5Figure 3: General UC5™ System Layout (Front Mount)4.2 Height Sensors Height sensors use an ultrasonic signal to measure distance to the ground or crop canopy. The number of height sensors will vary from a minimum of two to a maximum of six persystem. Three height sensors are normally used.4.3 Roll Sensors Roll sensors are important for measuring boom and sprayer roll dynamics. Two roll sensors are normally used for a UC5™ Spray Height Control system. The mounting position of the roll sensors vary from sprayer to sprayer depending onboom geometry and suspension.4.4 Position Sensors Position sensors are used to measure boom suspension position and/or cylinder position. The function of position sensors may be similar to that of a pair of roll sensors. The mounting position of the position sensors vary from sprayer to sprayer depending onboom geometry and suspension.4.5 Modules Normally there are three modules included: a control module, an input module, and avalve module. Module status is indicated by a LED. Shortly after power-up, the module should present agreen light, indicating the module is functioning and ready.