Consulter notre FAQ

Is there a first scan bit available in SoMachine or EcoStruxure Machine Expert?

Issue
How do I logically determine the first Task Cycle in a SoMachine or EcoStruxure Machine Expert PLC?

Product Line
SoMachine (Versions: v2.0, v3.1, v4.0, v4.1, v4.2, v4.3)
- PLCs: M238, M258, HMISCU
EcoStruxure Machine Expert (Versions: v1.1, v1.2.x, v2.0, v2.1)
- PLCs: HMISCU, M241, M251, M262

Environment
PLC programming software for Windows PC -> Logic Builder -> POU program

Resolution
The functions "IsFirstMastColdCycle" and "IsFirstMastCycle", is True during the first MAST task cycle after a start.

For example, with this small program in Structured Text:
(a and b are INT variables)

IF IsFirstMastColdCycle() THEN a := a + 1; END_IF IF IsFirstMastCycle() THEN b := b + 1; END_IF

Result:
The value of "a" will be 1 the first time that the PLC starts (Cold Start).
The value of "b" will increments each time that the PLC stops and starts (Warm Start).