Experimental Physics and
Industrial Control System

That brings an interesting question:
What are all those 'simulation' records (SIMM, SIOL) used for?

These fields are used to set up the ability to test database logic without the need to have hardware there to fail - or to test client based code such as quad centering or beam steering. You can use the link to have one record set the thing into simulation mode if all SIOL point to the same link field. There is also a SVAL field (or something close to that). This should all be explained in the record reference manual. If it isn't - someone should add it.

SIMM allows you to say that the simulation is offering up either a raw digital value that needs to go through conversion, an engineering units value - ignore the conversion part of the record - or no simulation.