What is the difference between simulation and loop check in plant startups?

Simulation is the option which is available on SMART Instruments to trigger(to a specific value) the process variable,loop current,other additional parameter for testing and checking purposes which wasn’t available physically as much on live process…

Loop check is the procedure or practice to ensure and check the loop is perfect,signal dropping or not,continuity,Linearity between output signal and controller indication on faceplate…etc