[jan-jaap]

Since VIGRA is a 6U-Board, is it installed in the upper or lower 2/3 of Onyx 9U Card Cage?

You use a 6-to-9U VME adapter. A 6U card has the P1 and P2 connectors, a 9U VME card has P1, P2 and P3. See here: http://www.interfacebus.com/Design_VME_Card_size.html

Here's a 6U FDDI VME card in a 9U adapter:



So you end up connecting to the upper 2 connectors if I'm not mistaken