The model IFMR accepts a frequency input and controls a single relay (SPDT) based on the value of the input frequency. The trip frequency can be set to any value from 0.1 Hz to 25 kHz. The IFMR can be set to trip on over speed or under speed (including zero speed). Offset and hysteresis values can be incorporated into the trip setting to eliminate output chatter. LED indicators for both the input signal and the relay status are provided. Two separate input connections for external pushbuttons are also provided. One external input overrides the trip detection function and holds the relay in the release state as long as the input is pulled to common. The other external input clears a latched trip condition when pulled to common. The IFMR utilizes a seven position DIP switch, a rotary switch, a pushbutton and two indication LEDs to accomplish input circuit configuration, operational parameter set-up, input signal and relay status indication. The input circuitry is DIP switch selectable for a variety of sources. The indication LEDs are used during normal operation to display the input signal and relay status of the IFMR. These LEDs are also used to provide visual feedback to the user of the current parameter settings during parameter set-up.