[Article based on BioStarSDK_V188.8.131.52_20181004]
If you've tried searching Wiegand devices with the SDK sample Wiegand Control, you may have run into the error below.
[screenshot is of a altered version of Slave control where I added the Wiegand control code]
This occurs because if the Convert.ToUInt32 value is less than 0 an error occurs.
In that case change the code
UInt32 wiegandDeviceID = Convert.ToUInt32(Marshal.ReadInt32(wiegandDeviceObj, (int)idx * sizeof(UInt32)));
to below to resolve the issue
UInt32 wiegandDeviceID = (UInt32)(Marshal.ReadInt32(wiegandDeviceObj, (int)idx * sizeof(UInt32)));