DMC-1400 Series Command Reference FA ● 89
FA FUNCTION: Acceleration Feedforward
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.
ARGUMENTS: FA n where
n is an unsigned number in the range 0 to 8191 decimal
“?” returns the value of the feedforward acceleration coefficient.
FA has a resolution of .25
USAGE:
While Moving Yes Default Value 0
In a Program Yes Default Format 4.0
Command Line Yes
Can be Interrogated Yes FA ?
Used as an Operand Yes
Controller Usage ALL
OPERAND USAGE:
_FA contains the value of the feedforward acceleration coefficient.
RELATED COMMANDS:
FV Velocity feedforward
EXAMPLES:
AC 500000 Set feedforward coefficient to 10.
FA 10 The effective bias will be 0.75V
FA ? Return value
010
NOTE: If the feedforward coefficient is changed during a move, then the change will not take effect
until the next move.