datediff problems

Good morning,

I wish to return a time (duration) in seconds from a certain element.

As soon as I get the label "Ordre fermeture vanne de garde" which is a closing order for a valve, i want to get the duration till i reach "Vanne de garde fermée" which indicates, thanks to a sensor, that the valve is closed. And i have to pay attention to which valve orders is, for this i got a column name "EGF".

This is how some dummies data looks like. I start a duration from a "Présente" (present) statement closing order, and finish to the first "Présente" statement closed valve. As i said before, i only return a time from same EGF.

Here you can download some datas : download link 

(password is : datediff)

I've tried some method, the more close one is this one :

Durée(secondes) = IF('test_vdg'[Description de l'évenement] = "Vanne de garde fermée";
        DATEDIFF(
            CALCULATE(
                MAX('test_vdg'[Date et heure]); 
                FILTER(
                    ALLEXCEPT(
                        'test_vdg'; 
                        'test_vdg'[EGF]); 
                        'test_vdg'[Description de l'évenement] < EARLIER('test_vdg'[Description de l'évenement]))); 
            'test_vdg'[Description de l'évenement]; SECOND); 0)

But it only return the duration from the previous label and it's not what i'm looking for.

If you need few more explainations, i'm here.