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This function is used in Python Scripting.


Performs a write to a tag, synchronously. This means that you know at the end of this function whether or not the write succeeded or not. A write that fails or times out will throw an error. However, this function cannot be called from the event dispatch thread, which means that it cannot be called directly from a GUI event like a button press, without wrapping it in a system.util.invokeAsynchronous. You can call this from project event scripts like timer scripts.

Client Permission Restrictions

This scripting function has no Client Permission restrictions.


system.tag.writeSynchronous(tagPath, value [, timeout])

  • Parameters
    • String tagPath - The path of the tag to write to.
    • Object value - The value to write.
    • int timeout - How long to wait in milliseconds before timing out pending writes. The default is 45000 milliseconds. [optional]
  • Returns
    • Nothing
  • Scope
    • All

Code Examples

Example #1
# This code would write the value 1 to a tag. It will continue immediately on success or failure, or wait up to 38 seconds if the write is pending.

system.tag.writeSynchronous("Tags/T5", 1, 38000)
# This line will not be reached until the tag write succeeds, fails, or has been
# pending for at least 38 seconds.