USING AND CONVERGENCE (CONV AND 2)
Convergence to AND is used to link a unique operating phase after simultaneous operating phases. This method of linking operating phases performs the inverse function to that of AND divergence .
Two simultaneous operating phases (steps 1 and 2 of B01) can be followed by a single operating phase which can only be initialised after the simultaneous end of the two previous phases. An SFC function called AND CONVERGENCE FROM 2 SFC BRANCHES (or CONV AND 2) is used to represent this operating mode. The function is wired to the two upstream step functions, each of which symbolises one of the simultaneous operating modes and to one downstream step which symbolises the single phase which is linked to the two previous operating phases.
If, at the same time:
Each of the tokens migrates from its respective step, crosses the transition with which it is associated and merges into a single token, which, when it falls into step B02, activates the next single operating phase.
If a single token is present in one of the upstream steps and the other step is empty (inactive), nothing will happen, even if the transition is controlled to ON. The step which contained the token remains active (digital step observation output ON) and the downstream step (B03) remains inactive.