I don’t know the specifics for the mistic PIDs.
If you set the I term to 0, then the I term will have no affect on the output, same with the D term.
You may be confused on the terminology. On a PID loop, the I term is commonly called the “reset”. The term itself isn’t reset, but the output of the PID is adjusted to remove the offset error.
The difference between the velocity and the ISA algorithm is that the velocity algorithm calculates how much to change the output while the ISA calculates the output itself. Mathematically they are the same, functionally they have different characteristics. I like the velocity algorithm for the fact that I can manually change the output and the algorithm will take over from there. Downside to the velocity algorithm on Opto equipment is that the feed forward isn’t really usable.
The user guide says that the velocity algorithm is inherently “anit-wind up”. This is true in one way, and false in the way that matters (see below). The statement implies that the other algorithms have some sort of wind up issue, but they don’t, as they have wind up protection programmed into them (the I term will no longer “sum” when the output reaches saturation). There are very few controllers that omit wind up protection (I’m looking at you Honeywell).
However, the PID will still have wind up issues if your output range is large while your actual device control range is small. For example, if you have a temperature control valve that is oversized and has a control range between 0% and 30%, and for some reason you lose flow - the PID will happily increase the output until the control valve reaches 100%. When flow starts up again, you will have excessive overshoot while the output “unwinds” back down below 30%. This can happen no matter which control algorithm you choose (velocity is not immune to this).