Delta RMC151 - Manual (Page 1006)

RMC70/150 and RMCTools User Manual
The Output Deadband applies to pressure/force control. If the Deadband Tolerance value
is non-zero, then the Output Deadband will not apply if the Target Pressure or Target
Force is zero. Otherwise, the value of the Deadband Tolerance has no meaning.
Pressure/Force Limit on Position-Pressure or Position-Force Axes
The Output Deadband is applied as normal, based on position. The Deadband Tolerance is
applied based on the position as normal. Notice that if the axis is pressure/force limited,
the position may be outside the tolerance window, and the full compensation will apply.
The Deadband Tolerance controls the integrator for the position component. If the target
is stopped and the position error is less than the window then the position of the
integrator is only allowed to wind down. When the axis is pressure/force limited then the
position integrator is not used and the Deadband Tolerance has no effect.
Why Bother?
On an axis with overlapped spools or a large amount of static friction, the axis may
oscillate slowly around the Command Position. This happens when the axis does not
respond to small changes in Control Output. The integrator winds up until the axis moves
and then has too much Control Output, overshooting the Command Position. The axis
then winds the integrator down until the axis overshoots the other way.
If this happens, look at the Control Output. The Control Output will oscillate slowly as the
axis oscillates. Notice the peak-to-peak values of the Control Output oscillation and
subtract the minimum value from the maximum value and then divide the result by two.
Enter this value in the Output Deadband register as a starting point.
A spool that has 10% overlap will require a value of about 1 Volt.
9.2.2.6.6. Output Filter
Type: Axis Parameter Register
RMC70 Address: Primary Input: %MDn.39, where n = 12+ the axis number
Secondary Input: %MDn.40, where n = 12+ the axis number
RMC150
Address:
Primary Input: %MDn.39, where n = 24+ the axis number
Secondary Input: %MDn.40, where n = 24+ the axis number
System Tag: Primary Input: _Axis[n].OutputFilterFreq, where n is the axis
number
Secondary Input: _Axis[n].PFOutputFilter, where n is the axis
number
How to Find: Axes Parameters Pane, Tune tab
Data Type: REAL
Units: pu/sec 2
Range: 0, ≥ 0.01
Default Value: 0
Description
This parameter specifies the cut-off frequency of the low-pass single pole filter that is
applied to the output. This filter is actually applied only to the Proportional, Differential,
Double Differential, and Triple Differential gains in closed-loop control.
Setting the Output Filter to zero (0) disables the filter.
Dual-loop axes have an output filter for each loop, that is, one for the primary control and
one for the secondary control.
986 Delta Computer Systems, Inc.