It depends what you mean by needing to convert it to an unsigned int. If you’re reading a value in from an Adam 6017 I assume it’s a 16-bit integer. A signed 16-bit integer will have a range of −32,768 to 32,767. An unsigned 16-bit integer will have a range of 0 to 65,535. To change from signed to unsigned you would simply add 32,768 to the number.
To do this in Ignition, read your input in to a SQLTag (say tag1), then create an Expression SQLTag and make its expression something like {[~]tag1}+32768This does mean you need 2 SQLTags for each input, but they’re free 
and if you’re creative with SQLTag names and folders it should still be clear what you’re doing.
Let us know if this is not what you are meaning.