User guide

54 www.controltechniques.com SM-EZMotion Module User Guide
7.3.6.2 Ramps
7.3.6.2.1 Stop Deceleration
The value you enter here defines the deceleration rate
which is used when the Stop destination is activated. The
default is 100 RPM/second.
The Stop destination is found in the Ramps Group in the
Assignments view.
7.3.6.2.2 Feedhold Decel/Accel
When the Feedhold destination is activated, the motor will
decelerate to a stop in the time specified by the
FeedholdDecelTime parameter. When feedhold is cleared,
the motor will accelerate back to speed in the same
specified period of time.
Feedhold is a means to halt the motor within a velocity
profile and then return to the profile later at the exact same
place in the profile. Feedhold does not ramp and does not
decelerate in terms of velocity. Instead, it stops by
decelerating time. For example, if the motor is running at
50 revs/second and feedhold is activated with 2 seconds
specified in the FeedholdDecelTime parameter, then the
motor will actually slow and stop in 2 seconds as measured
time (on a time/velocity profile) goes from 100% to 0%.
7.3.6.2.3 Travel Limit Deceleration
The value entered here is the deceleration ramp that is
used when a software or hardware travel limit is hit.
7.3.7 Current View
The Current View allows the user to configure Current
Level Flags and Current Limits for use in the application.
Figure 75: Current View
7.3.7.1 System Ratings
This box is used only to show the user what current will be
available from the system based on user-entered
information. There are two columns of information based
on Continuous and Peak ratings for the different system
components and for the system as a whole. The first row
shows the Continuous and Peak current rating for the
selected Motor. The next row then shows the ratings for the
Drive itself, which may be higher or lower than those of the
motor. The last row called “System” shows the Continuous
and Peak current ratings for the motor/drive combination.
The system continuous and peak ratings are the lower of
the two motor and drive ratings. The Current limit on this
view is entered in units of % Cont. This means that the limit
entered is a percentage of the System Continuous Current
rating. Therefore, if the system continuous current is equal
to 15 Amps, and the Current Limit is set to 145%, the
current will actually be limited to 15 x 1.45 = 21.75 Amps
(remember the Current Limit Enable must be active to limit
the current).
If the Motor current rating is lower than the Drive current
rating, then the system is said to be “Motor Limited”. If the
Drive current rating is lower than the Motor current rating,
then the system is called “Drive Limited”.
7.3.7.2 Limits
7.3.7.2.1 Current Limit
This parameter sets the value to which the Current
Command will be limited when the Current Limit Enable
destination is active. To make the Current Limit always
active, assign the Current Limit Enable destination to the
Initially Active source on the Assignments view.
7.3.7.3 Settings
7.3.7.3.1 Current Level
This parameter sets the activation point for the Current
Level Active source. If set to 100%, the Current Level
Active source will activate any time the Current Command
reaches or exceeds 100% continuous.
7.3.8 Tuning View
The Tuning View contains all the parameters that are
adjusted to properly tune the motor/drive system. Figure 76
shows an example of the Tuning View.