Tachometer calibration – Rockwell Automation 1771-QC , D17716.5.25 SER/B SERVO POS User Manual
Page 209
Integrating Axes
Chapter 9
9Ć8
11. Observe following error for axis motion in both directions at various
speeds by jogging the axis. At each speed, following error should be
the same for axis motion in both directions.
12. Jog the axis back and forth within its range of travel. Use feedrate
override to vary axis speed. Verify that axis motion is smooth and
stable at all speeds, including rapid traverse, in both directions. If it
is not, check parameter block values for initial gain, in-position band,
gain break speed, and gain reduction factor. These parameters can
influence axis stability and positioning accuracy and may require
minor adjustment at this point. If necessary, adjust the servo drive
according to the manufacturer’s instructions to obtain the desired
results.
Repeat this closed-loop integration procedure for each axis.
For the loss-of-feedback detection feature to function correctly, you must
calibrate the 1771-ES expander. Follow these steps:
1. Turn on bit 15 (enable loss-of-feedback detection) of the home
position value word in the parameter block (word 17 for axis 1, word
36 for axis 2, word 55 for axis 3).
WARNING: Once you have completed the axis integration
procedures, never turn this bit off. Without loss-of-feedback
detection, if encoder or tachometer feedback is lost, unexpected
axis motion can occur, resulting in damage to equipment and/or
injury to personnel.
2. Turn on the tachometer calibrate bit (bit 16) of axis control word 2 in
the command block.
3. Set the tach fine potentiometer on the 1771-ES expander to its fully
clockwise position. Set the tach coarse potentiometer to its fully
clockwise position (Figure 9.3).
Tachometer Calibration