This question comes via JD Buchanan.
You may need to ascend a tensioned line, like a guided rappel to fix something at the top anchor, or to assist a stuck teammate in the middle of the guided rappel. The two photos should give you a good idea on how to rig your ascenders. Key aspects of this system:

  • Route the foot loop through the carabiner so its aligned with the tensioned line.
  • Some PCDs that are not Micro-Traxion like, may not work.
  • Rig a Prusik or Tresse at the top if you expect to convert to descent in the middle of the rope.

Reference:CGI Assessment Monterrey NL Mex
Canyoning Professional Handbook pg 154