Yes I used a _PS_DEBUG_ window in the same Page to trap the error and then used some very simple System.print("Text"); to determine what position the script was working to.

The System.print(t); just prints 'undefined'.

This script was the first step in trying to obtain a return string of the format 'Qaxcdef' read each of the values and then use these to drive logic in various Activities i.e. Power on, Selecting Inputs etc.

I've had a TSU 9400 for some time but decided to venture into two way communications using a recently purchased RFX9600. Both are on the latest firmware versions (1.4.8 and 7.3.3). I could replicate the script in each area that I need to use it, but thought using a Library was a lot neater.