Hmmm... D/A Trim is Analog Trim. Perhaps you mean D/A Trim vs. Sensor Trim. According to manual...
Analog Output Trim: Adjusts the transmitter's analog characterization curve to match the plant standard of the control loop.
Sensor Trim: Adjusts the position of the factory sensor characterization curve due to a change in the sensor characteristics over time or a change in test equipment.
Suggest you refer to the product reference manual (not the quick installation guide version [QIG]) for more detail.