Trio Motion Coordinator Euro 205, Technical Reference Manual

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8-172 Trio BASIC Commands
Axis Parameters
Trio Motion Technology
Note: Negative values are normally required. Servo gains have no effect on stepper motor
axes.
PP_STEP
Type:
Axis parameter
Description: This parameter allows the incoming raw encoder counts to be multiplied by an inte-
ger value in the range -1024 to 1023. This can be used to match encoders to high
resolution microstepping motors for position verification or for moving along circu-
lar arcs on machines where the number of encoder edges/distance do not match on
the axes. Using a negative number will reverse the encoder count.
Example: A microstepping motor has 20000 steps/rev. The Motion Coordinator is working in
MICROSTEP=ON
mode so will internally process 40000 counts/rev. A 2500 pulse
encoder is to be connected. This will generate 10000 edge counts/rev. A multiplica-
tion factor of 4 is therefore is required to convert the 10000 counts/rev to match
the 40000 counts/rev of the motor.
PP_STEP AXIS(3)=4
Example 2: An X-Y machine has encoders which give 50 edges/mm in the X axis (Axis 0) and 75
edges/mm in the Y axis (Axis 1). Circular arc interpolation is required between the
axes. This requires that the interpolating axes have the same number of encoder
counts/distance. It is not possible to multiply the X axis counts by 1.5 as the
PP_STEP
parameter must be an integer. Both X and Y axes must therefore be set to
give 150 edges/mm:
PP_STEP AXIS(0)=3
PP_STEP AXIS(1)=2
UNITS AXIS(0)=150
UNITS AXIS(1)=150
Note:
If used in a Servo axis, increasing PP_STEP will require a proportionate decrease of
loop gain.