Experimental Physics and
Industrial Control System

Hi Tomas,

how to explain this? Why does Input_1 run twice at 10 Hz?

The original intention was to show an example where two records with SCAN=.1 second (i.e. Output_1 and Calculation_2) would both ask for the Input_1 record to process using the PP (Process Passive) mechanism that record links provide, thus Input_1 would be triggered twice in every 10Hz cycle.

However there is a mistake in the diagram; the Output_1.DOL link needs to be marked with the PP flag but as drawn it is flagged with NPP instead, so as drawn the Output_1 record will never actually  request the Calculation_1 record to be processed at all, thus the Input_1 record will only process at 10Hz.

Was that what you were asking?

- Andrew

-- 
Complexity is free, it's Simplicity that takes work.