Will units not on the same sub net will they still appear on vCastReceiver list?

No, it’s cross sub net network limitation and please input screen PIN-code for casting connection.

I want to use one PC to connect 2 units of IFP7550 and the touch functions can be controlled by PC, is it possible?

Yes, it is possible. Please refer below connection image, then to use Windows to calibrate.

Can IFP7550 USB port share to external laptop?

No, IFP7550 USB port cannot share to external laptop, it only share to slot-in PC(VPC10 and VPC14).

How to change IFP7550 icon in Quick access button?

The icon in Quick access button(side tool bar) is fixed, user cannot change it.

What model can be installed to VB-STND-003?

VB-STND-003 supports ViewSonic display up to 75" .

What model can be installed to VB-STND-001?

VB-STND-001 supports ViewSonic display up to 86".

How long will IFP7550 turn off itself when no any operation in Embedded Player source?

IFP7550 won't turn off itself when it in Embedded Player source. You need to set Timer to schedule IFP7550 power on and off time.

I can’t get the date and time auto sync for IFP7550, what’s the server address?

The server information shown below. NTP server: 2.android.pool.ntp.org UDP port: 123

I connect an amplifier to IFP7550 Audio output, the volume of the amp has to be set to at least 80% to at least be loud enough. Is it normal?

The Audio output level is adjustable, it will be changed when you adjust volume by front button or remote controller. Please to turn the volume up.

I cannot use ViewBoard 2.1 save a file to UNC path, how can I do?

ViewBoard 2.1 does not support UNC path, so user cannot use ViewBoard 2.1  to save file to a UNC path,