... B-type USB ,1 Audio input/output ,1 RS232 & 1 RS485 Communication protocol Modbus RTU&ASCII Expansion yes RTC yes LCD ... Integral GSM 850/900/1800/1900 modemØ GPRS, SMS and CLIP supportØ Autonomous login into GSM/GPRS networkØ Different I/O configurations available ... 2 PWM channels(333Hz) optional Ø Pre-configured standard functions, e.g. on/ off-delays, pulse relay ,counters ,Watchdog function ,PI ...