Fa (acceleration feedforward), Setting, Fa has a resolution of .25 – Yaskawa LEGEND-MC User Manual
Page 122

112
LEGEND-MC User’s Manual
FA (Acceleration Feedforward)
[Setting]
DESCRIPTION:
The FA command sets the acceleration feedforward coefficient, or returns the previously set value. This
coefficient, when scaled by the acceleration, adds a torque bias voltage during the acceleration phase and
subtracts the bias during the deceleration phase of a motion.
Acceleration Feedforward Bias = FA
⋅ AC ⋅ 1.5 ⋅ 10
-7
Deceleration Feedforward Bias = FA
⋅ DC ⋅ 1.5 ⋅ 10
-7
The Feedforward Bias product is limited to 10 Volts. FA will only be operational during independent
moves, not gearing, camming or interpolation.
ARGUMENTS: FA x, y, z, w or FAX=x or FA a, b, c, d, e, f, g, h where
x, y z, w, or a, b, c, d, e, f, g, h are unsigned numbers
FA has a resolution of .25
USAGE:
OPERAND USAGE:
_FAn contains the value of the feedforward acceleration coefficient where n is an axis letter.
RELATED COMMANDS:
EXAMPLES:
NOTE: If the feedforward coefficient is changed during a move, then the change will not take effect
until the next move.
While Moving
Yes
Minimum Value
0
In a Program
Yes
Maximum Value
8191
Command Line
Yes
Default Value
0
Can be Interrogated
Yes
Default Format
4.0
Used as an Operand
Yes
Distributed Control
Specific Axis
"FV" Velocity
feedforward
AC 500000
Set acceleration
FA 10
Set feedforward coefficient to 10
FA ?
The effective bias will be 0.75V (10 * 500000 * 1.5 * 10
-7
)
010
Return value