Some background first...Diesel Particulate filters (DPF) or 'traps' do just that, they catch bits of soot in the exhaust. As with any filter they have to be emptied regularly to maintain performance. For a DPF this process is called 'regeneration' – the collected soot is burnt off at high temperature to leave only a tiny ash residue.
If a regeneration is needed, you'll start to see temperature lights and the DPF indicator lights on your dash. The regeneration can sometimes be accomplished by driving at a higher rpm for 20 mins to burn the soot.
With that being said, a regen switch is used when you require a parked regeneration. There is a process outlined in the owners manual (in mine it's page 4.2). Takes between 20-50 minutes and will burn off excess soot. Basically, there are sensors in the exhaust and once there is so much soot it needs to be burned off.
In my case I noticed a temperature light, followed by the DPF light and shortly after that check engine light. Started loosing all power to the coach. My 2011 390 bh doesn't have a switch and it requires a cummins qualified tech to you their insight software to hook into your diagnostics to initiate a parked regeneration.
Above are my findings from the dilemma so far today. Hope this helps people in the future. I plan to stop by freight liner or cummins and ask to have a regen switch installed. Still sitting on the side of the road after 4 hours waiting on tech. Could always be worse though. Should be a ~1 hr process of we had a switch.
Just my two cents...