Profile: Crosstar, LLC. manufactures controls, telemetry and supervisory Control & data acquisition equipment for the water, wastewater and environmental control industry. We offer ATU advance telemetry unit, which is made up of individual modules that plug together to form the desired control and telemetry unit. Our liftstar system features computer controlled SCADA systems for less than the cost of a simple alarm dialing system. We design MD-201 bell 202 modem with DF1 to HDLC protocol converter, which is a half-duplex frequency-shift-keyed audio tone modem with an integral protocol converter.