With the information about the veclink cables I was given a couple of binaries.
One of the binaries ("BerzerkArena") is fantastic prototype game made by Alex Herbert
I partly disassembled the program and commented it. I combined the disassembled serial communication routines with the example I had for VecLink V1. I guess by now it can also be seen as a well documented example on how to use veclink V2.
It can be found in the directory:
codelib/Snippets/Alex Herbert/VecLinkV2/vecLinkV2.asm
The program can be assembled and run in vide.
For more information look at the source to the example and possibly at the "Emulation: VecLink V1 + V2" section.
Let me remind you, that there is no way to "automatically" configure vide to run two vecx instances, you have to start two instances manually:
Manually meaning:
go to the main menu and start a vecx
select the veclink binary you would like to play
press start
select for port 0 the input device you would like to use
select for port 1 the veclink cable you would like to use, start with the "left" side (although it does not really matter which side is plugged in first)
repeat the above process for a second vecx instance,
for port 1 select the "other side" (right?) of the same veclink cable

VecLink example