FreeWave IOE-4404 I/O Expansion Module can be added to a radio base for serial base I/O. Universal channels can be configured as a digital input, digital output, analog input, analog output or sensor power. Up to 15 expansion modules can be added to a radio base. With native support of 4-20 mA, 1-5 V and 0-10 V transducers with loop power. The Serial Base has a wired serial interface providing up to 192 I/O points to an existing RTU, PLC or other devices with serial communications.