Why are some blocks "not executed"?

Submitted by Joe on Tue, 06/01/2010 - 10:53
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I have noticed that when I right click on some block output pins I see "not executed". They only execute after attaching a display or plot block to the output. Why is that?

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This is an optimization feature.

Submitted by Anders89 on Tue, 06/01/2010 - 11:04.

In some sense, it boils down to the philosophical question: "If a tree falls in the forest, and no one is there to hear it, does it make a sound?". VisSim chooses to answer this question "no". This is a VisSim feature to optimize performance. If the block has no output, (a "signal consumer") it is always executed. If a block has one or more output pins, and none of them are used or ultimately connected to a signal consumer, then VisSim does not include the block in the execution set.
Some examples of signal consumers are: display, plot, histogram, PWM output, OPC write, CAN bus write, UDP packet write , export to file.