Diameter Offset is an integer value that tells the post processor the number of the controller register in which the diameter offset value will be stored. For many controllers this is the "D" number.
The Diameter Offset value is the difference between the actual tool diameter and the programmed tool diameter. The actual tool diameter is determined by operator measurement. The programmed tool diameter is the Tool Diameter value that is displayed on the Tool Information tab. The difference between these two values is entered into the controller by the operator and stored in the register identified by the Diameter Offset number. This number is not a diameter measurement.