Vinculum attach and de-attach problem for cdc device

[Selva]

I am using Vinculum 32 pin IC for my application  . I am using 5 cdc device which differs only in PID .
I have connected this 5 cdc device & vinculum through hub .
I have taken  CDC Modem sample code and working on it ,
we are facing few problem In attaching & de-attaching the CDC device . while switching from one device
to another ,  Its working properly with that  Vinculum reset function ( vos_reset_vnc2 ) . but we are
trying to do  without reset function .

I want to do proper attach and detach between usb host  & cdc device while switching .
kindly help me to solve this issue .

[Jan Axelson]

I don't have any specific recommendations, but a protocol analyzer will show what is happening on the bus and might offer a clue. Otherwise use whatever debugging tools you have to find out how the host is responding when you detach a device and attach another.

[Selva]

thanks for your reply..
I have some doubts ..
Is it necessary to do re-enumeration to switch from one cdc device to other .
or is it enough if we detach a driver & attach with other cdc device .

[Jan Axelson]

Detaching one device and attaching another requires enumerating the new device.