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Setting Up Parameters
Deceleration. When the Time check box is enabled, these parameters automatically become maximums for use in the
calculations.
Figure 105:
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.
The units for the Time parameter depend on the current setting of the Time Base parameter. If Time Base is set to "Realtime"
(default), then the units for the Time parameter are Seconds.The user can program the index time with resolution of 0.001
Seconds (or milliseconds). If Time Base is set to "Synchronized", the units for the Time parameter are defined by the Master
Distance Units found on the Master Units view.
Doing a synchronized Timed Index means that the user can specify the master distance in which the index should be
performed. This can be very useful in many synchronized motion applications.
The internal calculations are designed to calculate a triangular profile (all accel and decel) The ratio of acceleration to
deceleration will be the same ratio as Max. Acceleration to Max. Deceleration parameters. For example, if the deceleration
is desired to be twice the acceleration, a number twice the value of max acceleration would we entered for maximum
deceleration. If the Maximum Velocity is low enough such that the profile will become trapezoidal (some duration at max
velocity). Even in trapezoidal moves, the same ratio of acceleration and deceleration is maintained.
The calculations are based on the assumption that Feedrate Override is set to 100%. If set to greater that 100%, the motor
could run in excess of the specified Max. Velocity.
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