How do I set and delete the center number for my GPS Vehicle Tracker GT06N to cut off/restore oil by SMS command?

In case the vehicle is stolen, the users can send SMS command to cut off the Petrol/Electricity to stop the vehicle from moving. Note: to ensure the safety of the driver and the vehicle, this command can only be used when GPS is located and driving speed is less than 20km/h or the vehicle is not moving. The users can also send SMS command to restore the Petrol/Electricity so that the vehicle can keep moving.

Set the center number:

If you want to cut off/restore oil by SMS command, you have to set a center number firstly. Only the center number can send the cut off/restore oil command to the device. You can set your own mobile number as center number. 

The command for setting center number is: 
CENTER,A,mobile number# 
For example:CENTER,A,15942703401# 
If set successfully, there is an “OK” reply message. 

Note: Only the SOS number can be used to set center number successfully.

Delete the center number:

SMS command to the device to delete the center number. 

The command is:CENTER,D# 
For example:CENTER,D# 
If set successfully, there is an “OK” reply SMS. 

Note: Only the SOS number can be used to delete center number successfully. Only SOS phone number can send this command successfully to set the center number. There is only one center number can be set.