Do I have to care about USB suspend mode or will the mbed device handle this automatically in the background? I'd like to do some measurements and it's important that the devices controlled by the mbed run properly. Thank you.

Which USB suspend mode?

I'm a newbie and maybe I haven't undrestood it the right way. I think according to the USB standard a USB devices has to switch to suspend mode when there's no activity on the bus for 3ms. Does no activity mean that there's no communication between my PC and the mbed or something else? In the suspend mode the device gets max 500uA from the PC, which wouldn't be enought for the measurements. I guess the mbed is handling this I don't have to care about it (like the mbed negotiates with the PC to get 500mA). If I have to make sure that the device doesn't go to suspend mode during a measurement, how can I do that?

Is mbed really an USB device? I would define it as a MC with the capability to communicate over USB. If you want to build an USB device out of it, you should take care of these specs. Anyhow, I don't think it is possible to reduce the power of the LPC1768 so that it is not consuming >500uA anymore. So if you really need to apply USB specs, you'll need lower power MCs

I conect the mbed on pins D- and D+ to the pc. For communication with the mbed I use a virtual serial interface. I assum so it is a USB device...

Actually I posted the question in this forum because I'm not sure about what part of the specs is handled by the mbed...