Parameter Passing and using the TGDA |
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The usage of a function parameter determines whether any changes to its value are written back to the TGDA on function exit. Function parameters mapped as TGDEs always have ‘Both’ usage.
The usage of a Task parameter determines whether the value of a particular Task parameter is returned to the caller on Task exit.
Data defined with ‘Global’ usage is never passed in or out of a Task, but can be read and written by all member functions. This provides a named global data space within a given execution of a particular Task that can replace COMM variables.
Since tasks have no files and no executables other than functions, there is no concept of scratch or file data in a Task parameter area.
While you can map an entire array from the TGDA into a function parameter, you cannot map an individual array element (the element being either in the TGDA or being a function parameter). You cannot map an array element to a scalar (non-array element).
Topic ID: 540104