Schneider M221 Ladder Function

[Andrew EPS]

Hi Guys,
I'm converting a Zelio program (in FBD) to an M221 (Ladder) and having a brain issue.

I am monitoring two analog inputs. When both analogs are above a set value for a set time, I want to energise an output. In the Zelio, I used a Schmitt trigger so I had hysteresis (deadband), but am unsure how to achieve this in ladder in the M221.


Any help would be greatly appreciated.

 

[janner_10]

Just break it down into small chunks.

Monitor both inputs, 2x GRT than n °C starts a TON, when TON is done write output.