Hi,
Which version of VISA are you using? Which version of firmware is in your TDS?
Driver can read following settings, when you are changing range (for channel1)?
":CH1:PRO:GAIN?", ":CH1:PROBEFunc:EXTatten?", "CH1:TER?"
I did not find any error in the code. If you need help, please attach spy log.
How make spy log:
1) Start>>All Programs>>National Instruments>>NI SPY
2) Start Capture (Pres blue arrow or F8)
3) Run getting started
4) Stop Capture (in NI-SPY should be all IVI and VISA function calls). Please Save this reprort in spy format and attach to forum.
Zdenek