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MOTION CONTROL
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Controlling Moves In Progress (continued)
Absolute, Relative and Encoder Moves
Absolute, Relative and Encoder Moves can be placed in a Hold state and resumed if error conditions, such as
programming errors, have not occurred. New Acceleration, Deceleration, and Programmed Speed parameters
can be written to the SD17060E while these moves are in their hold states. If the parameters are accepted
without error, the move can be resumed and it will use the new parameter values. Note that a change to the
Target Position is ignored.
Blend Moves
A Blend Move can be placed in it Hold state but cannot be resumed. This give you the ability to prematurely
end a Blend Move with a controlled stop. The Blend Move is not erased from memory and can be run again
without reprogramming it.
Electronic Gearing
The final form of motion control available with the SD17060E is Electronic Gearing. A quadrature encoder
is required but it is not mounted on the motor controlled by the SD17060E. The encoder is typically mounted
on a second motor, but it can be mounted anywhere, including on something as simple as a hand crank.
This mode is sometimes referred to as encoder following, because the motor will change position in response
to a change in position of the encoder. AMCI refers to it as Electronic Gearing because the SD17060E has
four parameters that allow you to set any turns ratio you want between the encoder and the motor.
Encoder Pulses Per Turn
This parameter sets the number of pulses generated by the encoder for one complete rotation of its shaft. This
parameter has a range of 0 to 65,535. The SD17060E always used X4 decoding when counting pulses from
the encoder. Therefore a 1,024 line encoder will generate 4,096 counts per rotation in the SD17060E.
Steps per Turn
This is the same parameter explained at the beginning of this chapter. It sets the number of steps required to
complete one rotation of the shaft of the motor driven by the SD17060E. It has a range of 200 to 32,767.
ELGearing Multiplier and Divisor
The ratio of these two parameters sets the number of motor rotations per encoder rotation. Each parameter
has a range of 1 to 255.
You must also set the Acceleration and Deceleration parameters before you can put the
SD17060E in Electronic Gearing mode.
How It Works
Once placed in Electronic Gearing mode, the SD17060E monitors the encoder inputs for a change in position.
When a change is sensed, the SD17060E will begin to turn the motor within 50 µseconds. An increase in
encoder counts will result in clockwise rotation. A decrease in encoder counts will result in counter-clock-
wise rotation.
The values of the ELGearing Multiplier and Divisor can be changed while electronic gearing motion is occur-
ing. The SD17060E will accelerate or decelerate the motor to match the new ratio.
