OTDR fiber test

[Rayw]

Does anyone know can you run an OTDR fiber test with a Meraki switch still plugged in and running at the far end?

[Russ_B · Accepted solution]

I'm pretty sure you can only test dark fiber.  The simple Fluke tester that I have gives an error if it detects light on the fiber, and the manual warns that permanent damage is possible if the optical power is too high. 

The product support page for the Fluke OptiFiber Pro says "OTDR and OLTS testing should be performed on dark fiber only (no active signal, no active components in the link under test)"

Russ

[PaulMcG]

It can be done but the tester has to be made for it.  I've used an EXFO OTRD that had the ability, but there was a seperate port for testing a live fiber and a dark fiber.  There was a warning that using the port for dark fiber on a live one could cause damage.