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IoT Dev
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We are the manufacturer of a medical device which contains a Windows computer that talks to an embedded microcontroller via USB using the simple WinUSB interface.
Under the original Windows 7 (WES7 SP1), the communication worked fine. A custom GUI application takes control under the embedded shell when Windows starts.
Under Windows 10 IoT Enterprise, we see errors where the WinUSB pipes seem to fail about 40% of the time when the system starts up. If we reload the WES7 OS image back on the very same instrument, we don't see this failure rate.
The application does a DllImport of WinUSB.dll, and when it fails under W10, the errors trace to exceptions on reading or writing marshalled from the WinUSB library, e.g.:
UsbPortException: ErrorCode: 31: A device attached to the system is not functioning
It seems that the named pipes are no longer available to use.
If the system starts up without errors, it will continue to work indefinitely.
We've checked Windows device manager settings to verify that the USB related power management settings are disabled (power management - don't turn off power to this device. We also have set a custom high performance power plan.
I don't see any required Services marked for Delayed Start.
Any ideas on what might be different in W10 or W10's WinUSB?
Continue reading...
Under the original Windows 7 (WES7 SP1), the communication worked fine. A custom GUI application takes control under the embedded shell when Windows starts.
Under Windows 10 IoT Enterprise, we see errors where the WinUSB pipes seem to fail about 40% of the time when the system starts up. If we reload the WES7 OS image back on the very same instrument, we don't see this failure rate.
The application does a DllImport of WinUSB.dll, and when it fails under W10, the errors trace to exceptions on reading or writing marshalled from the WinUSB library, e.g.:
UsbPortException: ErrorCode: 31: A device attached to the system is not functioning
It seems that the named pipes are no longer available to use.
If the system starts up without errors, it will continue to work indefinitely.
We've checked Windows device manager settings to verify that the USB related power management settings are disabled (power management - don't turn off power to this device. We also have set a custom high performance power plan.
I don't see any required Services marked for Delayed Start.
Any ideas on what might be different in W10 or W10's WinUSB?
Continue reading...