Register for module events inside a subVI

[bratdv]

I have a parent module that starts a group of child modules. I am trying to follow HSE guidelines https://dokuwiki.hampel-soft.com/kb/labview-frameworks/dqmh/starting-modules .

One thing that bothers me esthetically is the need to grow EHL vertically in order to accommodate large number of  event sources. Is it possible to place this node in a subVI? When done directly, it has a compilation error:

I understand that event registration ref num controls I used have private typedefs inside that prevent the usage outside owning library, but I can't figure out how to fix this.

Any solution?

Thanks,

Anton.

[ChrisFarmerWIS]

At Wired-in, we start our modules inside an EHL event with a for loop, and starting each module one at a time.  This will take longer than launching them all in parallel, but sometimes order is important (ie you want to have a database module or a error logging module running before starting modules that depend on those).  Anyway, the point is that the code doesn't suffer from the vertical growth issue.

[bratdv]

Christopher,

the vertical size of "Register for events" remains 10 levels in my case, right? If every event should be connected to the correct "level", how do you do this in a for loop? Wiring has to be different for each iteration... I just can't imagine it in my head. Can you please provide a bit more explanation or a quick screenshot?

Or do you mean you have 10 (in my case) EHL cases, one for each of the modules, and these events (cases) are called from a for loop within MHL?

Thank you!!

[ChrisFarmerWIS]

Yes, the register for events still is 10 levels, so you can't avoid that.

Not 10 separate EHL cases, just one but using a FOR loop:

This event case is called from a request in the MHL Initialize case.

[bratdv]

Thank you, Christopher.

I ended up doing a combination of HSE recommended scheme with your For Loop approach. MHL cycles through start module and sync VIs for all modules, in between sending a private request to EHL to register for events:

One more thing I want to do is to add handling "Module did init" event in MHL case (right after sync). This way when the MHL's for loop went through all modules, they are all started, initialized and ready.

Best,

Anton. 

[joerg.hampel]

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@bratdv wrote:

I ended up doing a combination of HSE recommended scheme with your For Loop approach. MHL cycles through start module and sync VIs for all modules, in between sending a private request to EHL to register for events:

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Just to follow up: The article on our Dokuwiki contains a "When to start" section which states the following:

• HSE modules with the need for automated sequential steps usually feature a State Machine

Meaning that if we need to start a number of modules, more often than not we will do that from a HSE State Machine module, going through each child module one by one to maintain control over what worked and what didn't.