When is Air Suspension Tank is used?

[brainhouston]

For tech gurus, as title says, i couldn't find any info...
When i choose to lift the car it turns on compressor
Also when u get an error "Compressor disabled" it says "car won't raise"
So why then we have air tank n when does it get used?
I saw in Service docs that u need to fill it to something like 200psi?...
Is that only manual? will compressor pump up the tank?
Anyone understands how the whole system suppose to work?

 

[brainhouston]

i still don't know how the complete system works but more info after driving more...

Compressor does seem to fill up reservoir, when exactly it runs n with what thresholds, i don't know.
Service docs say u need to fill it with N2 to 20 bar so it can go that high for sure.

When i select to raise suspension, compressor is quiet so its definitely using air from reservoir.