# Factory Setting and COM Port Allocation

### *Resetting to Holybro Factory Configuration*

Using  [Uprecise](/gps-and-rtk-system/h-rtk-unicore-um982/download.md#unicore-uprecise),  type the following commands, followed by ENTER on your keyboard, into the configuration command line:

* FRESET
* GPGGA COM1 0.2  
* GPRMC COM1 0.2 
* AGRICA COM1 0.2
* GPGSA COM1 0.2
* GPGST COM1 0.2
* UNIHEADINGA COM1 0.2
* config com1 230400
* saveconfig

### Default COM Port Allocation 

UM982 has three COM (also called UART) ports. The connection relationship of these three COM ports in hardware is as follows:

* COM1 <-> 10pin GH interface, connect to flight control
* COM2 <-> 6pin GH interface,
* COM3 <-> USB to UART chip <-> USB port&#x20;

In the factory default configuration, only COM1 port has GPS message output, COM2 and COM3 do not have GPS message output. (The fewer output messages, the lower the power consumption, which also helps to improve the receiving sensitivity of the module)

### Getting Data from USB Port

If user connects to Uprecise through the USB port and wants to see the real-time information of GPS satellite search, one needs to enter the following command in the command line box after connecting:

* GPGGA COM3 1&#x20;
* GPRMC COM3 1
* AGRICA COM3 1
* UNIHEADINGA COM3 1
* saveconfig


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