Windows 11 - Real COM Port doesn't work but connected to virtual port it works

Question

Hello! Recently I tried using my laptop to program a syringe pump over RS232 with LabVIEW. I connected the device with a CH340 RS232 to USB cable with my laptop and tried to communicate through the COM port. After connecting the device to my laptop it also shows up in the device manager but it seems that I'm unable to open the COM port for communication. I also tried using PuTTY to communicate, but it also didn't work. I checked and installed the most recent drivers through the device manager and also installed them manually to be sure. When I connect my laptops COM port to a virtual one with Virtual Serial Port Driver (still connecting the cable to the same physical port of my laptop) I can use it and my program works with no problems. When I close the virtual port and try to use my real COM port I run into the same problem again, where I can't use it for communcation. Anybody had this problem or know what I could try?

Answer 1

Hi Leon,

Thanks for your post. Can I know have you loctated to the Device Manager-Ports and see any warning information below, such as the following yellow triangle. If there is a yellow triangle next to "Prolific USB-to-Serial Comm Port (COM X)". That means correct driver version is not installed. Kindly narrow down if it is related to driver firstly.

Best Regards,

Ian Xue

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