DMC-18x6 Command Reference
90
FA
FUNCTION: Acceleration Feedforward
DESCRIPTION:
The FA command sets the acceleration feedforward coefficient. 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 operates when commanding motion with
PA, PR and JG.
ARGUMENTS: FA n,n,n,n,n,n,n,n or FAS=n where
n is an unsigned number in the range 0 to 8191 decimal with a resolution of 0.25.
n = ? Returns the value of the feedforward acceleration coefficient for the specified axis.
USAGE: DEFAULTS:
While Moving
Yes
Default Value
0
In a Program
Yes
Default Format
4.2
Command Line
Yes
Controller Usage
ALL CONTROLLERS
OPERAND USAGE:
_FAn contains the value of the feedforward acceleration coefficient for the specified axis.
RELATED COMMANDS:
Velocity feedforward
EXAMPLES:
AC 500000,1000000
Set feedforward coefficient to 10 for the A-axis
FA 10,15
and 15 for the B-axis. The effective bias will be 0.75V for A and 2.25V
for B.
FA ?,?
Return A and B values
10, 15
Note: If the feedforward coefficient is changed during a move, then the change will not take effect until the
next move.
