Control Techniques Epsilon EP-P, Reference Manual

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46
Epsilon EP-P Drive Reference Manual
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www.controltechniques.com Revision: A4
progress, changes to this parameter will be ignored until the next motion is initiated. See the description of each of the ramp types below.
User Ramps Radio Button
Prior to the introduction of this feature, User Ramps was the only ramp control type available. When User Ramps are enabled, the Acceleration
or Deceleration ramp entered by the user will ALWAYS be used during a motion profile, even if that means the motor must overshoot the
entered stopping position. Under this circumstance, the acceleration or deceleration ramp would be honored, and therefore the motor may
need to reverse directions after coming to a stop in-order to reach the user entered target position. This scenario most often occurs when using
Compound or Blended Index instructions within a program. During Compound or Blended indexes, the user occasionally does not enter an
aggressive enough acceleration or deceleration ramp to reach the target velocity within the specified distance. See Figure 47 and Figure 48
below for examples of how User Ramps work. For more information on Index.#.CompoundInitiate and/or Index.#.BlendInitiats, see the
programming section of this manual.
Auto Calculate Ramps Radio Button
When Auto Calculate Ramps is selected the drive will automatically calculate the necessary ramp to reach the target velocity within the user
specified distance without any overshoot. In this scenario, the user entered acceleration of deceleration rate is ignored, See the figures below
for examples of how Auto Calculate Ramps work.
1. Index.1.Accel specified by user is used to decelerate from Index.0.Vel, to Index.1.Vel, but overshoots since ramp is not
aggressive enough to reach Index.1.Vel within Index.1.Dist of 3 Revs.
2. Index.1 begins at Index.1.Vel but since Index.1.Decel specified by user is not aggressive enough to decelerate to zero velocity
within Index.1.Dist of 3 Revs slight overshoot occurs.
3. Index.1 begins at Index.0.Vel and ramp is automatically calculated to reach zero speed within Index.1.Dist of 3 Revs without any
overshoot. If Index.1.Accel and or Decel were aggressive enough to reach zero speed within 3 Revs, they would have been used
instead of automatically calculating the ramp.
4. Index.1 begins at Index.1.Vel and ramps is automatically calculated to reach zero speed within Index.1.Dist of 3 Revs without
any overshoot. If Index.1.Decel was aggressive enough to reach zero speed within 3 Revs, it would have been used instead of
automatically calculating the ramp.
Figure 47: Ramps Examples of a Fast Index to a Slower Index
Distance
(Revs)
Velocity
(RPM)
Accel
(RPM/sec)
Decel
(RPM/sec)
Index 0 20 1250 2000 3000
Index 1 3 500 500 500
Blended Index
User Ramps
Compound Index
Auto Ramps
Blended Index
Auto Ramps
Compound Index
User Ramps
V
t
= Index 0
= Index 1
1
2
3
4
1250
500