On Tue, Jun 3, 2008 at 5:31 PM, Prologix <[EMAIL PROTECTED]> wrote: > Short version: > Connect USB cable before connecting GPIB, and leave USB connected and > powered.
That isn't realistic for my setup. > Long version: > On startup, if one of the MCU I/O lines is pulled low, the controller will > enter firmware update mode. As it happens, this I/O line is also one of the > GPIB bus signals. Some instruments seem to have stronger pull-down on the > bus lines than others. The controller may enter firmware update mode, if the > USB cable is plugged in while the controller is connected to such an > instrument. Since the pull-down is passive, this behavior could happen even > if the instrument is powered down when connecting USB. Honestly, this sounds like a serious design flaw to me. I have 5 GPIB instruments, and 3 of them cause this behavior. If 3 pieces of test equipment from 3 different manufacturers cause this behavior, it must be pretty common. Matt _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
