ADLINK Technology PCI-8154, User Manual

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Operation Theory 39
4 Operation Theory
This chapter describes the detail operation of the motion controller
card. Contents of the following sections are as follows:
Section 4.1: Classifications of Motion Controller
Section 4.2: Motion Control Modes
Section 4.3: Motor Driver Interface
Section 4.4: Mechanical switch Interface
Section 4.5: The Counters
Section 4.6: The Comparators
Section 4.7: Other Motion Functions
Section 4.8: Interrupt Control
Section 4.9: Multiple Cards Operation
4.1 Classifications of Motion Controller
When motor/stepper control first started, motion control was
widely discussed instead of motor control. Motor control was sepa-
rated into two layers: motor control and motion control. Motor con-
trol relates to PWM, power stage, closed loop, hall sensors, vector
space, etc. Motion control relates to speed profile generating, tra-
jectory following, multi-axes synchronization, and coordinating.
4.1.1 Voltage motion control interface
The interfaces between motion and motor control are changing
rapidly. Early on, a voltage singal was used as a command to the
motor controller. The amplitude of the signal means how fast a
motor is rotating and the time duration of the voltage changes
means how fast a motor acceleration from one speed to the other
speed. Voltage signal as a command to motor driver is so called
“analog” motion controller. It is much eaiser to integrate into an
analog circuit of motor controller; however noise is sometimes a
big problem for this type of motion control. Also, to do positioning
control of a motor, the analog motion controller must have a feed-
back signal with position information and use a closed loop control
algorithm to make it possible. This increased the complexity of
motion control and not easy to use for a beginner.