This info is from the PolarFis programmer.
http://www.auto-polar.com/forum/showthread.php?1034-PolarFIS-(Advanced)-New-Update-v0-4-2-23-12-2013
the values used in DPF status;
0 - No DPF regeneration is necessary.
1 - Indicates the ongoing regeneration (with high exhaust temperatures). During this phase, the soot loading begins to degrade.
2 - Shows an active heating (exhaust temperatures are raised.
10 - Indicates that a DPF regeneration is requested.
Once a regeneration finishes, the value will be reset to 0.
Btw, There are FF20 and FF40. I'll look for their definitions.
My observations lead me to think the above is not correct.
This is what I see as correlation for the DPF status:
FF01 normal mode
FF10 DeNOX regen
FF02 DPF active regen
FF20 DeSOX regen (up to 20 minutes, right after FF02, but only once every 3-5 DPF regens)
FF40 adaptation/calibration/test cycle (during warm up infrequently)
FF80 different adaptation/test cycle (very infrequent)
(I saw the last two values after changing Exhaust Pressure Sensor (EPS) 2 and adapting EPS1)
http://www.natef.org/NATEF/media/NATEFMedia/VW%20Files/2-0-TDI-SSP.pdf
See page 71 and earlier for background on the exhaust treatment system cycles and processes
Note that DPF status on the PF03 is also reported by the engine controller as measuring block 104, field 1, which is labeled "0xFF02=done" (note that 0x indicates a hexidecimal value). VCDS can be used to view and log this value and see how it relates to other readings, including the various exhaust temps.
charts from some logging I did on the temps is here
http://www.myturbodiesel.com/wiki/dpf-obd-charts/
This is really a status message, included for reasons not published. We are all guessing as to the true intent (unless someone has a translation of the source code)
This is over an hour drive or so. Shorter spikes are the FF10 (DeNOX), and the longer one at the end is FF02 (DPF active regen)
The requested regens number is kind of a counter of the need for a regen. if everything is working, it increments once in a while, and when it gets to 5, a DPF regen is around the corner. depending on how long the active regen goes, it will decrease on the way down during the regen to 0 or 1. more if you stop before the regen is done.
one more note is that during an FF10, if you let off the go pedal, (fuel goes to 0) it will go back to FF01, and may come back up if you press the pedal again, calling for more power. this makes sense to me, as the DeNOX regen needs extra fuel. must be too hard for the EGR to go to no O2 in the intake, which would let the fuel be heated as required for the regen without adding power to the drivetrain. if I press on the pedal a bit later, it may come back to FF10.