Control Techniques Epsilon EP-P, Reference Manual

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Epsilon EP-P Drive Reference Manual
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www.controltechniques.com Revision: A4
Distance/Position
The Distance/Position parameter is a signed value which specifies the distance the index will travel (incremental index) or the absolute position
the index will move to (absolute index). In the case of an incremental index, this parameter also determines the direction the index will travel. If
an index type of Registration is selected, then this is a limit distance, or the maximum distance the index will travel if a registration sensor is not
seen.
Velocity
This sets the target velocity for the index profile. The velocity parameter is unsigned and must be greater than zero. Direction of the index is not
determined by the velocity, but by the Distance/Position parameter.
Acceleration
Average Acceleration rate used during the index. Units are specified on the User Units view.
Deceleration
The Deceleration parameter specifies the deceleration value to be used during the index in user units.
3.36.1 Timed Indexes
A Timed Index allows the user to specify the amount of time in which to perform an index rather than specifying the Velocity, Acceleration, and
Deceleration. The processor in the Epsilon EP-P drive will automatically calculate the necessary velocity, accel, and decel in order to achieve
the programmed distance in the specified time. A Timed Index can not be compounded into or out of.
All index types can be specified as a Timed Index, except for Registration and Posn Track type indexes. This is because these types of
indexes do not have a specified distance or absolute position. If a Registration or Posn Track type index is selected, then the Timed check box
will become disabled.
Based on the Distance entered (or Position for Absolute indexes) and the Time value specified, the calculations could result in extremely high
Velocities, Accels, and Decels. To avoid damage to mechanical parts, or potentially dangerous situations, the user is allowed to enter the
Maximum Velocity, Acceleration, and Deceleration used for the calculations. The results of the firmware calculations will never exceed the
maximum values specified.
Figure below shows a screen capture in which the Time check box has been enabled. Notice how the parameters which normally say Velocity,
Acceleration, and Deceleration have changed to say Max. Velocity, Max. Acceleration, and Max. Deceleration. When the Time check box is
enabled, these parameters automatically become maximums for use in the calculations.
Figure 108: Time Check Box Enabled
If the values for Max.Velocity, Max.Acceleration, and Max.Deceleration are such that the distance cannot be covered in the specified time, the
Index.ProfileLimited flag will activate when the index is initiated, indicating the index cannot be performed as desired. The internal calculation
are performed only when the index is initiated, and therefore is the only time the flag will activate. The Index.ProfileLimited flag will remain
active until cleared using the Index.ResetProfileLimited assignment or program instruction. In this situation, the index will still operate, but the
time will be extended. In other words, the profile will be performed using the maximums values and still cover the specified distance, but not in
the specified time.