https://devzone.nordicsemi.com/f/nordic-q-a/41169/nrf52840-usb-bulk-data-transfer-using-cdc-data-interfaceHi, I&#39;m trying to send and receive data to DATA interface that contains IN and OUT bulk endpoint (usbd_cdc_acm example). I&#39;m using libusb on the PC side. It seems like I can open the device but I can&#39;t read or write from/to endpoints. How can I useen-USTelligent Community 13Wed, 05 Dec 2018 15:26:34 GMThttps://devzone.nordicsemi.com/thread/160439?ContentTypeID=1Wed, 05 Dec 2018 15:26:34 GMT137ad170-7792-4731-bb38-c0d22fbe4515:f1c2e09e-c1ba-448d-8422-8d7c6edd7c9fASLI<p>I need to transfer data faster than serial port speed.</p> <p>I have few questions below.Can you please help?</p> <p>1. I started to modify the usbd example instead and I&#39;m trying to do data transfers in between endpoints, thinking that this would be faster. Is this correct?</p> <p>2.Which usb driver functions should I use for endpoint data transfer?</p> <p>3. What configuration would provide the highest data rate? I think MSD class is suggested for this but is BULK endpoint data rate with MSD class faster than BULK endpoint data rate of a CDC-Data class?</p> <p>Thank you and Regards,</p> <p>Asli</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/160426?ContentTypeID=1Wed, 05 Dec 2018 14:55:28 GMT137ad170-7792-4731-bb38-c0d22fbe4515:9e779024-4b6a-45f2-ad65-b70ad36272e1Kenneth<p>I do not think that is possible because the OS likely enumerate the device as a serial port, then it is used by the system, I believe it will be the same with mass storage devices and human interface devices. Instead have you considered write input and output data over the serial port?&nbsp;</p> <p>Best regards,<br />Kenneth</p><div style="clear:both;"></div>