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• Why the Command Input is Edge Sensitive

Why the Command Input is Edge Sensitive

Why the command input is edge sensitive

The Execute input always triggers the function with its rising edge. New input values may be commanded during execution of a previous command because the inputs are only read once. The 'Done' output can be used to trigger the next sequence required for the operation. The example given below is intended to explain the behavior of the function block execution.

The figure illustrates a sequence of three Function Blocks, 'First', 'Second' and 'Third', controlling the same axis. These three function blocks could be absolute or relative move commands. When “First" has completed, the output "First.Done" triggers "Second.Execute". The output "Second.Done" AND "In13" trigger "Third.Execute".