Hello and thank you for the post.
To invert your waveform in PS6 you can use the math channel function
Click on Tools>Math Channels and Invert A or B from the Built in math channel menu
- Image 1
To create your own "invert" math channel you can click on Create and type the formula -A to invert channel A or use any other letter to represent the channel you wish to invert
Could you also try PicoScope 7 Automotive here
https://oem.picoauto.com/p7beta/download
To invert a waveform in PS7, click on the desired channel option button and select Invert
- Image 2
I hope this helps, take care.....Steve