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Important: This document is part of the Legacy section of the ADC Reference Library. This information should not be used for new development.

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USBGetNextDeviceByClass Requires deviceRef

Q When I make the USBGetNextDeviceByClass call, error -43 (file not found) error is returned. My device is attached, and is displayed by USB Prober. The call used to work, but no longer. Why?

A If you make the USBGetNextDeviceByClass call, you must set the input deviceRef parameter to a valid device ref or to the predefined constant kNoDeviceRef. If the deviceRef parameter is a different value, then error -43 results. If you set the input deviceRef value to a valid deviceRef, then USBGetNextDeviceByClass returns the next device that is found in the "USB device list", which matches the specified criteria. The key point here is that the input deviceRef value must be valid or -1. Note that error -43 might still be returned, if there are no more devices in the device list.

[Sep 28 1998]



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