Pulse Actions

A pulse action is a list of instructions which are executed only once at the activation of the step: P1 qualifier, or executed only once at deactivation of the step: P0 qualifier. Instructions are written using the Structured Text (ST) or Ladder Diagram (LD) syntax. This shows the results of a pulse action with the P1 qualifier:

Step Activity

Execution

Example

In this Sequential Function Chart (SFC) program, step S1 is assigned an ST action named EdgeInit having the P1 qualifier and S2 is assigned an ST action named EdgeCount having the P1 qualifier. The code for these actions is programmed in their respective level 2 window.