Phase line meter? RPM?

[speedyebikenoob]

I've been trying to figure out a way to measure the rpm of my middrive cyclone motor. I noticed my motor controller has a wire labelled phase line meter coming off of it. Can anyone explain to me what this does? Could I use it to measure motor rpm? If so how would I go about doing that? It's a standard PWM motor controller if that matters.

 

[speedyebikenoob]

bump

 

[DogDipstick]

What do you plan to use to measure and or display this speed?

 

[speedyebikenoob]

an Arduino will receive the input and drive a stepper motor so it'll work like a tachometer in a car. My e bike is a middrive so I thought it would be cool. I've already done an analog speedometer for it the same way so I wanted to do the same for the tachometer.