Is there any limit imposed by TUV on scan time? We have a SIL-3 certified system that can go up to 450mS scan time. However, project specification restricts it up to 300mS.

I would like to know whether any guidlines are available from TUV for SIL 3 certified systems.

 

Yes TUV requirement is 300ms for process and 500ms for fire and gas.

I dont think you will need more scantime for your RUNG. Normally process RUNG are shorter compared to F&G.

more information http://www.intro4u2u.com/category/technology/ipf/