Prior Scientific ProScan III Manual page 68

ProScan® III Manual
When the controller identifies an encoder fitted to any axis for the first power-up this
prompts a small motion to be initiated (two full steps of the motor). The controller will
use the number and sign of the counts from the encoder to establish the correct ratio
between encoder pulses and motor pulses.
The stage can be sent to a position using internal stepper position or encoders using the
ENCODER Command. If the stage is fitted with encoders which are disabled the 'P,s' and
'P,e' Command can be used to compare the stepper and encoder position. This facility
may be useful for application software where stage calibration is required.
Stepper moves will be faster than moves under encoder control due to the
feedback, checking, and adjusting required for the closed loop system.
The SERVO, b command gives the option for the controller to constantly read the
encoder position (when stationary) and correct for any position drift.
b=1 SERVO on
b=0 SERVO off.
This is a global command that affects all axes fitted with encoders.
With SERVO off, the axis still moves to its destination positions measured by the
encoder but will not correct for any drift once the destination has been reached.
This command refers to ALL axes which have encoders fitted (and enabled).
Command Arguments
ENCODER none
ENCODER b
ENCODER Axis
ENCODER Axis,b
SENCODER As above
© Prior Scientific Instruments Ltd
Response Description
Reports back as a decimal number the axes that are operating
n using the encoders. For example, 3 means X and Y axes are
using the encoders.
b=0 Disables ALL encoders
0
b=1 Enables ALL encoders.
Returns whether the individual axis have encoder enabled or
0,1 disabled.
Axis = S,X,Y,Z,A.
b=0 Disables encoder specified by Axis
0
b=1 Enables encoder specified by Axis.
Behaves like the ENCODER commands above except that it
forces the encoder and motor positions to be the same when
enabling and disabling encoder function.
Version 1.12 June 2017 Page 66