Reference Manual

PMAC 2 Software Reference
PMAC I-Variable Specification 89
Ix34 Motor x PID Integration Mode
Range
0 .. 1
Units
none
Default
1
Remarks
Ix34 controls when the position-error integrator is turned on. If it is 1, position error
integration is is the input to the integrator that is turned off during a commanded move,
which means performed only when PMAC is not commanding a move (when desired
velocity is zero). If it is 0, position error integration is performed all the time.
If Ix34 is 1, it 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 Ix69 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
Ix34 to 1 so the dynamic behavior of the system may be observed without integrator
action. Ix34 may be changed on the fly at any time to create types of adaptive control.
See Also
PID Servo Filter (Closing the Servo Loop)
I-variables Ix30-Ix33, Ix35-Ix39, Ix63, Ix69
Tuning Instructions (PMAC Executive Program manual)
Ix35 Motor x PID Acceleration Feedforward Gain
Range
0 .. 8,388,607
Units
(Ix30*Ix08)/2
26
DAC bits/(counts/cycle
2
)
Default
0
Remarks
Ix35 adds an amount to the control output proportional to the desired acceleration for
Motor x. It is intended to reduce tracking error due to inertial lag.
If the servo update time is changed, Ix35 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 µsec to 220
µsec, Ix35 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.
See Also
PID Servo Filter (Closing the Servo Loop)
I-variables Ix30-Ix34, Ix36-Ix39
Tuning Instructions (PMAC Executive Program manual)
Ix36 Motor x PID Notch Filter Coefficient N1
Range
-2.0 .. +2.0
Units
none (actual z-transform coefficient)
Default
0
Remarks
Ix36, along with Ix37 – Ix39, is part of the notch filter for Motor x, whose purpose is to
damp out a resonant mode in the system. This parameter can be set according to
instructions in the Servo Loop Features section of the manual.
The notch filter parameters Ix36-Ix39 are 24-bit variables, with 1 sign bit, 1 integer bit,
and 22 fractional bits, providing a range of -2.0 to +2.0.