An emergency vehicle uses a optical IR, LED or Strobe emitter to transmit a signal. The TOMAR STROBESWITCH™ receives this signal then activates its solid-state output relay. The access control relay output may be used to control security gates, fire department garage doors, and other devices. Signaling is optical by line of sight, and the TOMAR STROBESWITCH™ can operate indoors or outdoors, in bright sunlight, or in any weather. The unit is not susceptible to radio frequency interference, and uses digital frequency discrimination to reject unwanted signals, such as flashlights, flashing signs, etc.