Delta Tau GEO BRICK LV Reference Manual
Turbo PMAC/PMAC2 Software Reference
Turbo PMAC Global I-Variables
124
Ixx61 Motor xx Current-Loop Integral Gain
Range:
0.0 - 1.0 (24-bit resolution)
Units:
Output = 8 * Ixx61 * Sum [i=0 to n] (I
cmd
[i]-I
act
[i])
Default:
0
Ixx61 is the integral gain term of the digital current loops, multiplying the difference between the
commanded and actual current levels and adding the result into a running integrator that adds into the
command output. It is only used if Ixx82>0 to activate digital current loop execution.
commanded and actual current levels and adding the result into a running integrator that adds into the
command output. It is only used if Ixx82>0 to activate digital current loop execution.
Ixx61 can be used with either Ixx62 forward-path proportional gain, or Ixx76 back-path proportional gain.
If used with Ixx62, the value can be quite low, because Ixx62 provides the quick response, and Ixx61 just
needs to correct for biases. If used with Ixx76, Ixx61 is the only gain that responds directly to command
changes, and it must be significantly higher to respond quickly.
If used with Ixx62, the value can be quite low, because Ixx62 provides the quick response, and Ixx61 just
needs to correct for biases. If used with Ixx76, Ixx61 is the only gain that responds directly to command
changes, and it must be significantly higher to respond quickly.
Ixx61 is typically set using the current loop auto-tuner or interactive tuner in the Turbo PMAC Executive
or Setup program. Typical values of Ixx61 are near 0.02.
or Setup program. Typical values of Ixx61 are near 0.02.
Digital current loop closure on the Turbo PMAC requires a set of three consecutive command output
registers. Generally, this requires writing to either a PMAC2-style Servo IC or a MACRO IC.
registers. Generally, this requires writing to either a PMAC2-style Servo IC or a MACRO IC.
Ixx61 is only used if Ixx82>0 to activate digital current-loop execution.
Ixx62 Motor xx Current-Loop Forward-Path Proportional Gain
Range:
0.0 - 2.0 (24-bit resolution)
Units:
Output = 4 * Ixx62 * (I
cmd
- I
act
)
Default:
0
Ixx62 is the proportional gain term of the digital current loops that is in the “forward path” of the loop,
multiplying the difference between the commanded and actual current levels. Either Ixx62 or Ixx76 (back
path proportional gain) must be used to close the current loop. Generally, only one of these proportional
gain terms is used, although both can be. Ixx62 is only used if Ixx82>0 to activate digital current loop
execution.
multiplying the difference between the commanded and actual current levels. Either Ixx62 or Ixx76 (back
path proportional gain) must be used to close the current loop. Generally, only one of these proportional
gain terms is used, although both can be. Ixx62 is only used if Ixx82>0 to activate digital current loop
execution.
Ixx62 can provide more responsiveness to command changes from the position/velocity loop servo, and
therefore a higher current loop bandwidth, than Ixx76. However, if the command value is very noisy,
which can be the case with a low-resolution position sensor, using Ixx76 instead can provide better
filtering of the noise.
therefore a higher current loop bandwidth, than Ixx76. However, if the command value is very noisy,
which can be the case with a low-resolution position sensor, using Ixx76 instead can provide better
filtering of the noise.
Typically, Ixx62 is set using the current loop auto-tuner or interactive tuner in the Turbo PMAC
Executive or Setup program. Typical values of Ixx62, when used, are around 0.9.
Executive or Setup program. Typical values of Ixx62, when used, are around 0.9.
Digital current loop closure on the Turbo PMAC requires a set of three consecutive command output
registers. Generally, this requires writing to either a PMAC2-style Servo IC or a MACRO IC.
registers. Generally, this requires writing to either a PMAC2-style Servo IC or a MACRO IC.
Ixx62 is only used if Ixx82>0 to activate digital current-loop execution.
Ixx63 Motor xx Integration Limit
Range:
-8,388,608 - 8,388,607
Units:
(Ixx33 / 2
19
) counts * servo cycles
Default:
4,194,304
Ixx63 limits the magnitude of the integrated position error (the output of the integrator) for the PID servo
algorithm, which can be useful for anti-windup protection, when the servo loop output saturates. The
default value of Ixx63 provides essentially no limitation. (The integral gain Ixx33 controls how fast the
error is integrated.)
algorithm, which can be useful for anti-windup protection, when the servo loop output saturates. The
default value of Ixx63 provides essentially no limitation. (The integral gain Ixx33 controls how fast the
error is integrated.)
A value of zero in Ixx63 forces a zero output of the integrator, effectively disabling the integration
function in the PID filter. This can be useful during periods when applying a constant force and are
function in the PID filter. This can be useful during periods when applying a constant force and are