RE: [Libusb-devel] usb_interrupt_read error

[Johann G. <Joh...@gm...>]

Hi!

The below device descriptor shows that the "serial to usb cable" comes
from Metrologic. I suspect that this isn't a real "serial to usb cable".
The barcode reader seems to recognize that the cable is not RS232 and
then generates the appropriate signals for USB.

You should contact Metrologic for information on the USB line protocol
and all specifications.

>       Endpoint Descriptor:
>         bLength                 7
>         bDescriptorType         5
>         bEndpointAddress     0x02  EP 2 OUT
>         bmAttributes            3
>         Transfer Type            Interrupt
>         Synch Type               none
>         wMaxPacketSize          8
>         bInterval              10
>       Endpoint Descriptor:
>         bLength                 7
>         bDescriptorType         5
>         bEndpointAddress     0x81  EP 1 IN
>         bmAttributes            3
>         Transfer Type            Interrupt
>         Synch Type               none
>         wMaxPacketSize          8
>         bInterval              10

I've never seen interrupt OUT transfers. Are these possible?

BTW: Since when is libusb supporting interrupt pipes? Would be
interesting for a project of mine too.

Bye
  Hansi

-- 
Johann Glaser   <Joh...@gm...>
   Vienna University of Technology
       Electrical Engineering 
____ http://www.johann-glaser.at/ ____