User`s manual
Startup and Tuning
GFK-1742A Appendix D Tuning GE Fanuc Digital and Analog Servo Systems D-15
D
6. Send the command code for
Force D/A Output
equal to +3200 (+1.0v). Confirm that the
motor moves in the desired POSITIVE direction (based on the
Axis Direction
configuration
parameter setting) and the
Actual Velocity
reported in the DSM314 %AI table is POSITIVE.
If the motor moves in the wrong direction, consult the servo amplifier manufacturer's
instructions for corrective action. The
Axis Direction
parameter in the
Configuration
Software
can also be used to swap the positive and negative axis directions. If the motor
moves in the POSITIVE direction but the DSM314 reports that
Actual Velocity
is
NEGATIVE, then the encoder channel A and channel B inputs must be swapped.
7. Record the actual motor velocity reported by the Motion Mate DSM314 with a 1.0 volt
velocity command. Multiply this velocity by 10 and update the
Velocity at Max Cmd
entry in
the DSM314 configuration, if necessary. Initially set the
Pos Loop Time Constant (0.1 ms)
configuration parameter to a high value (typically 100 ms or a value of 1000 in the
configuration).
8. Turn on the %Q
Jog Plus
bit. Confirm that the servo moves in the proper direction and that
the
Actual Velocity
reported by the Motion Mate DSM314 in the %AI table matches the
configured
Jog Velocity
. If Motion Programs will use an acceleration higher than
the Jog
Acceleration
, it may be necessary to increase
Jog Acceleration
so that
Abort All Moves
and
Normal Stop actions will operate as expected.
9. With the
Drive Enabled
%Q bit ON and no servo motion commanded, adjust the servo drive
command offset adjustment for zero
Position Error
. The integrator should be OFF during
this process.
10. Check for proper operation of the
Find Home
cycle by momentarily turning on the %Q
Find
Home
bit (the
Drive Enabled
%Q bit must also be maintained ON). The axis should move
towards the Home Switch at the configured
Find Home Velocity
, then seek the Encoder
Marker at the configured
Final Home
Velocity
. If necessary, adjust the configured velocities
and the location of the
Home Switch
for consistent operation. The final
Home Switch
transition MUST occur at least 10 ms before the Encoder Marker Pulse is encountered. The
physical location of
Home Position
can then be adjusted by changing the
Home Offset
value
in the Configuration Software.
11. Monitor servo performance and use the %Q
Jog Plus
and
Jog Minus
bits to move the analog
servo motor in each direction. The
Position Loop Time Constant
can be temporarily
modified by placing the correct command code in the %AQ table. For most systems
the
Position Loop Time Constant
can be reduced until some servo instability is noted, then
increased to a value approximately 50% higher. Once the correct time constant is determined,
the DSM314 configuration should be updated using the Configuration Software.
Velocity
Feedforward
can also be set to a non-zero value (typically 90-100 %) for optimum servo
response.
Note
For proper servo operation, the Configuration entry for
Velocity at Max Cmd
MUST be set to the actual servo velocity (in User Units/sec) caused by a 10 Volt
Velocity command to the amplifier.