What ESCs Support Motor RPM Logging?

Hi, I am using ArduCopter v3.3.3 right now, and I would like to obtain RPM readings for the motors. I saw that there are several ESC messages defined in the firmware in the data log code. They include motor RPM as one of the logging variables. But my IRIS+ does not log these ESC messages currently. I was wondering what kind of ESCs could enable the RPM logging for these ESC messages.