Question 1: What if the serial port is occupied? You can change the serial port you want to the specified serial number through Windows Device Manager.

Now many serial port softwares support automatic serial number identification, such as Gesi bonfire serial port assistant, SS and so on.

Question 2: I wonder why the serial port is occupied? Isn't that what it is? If yes, what did you do on the computer before the accident, what did you download, and what was unusual? If you think of anything, ask me. If you don't know how it happened, it is recommended to restore the system or reinstall it. Win78 10 Restore the system, right-click the computer and select Properties, and select System Protection and System Restore on the right. Follow the steps. If you have recovery software, you can also use software and image backup to recover the system.

Question 3: Why do you prompt that the serial port is occupied when using the software? First, select the correct door lock type and communication port in System Settings-External Device Settings-Door Lock Card Machine Settings. If the door lock manufacturer requires it, you need to enter the hotel logo and password. Close irrelevant programs, such as the business card printing program for door locks, and only open the software. When using external devices, other software may also use serial ports. If there is such a hint, please refer to the above method.

Question 4: How to release the occupied serial port and switch to RS232 for USB conversion?

Plug USB into each other once and it will definitely be released.

Sometimes it is because of the chipset problem that once the port is occupied, it will not be released. It's hard to solve.

Question 5: Ask for help. How to disconnect the serial port and make sure it is occupied? Or does it not exist at all?

If there is, it should be the RS232 serial port DB9 on the chassis.

Question 6: What if the serial port in the room is occupied? You can change the serial port you want to the specified serial number through Windows Device Manager.

Now many serial port softwares support automatic serial number identification, such as Gesi bonfire serial port assistant, SS and so on.

Question 7: What's the matter that the serial port of the computer is always occupied? Go to Device Manager and delete all unnecessary serial ports.

Question 8: What should I do if the serial port of the serial port debugging assistant is occupied? Open Device Manager to see if there is a serial port. Secondly, see if there is any other serial port software that can open the serial port and then restart the computer. You can use the serial port software that automatically detects the serial port, such as the serial port assistant of Gesi Fiberhome, to automatically identify the available serial ports.

Question 9: Ask the program how to judge whether the serial port is occupied or not. If you are using a serial port, use CreateFile to determine the return value.

If all available serial ports in the system are listed, and it is judged that those serial ports are occupied, then HKEY _ local _ machine \ hardware \ equipment diagram \ serial ports can be judged from the registry.

Question 10: The notebook uses a serial port conversion line, prompting that "the current serial number is occupied"? What do we do? Select the u *** serial device in the device manager, and you can change the serial number occupied by the converter in the advanced settings.