7i33 servo loop tuning error

Hi. I am trying to tune a servo loop using a 7i43, a 7i33 and a copley junus servo amplifier. The motor is a electrocraft e243. I have already tune the torque and velocity loop with the amplifier using the copley tuning program (CME2). The motor max speed is 5000 rpm.
I have tuned the amplifier so that 10v analog input is 4200 rpm (70 rps). I haven't link the motor to anything yet. So I have changed the scale to 1 turn = 1 mm so that the top speed is 4200 mm/min or 70 mm/second for clarity purpose. The encoder as 2500 input/rev. When I tune the drive at low speed I manage to have a low error or at least I can see that the error gets smaller when I tune the drive using halscope and the calibration tool. However I have some issues at higher speed where I have a big error. It seems to be a change when I crossed the 600 rpm mark. The error gets bigger, the faster I go. I have the same error bump with a P (PID) value of 20 or 150 so I don't think it come from PID values. Maybe the rate is to high for the 7I43. Does someone has an idea why I have this error?
I have attached the INI file and two screenshots. One is the velocity and error at 500 rpm and the other is the velocity and error at 600 rpm.
Thank you.

Try setting your OUTPUT_SCALE = 10 instead of 70.

When you set that to 70 it is like saying the maximum speed (70rps) would take 70 volts from your analog output to your amp, but the max output is capped at 10v. At F600 you run out of head room (your 600rpm or 10rps) and your max output hence the large growing following error.

Thank you for your answer. You are right. It works now. I thought that OUTPUT_SCALE was the 10v velocity in mm/s.
I guess the 10v velocity is MAX_VELOCITY.
Do you now what STEPGEN_MAXVEL is?
Thank you.

STEPGEN_MAXVEL and STEPGEN_MAXACCEL are the maximum velocity and acceleration settings for a step generator (step motor, or step/dir servo control). They don't really apply to an analog servo control, I don't know why they'd even be there. You can probably safely comment them out or remove them. Often they need to be set a little higher than the actual max velocity and acceleration settings for the joint, to accommodate backlash compensation, and some other things.

ok. I think it's in the INI file because I have use a firmware with 4 pwm and 4step although I haven't define any axe as step dir.

Thank you.

Be aware that a bare motor is often very hard to tune, and that the optimal tune for the bare motor will be very non-optimal once the motor is moving the machine.