Motor(s) and Positioning Table
The motor(s) will most likely be driving a positioning table. Motor travel will be sensed either by:
a rotary encoder mounted onto the motor shaft, or
a linear encoder mounted onto the positioning table
In either case, the encoder signals are fed back to the Controller card to enable it to close the servo positioning
loop.
Why both the Hall-sensor feedback and the encoder feedback?
the Hall-sensor feedback allows the amplifier to generate the proper current waveforms for
brushless motors
the encoder feedback tells the Controller card what the motor's current position is.
Section 1-1.2 Two-Axis System
Figure 1-2 shows a block diagram of a two-axis system.
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Figure 1-2 Two-Axis System
We see that there are two, independent servo loops; one for the X-axis, and the other for the Y-axis.