... protocol stack;3.Low power consumption, provide sleep mode, scheduled on line/off line mode;4.Metal shell, provide IP30 protection; ... 1900 MHz- Communication Port: RS232 or RS485 (Option)- Power Save Mode - Software: Center Manager - Supply voltage: 5-36V DC - Dimensions ... protocol stack;3.Low power consumption, provide sleep mode, scheduled on line/off line mode;4.Metal shell, provide IP30 protection; ...