Reference Manual

Turbo PMAC/PMAC2 Software Reference
Turbo PMAC Global I-Variables 113
Ixx34 Motor xx PID Integration Mode
Range: 0 - 1
Units: none
Default: 1
Ixx34 controls when the position-error integrator is turned on. If it is 1, position error integration is
performed only when Motor xx is not commanding a move (when desired velocity is zero). If it is 0,
position error integration is performed all the time.
If Ixx34 is 1, it is the input to the integrator that is turned off during a commanded move, which means
the output control effort of the integrator is kept constant during this period (but is generally not zero).
This same action takes place whenever the total control output saturates at the Ixx69 value.
This parameter is usually set initially using the Tuning utility in the PMAC Executive Program. When
performing the feedforward tuning part of that utility, it is important to set Ixx34 to 1 so the dynamic
behavior of the system may be observed without integrator action. Ixx34 may be changed on the fly at
any time to create types of adaptive control.
Ixx34 is not used if Iyy00/50 for the motor has been set to 1 to enable the Extended Servo Algorithm
(ESA) for the motor.
Ixx35 Motor xx PID Acceleration Feedforward Gain
Range: -8,388,608 - 8,388,607
Units: (Ixx30*Ixx08)/2
26
16-bit output bits / (counts/servo update
2
)
Default: 0
Ixx35 adds an amount to the control output proportional to the desired acceleration for Motor xx. It is
intended to reduce tracking error due to inertial lag.
If the servo update time is changed, Ixx35 must be changed by the inverse square to keep the same effect.
For instance, if the servo update time is cut in half, from 440 sec to 220 sec, Ixx35 must be quadrupled
to keep the same effect.
This parameter is usually set initially using the Tuning utility in the PMAC Executive Program. It may be
changed on the fly at any time to create types of adaptive control.
Ixx35 is not used if Iyy00/50 for the motor has been set to 1 to enable the Extended Servo Algorithm
(ESA) for the motor.
Ixx36 Motor xx PID Notch Filter Coefficient N1
Range: -2.0 - 2.0
Units: none (unit-less z-transform coefficient)
Default: 0.0
Ixx36, along with Ixx37-Ixx39, is part of the second-order notch filter for Motor xx, whose main purpose
is to damp out a resonant mode in the motor/load dynamics. This filter can also be used as a low-pass
filter and a velocity-loop integrator. This parameter can be set according to instructions in the Servo
Loop Features section of the manual.
The notch filter parameters Ixx36-Ixx39 are 24-bit variables, with 1 sign bit, 1 integer bit, and 22
fractional bits, providing a range of -2.0 to +2.0.
The equation for the notch filter is:
2
z2D
1
z1D1
2
z2N
1
z1N1
)z(F









This parameter is usually set initially using the Tuning utility in the PMAC Executive Program. It may be
changed on the fly at any time to create types of adaptive control.