Starting events at specific times of the day?

[grahamwebb]

Hi All, 

I would like to trigger events at specific times of the day, and would like suggestions on how the attached vi can be improved.   

The events will drive a state machine, as per this example by FuManWho: 

https://forums.ni.com/t5/Example-Programs/UI-Producer-Loop-with-State-Machine-Consumer-Loop-Using-La...

The vi works (as long as the consumer is slower than the producer), but I'm sure there is a better way of doing this! Custom events? QMH? 

Many thanks

Graham 

[GerdW · Accepted solution]

Hi graham,

just a suggestion:

You could put those FOR loops into the timeout event of your event structure…

[grahamwebb]

Oh I like that. Thanks. 

I did have them in the timeout at one stage but moved them around to get over a different problem - my event queue was filling up (to 99 events) in the time the 60 seconds the test condition was true. Limiting the queue size and adding delays worked but I didn't like stalling the consumer to get around that. 

[GerdW]

Hi Graham,

my event queue was filling up (to 99 events) in the time the 60 seconds the test condition was true.

You surely want to generate just one event when the conditions switches to TRUE!

So you need to include a comparison to check for changed conditions…

[grahamwebb]

Yes (at least I think so!). The event would be something like play mp3 file, switch light on, boil kettle etc. Single discrete events that begin at that time. 

[crossrulz]

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@grahamwebb wrote:

I did have them in the timeout at one stage but moved them around to get over a different problem - my event queue was filling up (to 99 events) in the time the 60 seconds the test condition was true. Limiting the queue size and adding delays worked but I didn't like stalling the consumer to get around that. 

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What you should do is add a shift register to hold the current comparisons.  Then you can do a if(current Value == TRUE AND previous value == FALSE) {do action}.

[Mark_Yedinak]

Do you really need to check for a timeout every 10 ms? That seems extremely fast for the types of events you are triggering.

[JÞB]

Since I can't open the VI (Installing 2017 now) and it is in 2017

Why not use "Value Changed.vim" on the Time Date record.(Day, Hour, Month, Minute) element as appropriate?

Hint: for bonus points you can even add a "Quotient & Remainder" to a counter that increments every (Whatever)

Anyone up to Whip in a simple example firing a "User Event" every n Seconds? (Wire control "n" to the divisor of Q&R test R=0, if so generate "User Event"

🙂 Bonus points if the user event data type contains a date-time record

[Ben]

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@GerdW wrote:

Hi graham,

just a suggestion:

You could put those FOR loops into the timeout event of your event structure…

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Also be aware of that issue with DST and the witching hour of 2:00 AM. One day of the year there are two hours that are "2:00 AM" and another day where there is NO "2:00 AM". As long as the trigger times are not in that window, just ignore me.

Ben

[JÞB]

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@Ben wrote:

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@GerdW wrote:

Hi graham,

just a suggestion:

You could put those FOR loops into the timeout event of your event structure…

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Also be aware of that issue with DST and the witching hour of 2:00 AM. One day of the year there are two hours that are "2:00 AM" and another day where there is NO "2:00 AM". As long as the trigger times are not in that window, just ignore me.

Ben

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Cast "To UTC" and ingore Ben this time.   😮