Kinetis Microcontrollers中的主题 Re: Seeing multiple DTE Activated events - is this normal?

Seeing multiple DTE Activated events - is this normal?

rajbatra — Fri, 16 Oct 2015 00:30:15 GMT

I am using a k64F uP and implemented the USB CDC driver (KSDK+MQX). Up till now, I had been sending 64 bytes of data over the virtual com port and everything has been working fine. When I started sending data that is 280 bytes long, I noticed that I get multiple USB_APP_CDC_DTE_ACTIVATED events. Nothing bad seems to be happening, but am wondering if this is normal? I'm not a USB expert, and not sure if my Windows box is doing a flow control or pacing data - or if something weird is going on that I should be concerned about.

Thanks,

-Raj

Re: Seeing multiple DTE Activated events - is this normal?

isaacavila — Tue, 27 Oct 2015 22:48:21 GMT

Hello Raj,

As far as i know, this event is sent from Host terminal. I receive an USB_APP_CDC_DTE_ACTIVATED event every time i open a new terminal when using TeraTerm, but i do not receive more than one event eventhough i received more than 280 bytes.

You should pay attention on your Host terminal rather than USB CDC example.

I hope this can help you.

Best Regards,

Isaac

Re: Seeing multiple DTE Activated events - is this normal?

rajbatra — Tue, 27 Oct 2015 23:20:44 GMT

Hi Isaac,

I ended up figuring out the issue and yes it was on the Host terminal side. When I would vary the timeout on the connection on the host, internally, it was doing something that would trigger these events. Many times I would just assert the same port timeout value, but internally it would still generate the event. So, I created a wrapper that would ignore setting the same timeout value and this fixed it.

Thanks,

-Raj