Electronic Cam (E-Cam) - Delta ASDA-A2 Series User Manual

7.11 Electronic Cam (E-CAM)

The concept of electronic cam (E-CAM) is to set the position relationship between master axis (Master) and
slave axis (Slave), almost like an electronic cam exists between both of them. Please refer to the figure
below.
In Pt mode, the external input pulse number (Master) is the reference value of the position command (Slave).
The relation between master and slave axis is a linear relationship (The ratio is electronic gear ratio).
However, when electronic cam function is enabled, the relation between Master and Slave is no longer a
linear relationship only and will become a cyclic curve relationship, just like the E-CAM profile. In the
application of machinery, using electronic cam can make the master axis which operates in a constant speed
become the slave axis and perform a wide range of motion control operation, such as variable speed motion
control, reciprocating motion control and intermittent motion control, etc. operation. The electronic cam
provides almost the same function. Using electronic cam can make the servo drive to be used for a variety of
motion control applications. For the differences between substantial cam and electronic cam, please refer to
the table below:
Return to the original position after
Structure
one rotation.
Smooth Determined by actual process
Performance precision
Position The position accuracy is very precise
Accuracy (under the condition of no vibration)
When the motion distance is longer,
Long Motion
the system needs bigger cam. The
Distance
production of big cam is not easy.
Eliminate Master
Master axis can not be eliminated
Axis
Revision April, 2010
Chapter 7 Motion Control Function|ASDA-A2 Series
Substantial CAM Electronic CAM
After E-CAM rotates for one revolution, it not
only can return to the original position but also
can display by spiral form like mosquito coil
incense.
Three curves can be interpolated between two
positions upon software.
The position accuracy is very precise, but the
actual motor position will be a little deviated
due to the delay time.
Only need to change the values of E-CAM
table. It is applicable for the application of long
motion distance.
Master axis can be eliminated for constant
speed motion application. The users can use
the signals that generated by the servo drive.
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