1. GPRS Modbus RTU 2.Support RTU extended protocol 3.8 Digital inputs, 4 relay outputs GPRS Modbus RTU, MODBUS RTU, gprs rtu, gprs remote terminal unit F2164 MODBUS GPRS RTU Technical SPECIFICATION F2164 GPRS RTU is a wireless Remote Terminal Unit(abbreviation: RTU).It has multiple functions (analog input,relay output, digital input, digital output, pulse counting and wireless data communication, ...