Emerson SM-EZMotion Module P/N 400361-00 - Page 53

Configuring an Application www.emersonct.com 39
synchronized motion throughout the software. Using a high
number of decimal places will improve position resolution,
but will also limit the maximum position. You can select
from zero to six decimal places of programming resolution.
Master Distance Units Scaling
The scaling factor is defined as following:
The numerator (top value of the scaling fraction) is the
Characteristic Distance. The Characteristic Distance is the
number of Master Distance Units that will be traveled per
number of revs defined in the bottom value of the fraction.
The denominator (bottom value of the scaling fraction) is
the # of encoder revolutions. The master revs parameter is
the number of incoming whole revolutions it takes to travel
the specified characteristic distance.
Master Position Filter Enable
The enable check box is used to turn on or turn off the
Master Position Filter. If checked, the filter is active and the
user must select the number of samples used by the filter.
If unchecked, the filter is not used
Master Position Filter Samples
Defines the number of samples used by the filter to smooth
the master signal. Increasing the number of samples
increases smoothness, but also increases lag. See Filter
table below to select proper setting.
Enable Feedforward
The Enable Feedforward Check Box is used to turn on or
turn off feedforward. If checked, feedforward is active. If
unchecked, feedforward is not used.
Scaling
MasterDistUnitsCharacteristicDis cetan
MasterDistUnitsEncoderRevs
-------------------------------------------------------------------------------------------------------------------=
Feedforward OFF Feedforward ON
# of
Samples
Disabled
One update of phase shift
(not velocity dependent)
No Filtering
No delay,
No Filtering
4
Small Lag (function of speed),
Low Filtering
Poor at low speed,
Low Filtering
8
Medium Lag (function of speed),
Medium Filtering
Good at low speed,
Medium Filtering
16
Large Lag (function of speed),
High Filtering
Best at low speeds,
High Filtering
Smoother
Increasing Lag
with FF Off
Reduced Lag