Galil Motion Control DMC-42 0 Series, User Manual

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3. Move the motor by hand and re-issue
TP
. The returned value should have been incremented or
decremented from the first
TP
. If there is no change, check the encoder wiring and settings and
retest starting at Step 1.
4. Using the encoder specification sheet, translate a physical distance of the motor into counts read
by the controller. For example, a 2000 line encoder means that the controller reads 2000*4=
8000 counts/revolution and a half turn of the motor would be 4000 counts.
5. Issue
TP
to determine the current motor position, record this value.
6. Move the motor by hand some measured physical distance.
7. Query
TP
again. Take the absolute difference from the current
TP
and the
TP
recorded from
Step 5.
8. Determine if the physical distance moved is equal to the expected amount of counts calculated in
Step 4, move on to Step 9. Otherwise, check the encoder wiring and settings and retest starting
at Step 1.
9. Perform Step 5-8 again, instead moving a physical distance in the opposite direction. If the
physical distance correctly translates to the expected amount of counts, the encoder is wired
correctly.
Step D. Reverse encoder direction, if necessary
Table 2.2 below provides instructions for how to reverse the direction of feedback by rewiring the encoder to the
DMC controller. The direction of standard, quadrature encoders can be be reversed using the
CE
command.
NOTE
Reversing direction of the feedback may cause a servo motor to runaway, see Step 8. Setting
Safety Features before Wiring Motors, pg 15 regarding Runaway Motors.
Feedback Type Directions
Standard Quadrature
Differential Swap channels A+ and A-
Single-ended Swap channels A+ and B+
SSI or BiSS Follow encoder manufacturer's instructions.
Analog feedback Cannot change the direction of feedback without external hardware to invert
analog signal. 1
Table 2.2: Directions for reversing feedback direction based upon feedback type
1
The polarity of the control loop may still be inverted by either re-wiring the motor or using the MT command, see Step 8.
Setting Safety Features before Wiring Motors, pg 15 regarding positive feedback loops.
Step 8. Setting Safety Features before Wiring Motors
This section applies to servo motors only.
Step A. Set Torque Limit
TL will limit the output voltage of the ±10V motor command line. This output voltage is either translated into
torque or velocity by the amplifier (Galil's internal amplifiers are in torque mode). This command should be used to
avoid excessive torque or speed when initially setting up a servo system. The user is responsible for determining
the relationship between the motor command line and the amplifier torque/velocity using the documentation of
the motor and/or amplifier.
See the
TL
setting in the Command Reference for more details.
See the
AG
command in the command reference for current gains of Galil's internal amplifiers. The amplifier gain
can also be used to change the ratio of outputting amps of the amplifier per commanded volts of the controller.
Chapter 2 Getting Started ▫ 15 DMC-42x0 User Manual