Question: how to use otdr testing?
Answer: Turn on OTDR and allow time to warm-up.
Clean all connectors and mating adapters.
Attach launch cable to OTDR. Attach receive cable (if used) to far end of cable.
Set up test parameters on OTDR.
Attach cable to test to end of launch cable. Attach receive cable (if used) to far end of cable.
Acquire trace.