The DPS watcher should behave normally under a static fill of the IP.
If filling with hydrogen gas then the purge gas should be used on stages 1 and 2. If you don't, the foreline pressure will build up slowly and eventually impact beamline pressures.
Open the valve on the 6 pack and ensure regulator reads about 10 psig
Open the purge gas valves on US1 and DS1 - Channels 1 and 2 on Beckhoff controller "N".
Be sure to stop the purge gas and close the valves when finished.