First, note that it's important that if you open a TWAIN Device, change a setting, then close it, the setting does not "stick". You need to ensure in your code that you are following the pattern:
if(myDevice.TryOpen())
{
myDevice.SomeProperty = someValue;
myDevice.SomeOtherProperty = someOtherValue;
// etc...
myDevice.Acquire();
} else {
// notify user that device could not open
// often due to scanner not being connected or not powered up
}
This can also when the driver isn't allowing DotTwain to change the property value.
The Twain specification contains many properties. Most devices only implement a small fraction of these. It's also common for a driver to have a property in their own user interface that they don't allow third party components to change.
You can attempt to determine what features your scanner actually supports by downloading, installing, and running TWISTER to generate a report on your device.
TWISTER is a free to use utility from EZTwain (which has been part of Atalasoft since 2011)
Original Article:
Q10072 - INFO: When I set a property value in DotTwain it doesn't change. Why?