... public GPRS network.It adopts high-powered industrial 32 bits CPU and embedded real time operating system. ... 900: <33dBmGSM1800/1900: <30dBmRX sensitivity<-107dBmHardware SystemItemContentCPUIndustrial 32 bits CPUFLASH512KB (Extendable)SRAM256KB(Extendable)Interface TypeItemContentSerial1 RS232 port and ... 1 RS485(orRS422) port, 15KV ESD protectionData bits: 5, 6 ,7, 8Stop bits: 1, 1.5, 2Parity: none, ...