The device cannot read the history
Check if the ‘recording time’ on the basic settings page of the configuration software is set. The default is 0 (no recording), and the time can be set to 5-255 minutes.

Device time cannot be read correctly after the device is powered off or shut down
In the configuration software basic settings page, select the calibration mode as "automatic", then set the device's SIM card number, reboot, and wait for the device to register to the card and then read the time is normal.

The history was read at the wrong time
Open the configuration software and write device time to PC time in the basic settings page

Send SMS instructions to the device and the device does not response
1.Look at the flashing of the signal light to determine whether the device has registered the signal;
2. Is there any error in the device password, default 1234, if it has been changed in the configuration software, the new password should be used;
3. Is there any error in the short message instruction? Notice that there is no "+", and "#" is under the English input method;
4. Whether the mobile phone card in the device has the SMS function enabled;
5. If you use SMS APP to send short messages to the device without reply, please check whether the mobile phone has the right to send short messages and make phone calls to SMS APP.

Device not registered to signal
1. Check whether the external power supply is connected or not, or whether the external power supply is power-off.
2. Check whether the module version and the card in the device are universal or not, and whether the module model (2G/3G/4G) installed in the device is correct. For example, in China, 2G devices do not support Telecom 
cards, 3G devices do not support mobile cards, and 4G devices support all netcom.
3. Whether the SIM card is loose or not;
4. There is a problem with the card slot contact of the device.adjust higer the pins of the card slot with a tweezers,and install the card again

The timer of the equipment itself is inaccurate
Open the configuration software - communication settings - communication type, not selected "definition protocol"

In working mode, device does not respond to Modbus commands.
1. The device ID is not set. Solution: In the configuration mode, enter the parameter setting page of the configuration software, set the device ID, and then return the device to the working mode. (Using our cloud platform, the device ID is filled in by default. );
2. The device ID setting is incorrect. The slave address of the command should be the same as the device ID.

The device has triggered an alarm but does not send an alarm message/call
1. The device is not "armed". Please use the SMS command or the configuration software to "arm".
2, the battery voltage is too low, can not send text messages, please connect the external power supply to charge the device;
3. The format of the telephone number is incorrect, and the country code should be added, for example, China is 0086.
4. The GSM signal is too low;
5. The SIM card in the device is in arrears.

The temperature and humidity of the device are not displayed on the cloud platform.
Open the configuration software ---> DO / TH settings ---> TH settings, check whether the "Enable" is Ticked.