Cancel Method (PIAsynchStatus Object)


The Cancel method is used to terminate long running calls when complete results are no longer desired.



The Cancel method syntax has these parts:

Part Description
object An object expression that evaluates to a PIAsynchStatus object.


Responsiveness of the call depends on the granularity of the internal call placed to the server.  For example an internal call to retrieve message from the message log may fetch 1000 messages at a time.  The cancel can only occur between fetches.  There is a trade off between a fine granularity for canceling and overall performance.

Trappable Errors

In addition to generic errors (such as Out of Memory), the following errors may occur:

Error Description

Call has already completed.


Call is not yet in progress, or call is in the process of being canceled already.

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