How do I know my input and output ports?

Open is to run cmd enter netstat an on it .

You can check your computer's port number by using the netstat -na command in the DOS window. Enter cmd in the operation of the computer, open the DOS window and enter the above command Enter to view the port number of the current computer. Here's how:

Equipment: Coupling Finger Duan Chunxiang Xiaoxin Pad Inch Computer;

Operating system: window7 ultimate.

1. Click Start in the lower left corner of the computer and select Run.

2. Enter cmd in the dialog box that appears, and click Run.

3. In the DOS window that opens, enter netstat -na and press enter.

4. At this time, you can see all the current port numbers of the computer in the data that appears.

You have a missing space between netstat and -an, so it will give you an error.

Switch to the desktop, press Win+X key combination, and select the "Command Prompt (Administrator)" command:

If you simply select the Command Prompt command, the following actions may result in an error:

After opening the DOS window, we usually enter the "netstat" command to view the simple statistics, where the port information is after the colon

When entering the "netstat -nao" command, the pid entry program number can be displayed in the rightmost column, so that we can end the program directly with the command:

Enter the "netstat -nab" command to get more information about the network connection, port usage, and program run

After discovering these abnormal ports and programs, you can first end the process tree and perform other detailed operations

If you need specific monitoring and control port use, you need to use third-party software, such as Jusheng network management and other software, which can intuitively and quickly realize port monitoring and control.

Start --Run ---cmd--- type netstat -an to see it.

If you're asking about hardware: the com port is a 9-pin connector on the motherboard.

If you are asking about the software aspect: com interface, it is recommended that you search for the design and application of com construction.