Input Parameters

Unless otherwise specified in the function block's description, the input parameters are read with the rising edge A rising edge is the transition of a digital signal from low to high. It is also called positive edge of the Execute input.

The input parameters are:

• Function Blocks with Execute:
  
  • These FBs initiate execution on the rising edge of Execute.
  • Execution continues until completion independent of the Execute value (or values) following initiation.
  • Once execution is complete, the function block can be rearmed or reengaged by introducing another rising edge of Execute.
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  • Dual-Core limitation: Consecutive calls to the function block with repeating Execute values in the same cycle return an error code 76.
• Function Blocks with Enable.

  • These FBs continuously execute every PLC "Programmable Logic Controller" A Programmable Logic Controller, PLC, or Programmable Controller is a digital computer used for automation of industrial processes, such as control of machinery on factory assembly lines. Used to synchronize the flow of inputs from (physical) sensors and events with the flow of outputs to actuators and events cycle, as long as the Enable remains high.

• Function with En

  • This is similar to ENABLE on Function A function calculates a result according to the current value of its inputs. A function has no internal data and is not linked to declared instances. blocks.
    Functions are expected to complete in one cycle.
    See Differences between Functions and Function Blocks for more information.

See PLCopen Function / Function Blocks Input Parameters for the list of input parameters and descriptions for PLCopen Function/Function Blocks.