Ventech PTZ Controller Joystick LCD Security (Pan Tilt Zoom) Speed Dome Camera 3D,Keyboard to Control All Functions,Up to 128 Speed Dome Cameras,3500 Feet Maximum Distance Communication PTZ CONTROL LCD Display, Keyboard and 3-Axis Joystick Remote Control Pan/Tilt/Zoom of Dome PTZ Camera, can control pan/tilt rotation, iris, preset tour, pattern, Zoom-In, Zoom-Out and Focus Directly Preset Positions and Tour Groups,uses RS-485 protocol RS485 control 255 front end address and connect up to 128 devices simultaneously Good communication compatibility, built-in many kinds of agreements