Single Optical Beam Sensor (transmit and receive units): This sensor is used to conserve battery power. When sensors are used the antenna always stays in “sleep” mode until the beam between the sensors is broken. When the beam is broken the antenna turns on for a fixed amount of time and then turns off (can be changed via the software). This is very useful in applications where the batteries cannot be charged on a regular basis, in areas where solar panels cannot be used effectively or in high power consumption units.
Double Optical Beam Sensors (two pairs of transmit and receive units): Two sets of sensors can be used to determine the direction of animals generating In/Out data. The sensors are positioned on each side of the antenna and, depending on which sensor beam is broken first, the corresponding direction is then added to the identification/day date/time record. This method also helps in conserving battery power since the antenna is only turned on when either the sensor beam is broken.