type switch commands. It only recognizes "Cxxyy" "Oxxyy" or "Axxyy" as switch commands. All the other commands listed in the FAQ (i.e. AUD, VOLUP, VOLDOWN, MUTEON, etc.) return a "Failed to translate command into a valid switch command" error. I know it's not a communication error because I can control the unit perfectly using HyperTerminal. If you'd like to do a remote dial-in, I can maybe set something up for next week.
BTW: My VideoStorm Drivers are listed as version 3.75.40 and the Matrix Switcher Family program is version 3.75.14. I used Installation Assistant to try to install the latest drivers. Are these the correct ones?
Again, thanks for your help!