The AX2550 is a high power electronics device. Serious damage, including fire, may occur to the unit, motors, wiring and batteries as a result of its misuse. Please review the User’s Manual for added precautions prior to applying full battery or full load power. Unless special precautions are taken, damage to the controller and/or power supply may occur if operated with a power supply alone. See“Power Regeneration Considerations” on page 37 of the Users Manual. Always keep the controller connected to the Battery. Use the Power Control input to turn On/Off. Without proper protection, a battery attached to an RC Radio may inject its voltage directly inside the controller’s sensitive electronics. This section will give you the basic information needed to quickly install, setup and run your AX2550 controller in a minimal configuration. The AX2850 is a version of the AX2550 controller with the addition of Optical Encoder inputs. The front side (shown in Figure 1) contains the buttons and display needed to operate and monitor the controller. The 15-pin connector provides the connection to the R/C radio, joystick or microcomputer, as well as connections to optional switches and sensors. Avoid extending the length of wires from the battery to the controller as the added induc- tance may cause damage to the controller when operating at high currents. Try extending the motor wires instead since the added inductance on the motor side of the controller is not harmful. Connect the R/C adapter cables to the controller on one side and to two or three channels on the R/C receiver on the other side. If present, the third channel is for activating the accessory outputs and is optional. When operating the controller in “Separate” mode, the wire labelled Ch1 controls Motor1, and the wire labelled Ch2 controls Motor2. When operating the controller in “Mixed” mode, Ch1 is used to set the robot’s speed and direction, while Ch2 is used for steering. See “R/C Operation” on page 109 of the User’s Manual for a more complete discussion on R/C commands, calibration and other options.