Feature 1 GPRS module GM3 supports low power mode users can use AT command to enter low power mode or can turn on automatic low power mode 2 Users can use the network AT command external GPIO and phone text messages to wake up which is convenient for power consumption when using battery power 3 When the GPRS module GM3 is used as the TCP CLIENT after the TCP successfully establishes the link it automatically sends a predetermined registration packet for the TCP server to identify the TCP 4 The registration packet data can be an IMEI code an ICCID code and custom registration data 5 GPRS module GM3 In the network transparent transmission mode the user can choose to let the module send the heartbeat packet The heartbeat packet can be sent to the network server or sent to the serial device 6 The network heartbeat packet is continuously sent to maintain the normal connection between the module and the server 7 The serial heartbeat packet is suitable for sensors that cannot actively push data to the server to actively capture sensor data 8 LBS base station positioning can obtain the location information of the GPRS module GM3 through the network of the telecom mobile operator conveniently querying the location of the GM3 and making up for the GPS positioning affected by weather high buildings locations and the like 9 GPRS module GM3 supports the second network link which is suitable for users who need to send data to two servers for data backup and remote