Start Scene on Boot

[m-joy 3]

Hi,

i am using HC2. How can i start a scene once on boot?

I want to initialize a global variable. I think after an upgrade process, the varible was wrong initialized.

By the way... what is the default value for initialisation of an variable?

[Sankotronic 2,370]

For scene to start at boot or after saving you need to add %% autostart to scene header like this:

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I don't understand your next question about default initialization of global variable, you must be more specific what it is about, but to set value to global variable you use following command:

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[m-joy 3]

Hi. Thank you! 

So what is %%events 

Used for? 

 

I had the feeling that my global variables values reset after System Update. But i xm not sure. So i wonder what values tgey get if they are resetted

[Sankotronic 2,370]

Global variables in general keep their values after system reset with few exceptions. There are two types of global variables on Fibaro system:

 

1) Predefined global variables and they usually have several predefined values (string type).

    They can also contain only one value in which is then stored table type value and they

    keep same value after rebooting the system

2) global variables are supposed to keep numerical values but they actually store numeric

    and string values as strings and as such stored values will stay same after system is

    rebooted. But if you store table type value in this type of global variable it will be

    destroyed after rebooting or even pressing save button on variable panel.

 

So, if you are not using any table type values stored in global variables then you should not worry about global variables because they will keep their stored value after system reboot including shutdown.

 

Regarding %% events it is used to trigger scene by centralSceneEvent generated by some devices like Fibaro swipe, if there is more than that I don't know.

[tnesheim 8]

Hi @

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Is your point 2) also true then the HC2 crashes and reboots?

[Sankotronic 2,370]

13 hours ago, tnesheim said:

Hi @

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Is your point 2) also true then the HC2 crashes and reboots?

 

Hi @tnesheim,

 

My HC2 crashed only three times, once on 4.120, once on 4.130 and recently on 4.140. In all three occasions I haven't noticed any problems with global variables, but that is not enough to be the rule. I believe that it is still possible that some global variable get corrupted by the system when it freezes or crashes.

 

Rebooting should not affect any global variables and they should keep their values stored intact. But still, if reboot happens in same time when some global variable should change value according to the schedule, then it is possible that change will not occur and after reboot it will have then wrong (old) value. This is definitely problem for block scenes with timers since they are very strict with time set, while with LUA it only depends on code how is written.

 

Just for example, this code in LUA changes global variable value only at specific time:

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So if reboot happens at just before 19:00 or 07:00 then global variable Darkness value will not change as expected. To avoid such problems it is better to change above code to be more flexible:

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This other example will still set global variable to proper value no matter when HC was rebooted!

 

Hope this shed some light on this matter.

 

Enjoy coding  

[tnesheim 8]

Hi!

Thanks for thorough answer! I realize that I also should have explained the background of my question. I´m about to implement a more advanced heat control in my home. I have about 8 heating devices(floors, heat pump, ventilation) and first step is to make individual setpoints for all units on normal and eco-mode. These setpoints need to be tuned to get right (I can probably guess quite right, but fine tuning is most likely  required). The setpoints will be stored in global variables. (tables is erased at reboot).

 

But what happens at a crash is my consern. Since I do not know to mechanisms storing global variables when rebooting where might be an internal function in HC2 that in the shutdown sequence stores the values to a non-volatile storage, and retrieves them at reboot.. If so, values at sudden crash are not stored and I will loose my fine tuned setpoints. Or, the global variable might be store in eg a flash and stored for every change.

Edited November 8, 2017 by tnesheim
typos