Servo velocity ini settings refresher

I need a quick refresher on some ini settings:
From my previous notes, MAX_OUTPUT = 7.92 should be 95% of of OUTPUT MAX and MIN correct? I'm keeping FF1 at 1 and tuning via P and output scale. Now, should my MAX_VELOCITY = 8.333 be below the MAX_OUTPUT value to leave some headroom or is it in general the same value as OUTPUT_MIN/MAX limits? I'm capping the trajectory section MAX_LINEAR_VELOCITY = 7.92 at the 95%.
Let me know if that approach is correct.

[AXIS_X]
MAX_VELOCITY = 8.333
MAX_ACCELERATION = 18.0
MIN_LIMIT = -0.2
MAX_LIMIT = 60.0

[JOINT_0]

MAX_OUTPUT = 7.92
ENCODER_SCALE = 2542.3542
OUTPUT_SCALE = 12
OUTPUT_MIN_LIMIT = -8.333
OUTPUT_MAX_LIMIT = 8.333
MIN_LIMIT = -0.2
MAX_LIMIT = 60.0

More questions:
This machine has 1 axis that is slower than the others. My jog slider allows to go up to full speed of the faster axes which does not work for the slower one as it trips an expected following error. Is there a way to do this without tripping a following error?
(Have the jog slider be at max velocity, allow slower axis to be capped by it's max_velocity setting)

[TRAJ]
MAX_LINEAR_VELOCITY = 7.92

How are the different max velocities typically handled for each axis?
If one issues a rapid, which max velocity number is obeyed?
During feed, if values are higher than machine max setting, how is it handled?

[AXIS_Z]
MAX_VELOCITY = 5.0

I appreciate your input. Thanks.

I general I would never set the output limits smaller than the output scale.
this just throws away velocity range/headroom with no gain

You would typically set the per joint or axis velocity limit to about
80 to 90 % of the per joint/axis drive/motor limits so you have some control
headroom.

The MAX_LINEAR_VELOCITY is the overall limit (in any direction)
The axis/joint limits will be obeyed so if you have a slow axis/joint
the per axis limits should never be violated. For example if you had
MAX_LINEAR_VELOCITY set to 8 and each axis had a limit of 5
you could reach the MAX_LINEAR_VELOCITY limit moving in a XYZ
diagonal (so the velocity would be bounded to 8) but a diagonal in XY
for example would be bounded by the axis limits of 5 each (to ~7.07)

Thanks for the reply PCW.

I'm confusing myself with old notes. I'll have to-re tune.
My other config uses +/-10 for the output limits and a lower output scale. I don't recall how MAX_OUTPUT comes into play. Is that the 95% of the desired velocity? PNC config put a 0 or 10 there. I don't recall if it's only used for compensation? What number is correct?

MAX_OUTPUT = 0, 10, 8.33, 7.92 ???
ENCODER_SCALE = 2542.3542
OUTPUT_SCALE = 8.33
OUTPUT_MIN_LIMIT = -10.0
OUTPUT_MAX_LIMIT = 10.0

OUTPUT_SCALE = 8.33
OUTPUT_MIN_LIMIT = -8.33
OUTPUT_MAX_LIMIT = 8.33

OUTPUT_SCALE = 8.33
OUTPUT_MIN_LIMIT = -8.33
OUTPUT_MAX_LIMIT = 8.33

With that, I ended up at 12 for the output scale during tuning. I also had the max output set so, I should just remove max output and re-tune?

TIA

You can calculate the scale by determining the velocity at 10V and using that number for
OUTPUT_SCALE and the MIN/MAX limits. You can also tune FF1 as accurately as possible
then get the actual OUTPUT_SCALE value by dividing the current OUTPUT_SCALE by the
tuned FF1 value. (and then setting FF1 to 1.00)

You could also disable the MIN/MAX limits by setting them very wide when tuning, and then set
them to the tuned OUTPUT_SCALE value when done.

I'm still confused abut the MAX_OUTPUT number. Docs are not clear to me on that. Do I leave it out in my INI? Or what value should I use?

On this retrofit I know roughly what max velocity was for each axis however I don't know what the output voltage was at that velocity.
So working from scratch, I limited my max velocity to just below what I know the machine is capable of. If I go above that, I can see my f error plot spike. If my output scale is higher than my limit, what does that suggest?

Another question I have is in regard of wiring the analog connection. I'm connected to old Fenner drives, (bipolar? I'll have to double check the manual, it didn't call out a specific ground or +) original control reversed connections on 2 drives which I copied and works correctly with motion. Just wanted to confirm that that is not an issue with the 7i77 and the old Fenners. If it is, I'll reverse it.
7I77 AOUT and GND wired to drives REF+ and REF- pin
and 2 reversed
7I77 AOUT and GND wired to drives REF- and REF+ pin ( bipolar ? pins)

MAX_OUTPUT sets the PID maximum output
I think I would leave it at 0 (unbounded) while tuning
you could also set it to the same value as OUTPUT_SCALE

OUTPUT_SCALE will always be somewhat higher than than the maximum
usable velocity because the control loop needs some headroom to operate
Say you are moving at OUTPUT_SCALE velocity (10V out) and the load increases
resulting in a tiny slowdown (because the drives velocity loop gain is not infinite)
the following error will increase because the PID output is already maxed out.

If the drives have differential inputs (AIN+ and AIN-) you can swap them to change the direction
beware that you cannot do this with single ended drives (AIN and ACOMMON)

PCW, thank you for your time. I appreciate your knowledge and help.

I'm having difficulty tuning the slaved axes. I'm posting my hal and ini in my other post as not to cross post.

velocity tuning YY2 gantry