Low cost, low power consumption radio frequency transceivers are incorporated in barrier operator control systems for transmitting signals between an operator control unit, one or more remote control units, a diagnostic or calibration device and an obstruction detector. Similar detector devices, including such transceivers, may be employed in loading docks for detecting the status of dock levelers and vehicle restraint devices. Radio frequency communication eliminates the need for hard wiring and also provides for transmission of commands and status information between various control units.