The speed output signal is typically used in conjunction with the SELCO M2000 or M2100. This signal is used by the M2000/M2100 to provide crank disconnect at 33% of nominal speed and over speed alarm (and optional engine shutdown) at 115% of nominal speed.

The M0500 also includes an output which tells the M2100 Emergency Controller whether or not the generator output voltage is within the nominal range.