... Messenger SMS Relay-- --Your ideal of Solution for : Remote Control,Monitoring & Alarming!x-Messenger- Expandable GSM/GPRS PLC incorporates a wide ... Interface no Ethernet no Data logging optional Interface 1 B-type USB ,1 Audio input/output ,1 RS232 & 1 RS485 ... g. on/ off-delays, pulse relay ,counters ,Watchdog function ,PI controller etc..Ø Logic functions-AND, OR, NOT, XOR……Ø Standard configure soft ...