DMC-1000
Chapter 2 Getting Started
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13
(channel A), XB+ (channel B), and XI+. For differential encoders, the
complement signals are labeled XA-, XB-, and XI-.
Note:
When using pulse and direction encoders, the pulse signal is
connected to XA+ and the direction signal is connected to XB+. The
controller must be configured for pulse and direction with the
command CE. See the command summary for further information on
the command CE.
Step D.
Verify proper encoder operation.
Start with the X encoder first. Once it is connected, turn the motor
shaft and interrogate the position with the instruction TPX <return>.
The controller response will vary as the motor is turned.
At this point, if TPX does not vary with encoder rotation, there are
three possibilities:
1.
The encoder connections are incorrect - check the wiring as necessary.
2.
The encoder has failed - using an oscilloscope, observe the encoder signals. Verify
that both channels A and B have a peak magnitude between 5 and 12 volts. Note
that if only one encoder channel fails, the position reporting varies by one count
only. If the encoder failed, replace the encoder. If you cannot observe the encoder
signals, try a different encoder.
3.
There is a hardware failure in the controller- connect the same encoder to a different
axis. If the problem disappears, you probably have a hardware failure. Consult the
factory for help.
Step 7a. Connect Standard Servo Motors
The following discussion applies to connecting the DMC-1000 controller to standard servo motor
amplifiers:
The motor and the amplifier may be configured in the torque or the velocity mode. In the torque
mode, the amplifier gain should be such that a 10 Volt signal generates the maximum required current.
In the velocity mode, a command signal of 10 Volts should run the motor at the maximum required
speed.
Step by step directions on servo system setup are also included on the WSDK (Windows Servo Design
Kit) software offered by Galil. See section on WSDK for more details.
Step A.
Check the Polarity of the Feedback Loop
It is assumed that the motor and amplifier are connected together and
that the encoder is operating correctly (Step B)
. Before connecting the
motor amplifiers to the controller, read the following discussion on
setting Error Limits and Torque Limits. Note that this discussion only
uses the X axis as an example..
Step B.
Set the Error Limit as a Safety Precaution
Usually, there is uncertainty about the correct polarity of the feedback.
The wrong polarity causes the motor to run away from the starting
position. Using a terminal program, such as DMCTERM, the
following parameters can be given to avoid system damage:
Input the commands:
ER 2000 <CR>
Sets error limit on the X axis to be 2000 encoder
counts
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