MCi iControl User Manual page 163

• Slope of Acceleration / Deceleration - Ideally, the slope of acceleration in volts per
second should be equal to or slightly greater than the slope of deceleration as viewed on an
oscilloscope connected to iBox test point STP1 and COM (with Virtual Oscilloscope Test
point 1 set to Speed Feedback Filtered). To get approximately equal acceleration and
deceleration speeds in a system where tracking accuracy is very good, Acceleration can be
equal to Deceleration. If tracking is less accurate, set Acceleration greater than Decelera-
tion to get the same effective rate of deceleration as acceleration.
• Final Approach to the Floor -
Final approach to the floor can be
customized in many different ways.
If tracking accuracy is very good, you
can probably program as follows on
the iView Pattern > Common tab:
• Leveling speed = Your desired
leveling speed. A typical number
is from 2 to 4.
• Leveling Distance = your choice. A typical number is from 0.12 to 0.25.
If tracking is not perfect, you can begin to introduce values in Leveling Speed and Dis-
tance that allow you to mold the shape of the last few inches of approach.
• Excessive Motor Noise - If there is excessive motor noise or if acceleration or decelera-
tion feels rough, reduce Acceleration and/or Deceleration to provide the desired results.
Also, verify that:
• TORQMAX Drive - At lower speeds the drive automatically selects a lower carrier fre-
quency to produce more current from the drive. If required, adjust LF.38 Switching
Frequency = 0. This will set the carrier frequency to 8 KHz. In addition, reduce drive
gain value, LF.31 and LF.32. DO NOT reduce LF.31 below 1200 or LF.32 below 800 as
a loss of control will result.
• Bunching up of Deceleration Rate - If you are observing a bunching up of decelera-
tion rate (an increase in the deceleration rate as you reach the last few feet of approach to
the floor), it is generally due to inaccurate tracking. You must improve accuracy or lower
the value of the Flare Jerk and/or Approach Jerk parameters. Remember that there are
very real limits to how low you can set these parameters (1.75 ft/s
can go).
Shaping the Speed Profile
3
is often as low as you
4
4-15