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FAQ (Frequently Asked Questions)
How do I access the process image with more than one thread?
This is not recommended. The control register for consistent reading and writing of
slave data can then be overwritten, so that, for example,the consistency of the
slave data currently being read by a thread would be jeopardized.
To avoid this, some form of interlock would be necessary so that only one thread
can access the process image at any one time. You could do this using
semaphores, mutexes etc. in Windows NT.
How can I access the process image with multiple programs?
This works fine as long all the programs involved release the pointer to the process
image again with the DP_release_pointer call. In real-time operation, we would
advise against this, since both calls take up time and you would need to implement
extra mechanisms to coordinate the programs.
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DP Base Programming Interface for CP 5613/CP 5614
C79000-G8976-C108-02
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