4 display controllati tramite labview

[PJS]

I do not believe you can guarantee simultaneous transfer and update.  However it may be close enough to not matter.  You will have to try it.

you can write the low level USB interface yourself, but the manufacturer probably has a driver and API which should be able to be utilized by LabVIEW.  However without the display details, specifications, make and model... we can only guess at best.

[unisol]

ok, I know only that the controller has a USB connection and that the images or videos are sent via proprietary software. The display is QVGA RGB

[PJS]

you will need to contact the manufacturer to find the API for using their proprietary software in programming environments.  We really cannot provide any assistance here without knowing the manufacturer and model.  Even with this knowledge, unless we can read the documentation for the their software we really can't do much unless someone has used that equipment.

It is equivalent to saying I have a digital multimeter and need to interface with it.  No one can really help without knowing who made the multimeter and what model it is.