R325P User Manual
Page
19
of
20
1/31/2013 Version 1.0
11.
Appendix
B:
PF
Value
For
applications
requiring
ultimate
smoothness
of
motion
and
extreme
accuracy,
the
R325P
driver
can
be
programmed
via
RS485
to
change
the
Percent
Fast
Decay
rate,
or,
the
PF
value.
The
Percent
Fast
Decay
default
is
2,
or
a
mixed
mode
of
48%.
Mixed
mode
is
a
damping
technique
done
to
the
driver
IC.
The
following
values
indicate
the
choices
for
Percent
Fast
Decay:
PF
Values
(0
through
3):
0
=
Slow
Decay
1
=
Mixed
Mode
15%
2
=
Mixed
Mode
48%
3
=
100%
Fast
Decay
Generally
speaking,
applications
that
run
at
slow
speeds
are
recommended
to
use
a
PF
value
of
1
or
less.
Fast
speeds
should
use
a
PF
value
of
2
or
more.
Since
the
best
PF
value
is
dependent
on
the
motor
winding,
loads,
power
supply
voltage,
and
other
factors,
it
is
best
to
use
an
oscilloscope
and
a
current
probe
device
to
view
the
current
waveform
and
try
different
PF
values.
The
following
examples
show
good
and
bad
waveforms
when
choosing
different
PF
values.
PF
value
1
Slow
speeds
Good
waveform
