> From: Richard Ryniker <ryniker at alum.mit.edu> > Date: Thu, 26 Apr 2012 08:02:03 -0400 > > >Now it is guess work why the device is temporarily unavailable when > >trying to reset it, but replies just fine to the status query to comes > >immediately after. > > Timing issue? Perhaps the two bytes written to the device start some > action that has not completed before the read request is tried, > therefore the "Resource temporarily unavailable" status. If the read > operation is retried, it might succeed.
Would this explain why the backend works the first time it is called from within a shell, and then stops working until a new shell is opened (as I described earlier)? > If there are other devices on the same bus, activity that involves one of > those devices may be an issue The EPSON is the only device on the USB bus. -- Giorgio ------------------------------------------------------------------------ Dr. Giorgio F. SIGNORINI, PhD Dipartimento di Chimica tel: +39-055-457-3085 Universita` di Firenze via della Lastruccia, 3 email: giorgio.signorini "at" unifi.it I-50019 Sesto F. (Firenze) Italy http://www.chim.unifi.it/~signo My PGP key: http://srv.chim.unifi.it/~signo/signo.asc ------------------------------------------------------------------------