USING OR DIVERGENCE TOWARD 2 SFC BRANCHES (DIV OR 2)

Divergence to OR is used to link one or two operating phases after an operating phase. Two possible phases are available for selection. This method of linking operating phases performs the inverse function to that of OR convergence (CONV-OR 2).

An operating phase B01 can be followed by two operating phases which form a non-exclusive alternative: Operating phase B02 or B03, or both, are activated at the end of operating phase B01. An SFC function called OR DIVERGENCE TOWARD 2 SFC BRANCHES (or DIV OR 2) is used to represent this operating mode. The function is wired to two step functions, each of which symbolises one of the operating phases which can be selected (B02 and/or B03).

If the status token is present in the step (operating phase B01), the selection is made by forcing to ON one or/and both control inputs of each transition of B01 which are connected downstream of steps B02 and B03 respectively. This will bring operating phase B01 to an end and the token will migrate from step B01, crossing the closed transition(s) (the control input of which will be ON), towards the step to which it is connected.

First example: One of the two selection transitions is active.

Second example: Both transitions pass at the same time

Third example: If the programmer wants to make the choice between the next two operating phases exclusive, one of the two transitions must be controlled by an AND which combines the command of the first transition with the inverse of the command of the second transition.

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