CARLO GAVAZZI EM24 IS-R2-O2 Serie Mode D'emploi page 18

Essential information
Down alarm (on Al < off Al)
The alarm activates when the monitored variable drops below the on Al value for a time equal to the activation delay (t del) and deactivates
when it exceeds off Al.
18 EM24 IS - Instruction manual | CARLO GAVAZZI Controls SpA