Delta Tau 5xx-603869-xUxx - Manual (Page 39)

Brick Motion Controller Hardware Reference Manual
System Wiring 31
Ixx30: Motor xx Proportional Gain
To create a closed loop position response with a natural frequency of approximately 25 Hz and a damping
ratio of 1, use the following calculation:
) MHz ( PFMCLK * 08 Ixx
000 , 660
30 Ixx =
Example:
PFMCLK is set to default of 9.83 MHz, and Ixx08 is set to default of 96. Ixx30 = 660,000 / (96 * 9.83) =
700.
Ixx31 Motor x Derivative Gain
Derivative Gain is set to 0 because the motor system behaves like a velocity-loop servo drive. This
parameter sets the system damping which should be unnecessary.
Ixx32 Motor xx Velocity Feedforward Gain
Use the following equation to establish a value for Ixx32:
Ixx32 = 6660 * ServoFreq (kHz)
where ServoFreq (kHz) is the frequency of the servo interrupt as established by I7m00, I7m01, and
I7m02.
Example:
ServoFreq is set to default of 2.26 kHz (I7m00 = 6527, I7m01 = 0, I7m02 = 3). Ixx32 = 6660 * 2.26 =
15,050.
Note:
If Ixx30 were set differently from the above calculation, then Ixx32 would change
inversely. For instance, if Ixx30 were twice the above calculation, then Ixx32
would be half its calculation.
Ixx33 Motor xx Integral Gain
Typically, This I-variable should be set to 0. The digital electronic loop does not present offsets or
disturbances that need correction in the PMAC.
Ixx33 may be set to force zero steady-state errors, should they be present with electronic encoder
feedback.
Ixx34 Motor xx Integration Mode
The default value of 1 is sufficient for this, since usually Ixx33 is set to zero. When Ixx33 is set to 0, this
I-variable has no effect.
Ixx35 Motor xx Acceleration Feed-forward Gain
Start with this I-variable set to 0. Typically, this value does not need to be changed. However, Ixx35
might be adjusted to compensate for the small time delays created by the electronics when accelerating
the stepper. The effect of adjusting Ixx35 will be to reduce a slight following error during motor
acceleration.
Ixx36 - Ixx39 Motor xx Notch Filter Coefficients
These values should be set to their default value of 0. Since filter parameters adjust the way the gains
operate due to physical resonance of a system, there is no need to set these I-variables.