Stop/Start are System Common messages, they are not a CC.
Sticking an FC (Stop) and an FA (Start) is a workaround to getting the OT to start a Pattern immediately instead of following the OT’s Pattern Behaviour settings. This is not something that can be done from the Pyramid alone and is done with a Translator. (well, it can be done manually, but you have to be very fast and the whole point of the exercise is to limit the interaction with one machine so that I still have a hand free to do ‘other things’)
Sticking an FC before and an FA after the PgmChg msg works, btw. I was using it, but still reconfiguring my rig between parallel sequencers for communication between them so it may be a moot point.
When you press [>] (Play) on a sequencer, it sends out the FA MIDI Message to tell other gear to start, if your sequencer is set and/or able to communicate that information. What happens on the receiving end is dependent on the settings on that device (case in point, I can set the OT to not pay attention to Start/Stop).
CC69 is listed on the MIDI Implementation Chart for the Pyramid to accept/control Pyramid Sequencers via MIDI messages.
Reading the manual is important, but at the very least, I’d recommend reviewing/understanding the MIDI Implementation Chart if you want to send control values between gear. Check on the bottom under PyraMiDi Messages and the examples:
I don’t know how ‘common knowledge’ it is. Just part of my personal workflow.
Note: several other people here with more knowledge than I use DT with Pyramid. If you run into issues controlling the DT from the Pyramid (if that’s your chosen data/work flow), I’m sure a fresh thread on the subject (if one doesn’t already exist) would give you MORE than enough specific application information.