what the difference between "Wait Until Next ms Multiple" and "wait" vi's ?

[pro111]

Hi all.

1) What the difference between "Wait Until Next ms Multiple" and  "wait"   vi's ?

2) If i put thos vi's inside state machine, for example, inside state number 3, when the program reach to this state, the delay will ganerate  

    before or after the execution of other component in this state  ?

thanks 🙂

[altenbach]

Both will start in parallel to all the other nodes in the same frame but they still have different finctionality. You cannot guarantee what starts first. The main differences show up if you have other slow tasks in other frames of the same state or the slow task starts before the wait.

Wait next ms multiple: This is only useful in a loop, because it tries to keep the same time frequency, irrespective of how long other nodes take. The first call might be way off.

Analogy: Do something always 10 minutes after the hour.

(If you start working on the hour, the first wait will only take 10 minutes, but then all further tasks will be spaced exactly one hour.)

Wait(ms) Wait a give amount of time before continuing.

Analogy: do something, take a 1 hour break, do something, take another 1 hour break, etc. The repetition rate will somewhat depend on the lenght it takes to do the other tasks.

[altenbach]

Here's a nice write-up by NI:

http://zone.ni.com/devzone/cda/tut/p/id/4120