USB CDC ACM Example is not open port

[nhamtung]

Hi there, I really much in trouble with USB CDC ACM. So that would be great if you can help me out with this: I upload the "USB CDC ACM" example (SDK verison 15.2) to my nRF52840 development kit. In the device manager, the nRF52840 development kit appears as "nRF52 USB CDC Demo (COMx)" However, nothing work. The port state is close (led 2 is Off) and when i press button 1, no data was sent from the development kit. I tried my best to figure out the problem but so far no good. Really appreciate your help!

[razor_et]

Hi ,nhamtung :  

I have the same problem with you , do you solve it?? 

[Jared]

Are you using the right USB port? The appropriate one is the nRF USB port not the "regular" USB port that is connected to the interface chip. 

[razor_et]

I had solved this problem. I found my serial tool did't choose open DTR , after open it ,USB CDC ACM port was working  well.

Thanks for your reply.