I would send a msg_get to the source in a twon_range and check the stepsize. If everything else is working I’d guess that the source is using 1000 as the stepsize and rounding the 100 you’re trying to set down.
Check the rc/cc for your calls to see if you’re failing for some reason and checking supportedCaps with querysupport will also occationally provide some insight.
One question, you call:
twainScanner.showNativeSourceInterface( source,false );
just before you set and get the values. Is the vendor Ui up when you get and set the values?
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