Bi-directional Edge (BDE) Trigger function block

The Bi-directional Edge Trigger (BDE) function block generates a True (1) discrete pulse output when the discrete input makes a positive (False-to-True) or a negative (True-to-False) transition since the last execution of the block. If there has been no transition, the discrete output of the block is False (0).

The Bi-directional Edge Trigger function block supports signal status propagation. There are no modes or alarm detection in the block.

Figure: Bi-directional Trigger function block

IN_D is the discrete input signal and status.

OUT_D is the discrete output signal and status.

The following figure shows the internal components of the Bi-directional Edge Trigger function block:

Figure: Bi-directional Edge Trigger  function block schematic diagram