Jiabo gp-c4 17 is a thermal printer, and the port setting depends on the type of interface you use. In general, you can set the port as follows:

1. First, confirm the interface type you use, such as USB, serial port and Ethernet interface. If you are not sure, you can check the instruction manual of the equipment or consult the manufacturer.

2. For USB interface, insert USB data cable to connect printer and computer. The system will automatically identify and assign a virtual serial number. You just need to select the serial number in the printer driver.

3. For serial interface, you need to connect a serial cable between the printer and the computer. Then, select the corresponding serial number and baud rate in the printer driver.

4. For the Ethernet interface, you need to connect the printer to the network and configure the IP address in the printer's setup menu. Then, specify the corresponding IP address and port number in the printer driver.

5. Finally, make sure that the driver is installed correctly and set and configured according to the requirements of the driver.

Please note that the above steps are for reference only, and the specific setting method may vary depending on the printer model and driver. It is recommended that you refer to the printer's instructions or contact the manufacturer for more accurate setting instructions.