1. GPRS Module Settings

a. Check whether serial parameter conforms to working parameter of GPRS module

b. Check whether your serial line is OK

c. Check whether line connection and slots are OK

d. Check extending line is cross line or straight-through cable, and make sure signal transmission direction is right between PC serial and GPRS module

e. Check whether GPRS module has electricity and power supply is normal. The default power is 12V.

2. Instruction sending and returning

a. If can normally set up and read parameter, instruction sending and returning will be normal.If not normal,please apply for after-sale service

b. In transparent transmission and serial command mode, GPRS module can not send and return data after starting 15s. Normal response instruction of GPRS module is limited to within 15 seconds after the start of GPRS module and in AT command mode

3. Network connection

a. No network connection

(1) Check whether GPRS module has electricity: POW light is on and NET light flashes.
(2) Check whether SIM card is inserted before electricity.
(3) Check whether SIM card is in arrearage and.
(4) Check whether antenna is connected.
(5) Check whether target domain and port can connect to public network.
(6) Check firewall and antivirus program.

b. Lost connection

(1) Check whether antenna is connected;check whether server and network is stable
(2) Check user’s network environment and IP; static IP is better, which can avoid unknown error caused by router reassigning IP.

4. Communication and Data Transmission

a.PC tests one-way communication/abnormal communication : check serial setting parameter
b.If PC test is OK, please connect device NG: Check connecting line is cross line or straight-through cable; Due to the differences of users’ devices,line connection has its principle: TXD connects RXD, RXD connects TXD, GND connects GND.
c. Check serial parameter of GPRS module is matched with that of users’ devices.
d. Query users whether their software has high demand for time-delay. Our GPRS module is not suitable for application that has high demand for time-delay. It is normal to delay several seconds when using GPRS module.

5. Register Packet, Heartbeat Packet, Packing Time/Length and Auto Restart

Register packet is the first data packet when connection is established,which is used to identify and bind device by server.Heartbeat packet is used to maintain a connection. For packing time, GPRS module does not receive data in a certain period of time, then GPRS module packs data and sends the data. Packing length is temporarily unavailable. Auto restart is used under the passthrough/serial command mode.

6. SMS Remote Configuration Parameter

GPRS module supports SMS to send standard AT instruction and custom instruction.