
This is one of the many entries in the MIDI protocol I sent you the link to.
So to control the video fader from QLab you would:
Create a MIDI cue
Patch the MIDI cue to the roland
Send MIdi Control Change with 10 as the first data byte and a value between 0 and 127 as byte 2, which corresponds to far left to far right video fader positions.
The values are written in Hex (base 16) in the protocol but you need to enter them as decimal integers. The H in the manual just indicates, the number is hex which uses 0 to F for the decimal values 0 to 15, so 7F is 7x16+15=127
There are quite a lot of controls that just use these simple MIDI voice messages.
Some controls require sending MIDI system exclusive messages. This is slightly more complicated because you have to calculate checksums for the data.
I can’t really include a crash course, in SysEx, Hex and checksum calculation in a a forum reply, but it isn't that complicated to learn, all the info you need is easily searched on line, and all the required messages are listed in the MIDI protocol.
But start with the simple voice messages first, and then see if there are any functions you need to use System exclusive for.
Mic