I Tried also to pair my Vortex T1960 with my edge 520 but it doesn't work as expected.
I read elsewhere that despite the vortex brake send data (including power) under wireless ANT+, Tacx used until recently proprietary (or encoded?) protocol for their Vortex Computer or to the PC Tacx Training software or Cycling Apps.
From mid 2015 Tacx opened [rearranged under ANT+ FE-C standard] their protocol to third parties software (Zwift, Trainer Road, Kinomap Bkoolbut, ..) but, only for their range of products called "Smart" Trainers that are ANT+ FE-C certified!
then for "old" ergotrainer such as T2170 or T1960, EDGE 520 can receive ANT+ signals but cannot interpret them as powermeter data as not properly ANT+ formated. (the same appears for my Fenix 3 or other Garmin able to find "normal" ANT+ standardized powermeter)
I don't think TacX will put effort in old I-vortex now that they have their Smart trainers line.
Maybe you can only buy the Vortex "smart" brake T2181 but I don't know how it could fit on T2170 stand (and Tacx might be reluctant to give their Interface documents)
