Data Sheet

Hall and other Rotor Sensor Inputs
Advanced Digital Motor Controller User Manual 65
The count information is also used to measure rotation speed. Using the Encoder Pulse
Per Rotation (PPR) configuration parameter, the output is a speed measurement in actual
RPM that is useful in closed loop speed modes where the desired speed is set as a nu-
merical value, in RPM, using a serial command.
The speed information is also scaled to produce a number ranging from -1000 to +1000
relative to a user-configured arbitrary Max RPM value. For example, with the Max RPM
configured as 3000 and the a motor rotating at 1500 RPM, the measured relative speed
will be 500. Relative speed is useful for closed loop speed mode that use Analog or Pulse
inputs as speed commands.
Configuring the encoder parameters is done easily using the PC Configuration Utility.
Hall and other Rotor Sensor Inputs
On brushless motor controllers, the Hall or other Rotor position sensor that are used to
switch power around the motor windings, are also used to measure speed and distance
traveled.
Speed is evaluated by measuring the time between transition of the Hall Sensors. A 32 bit
up/down counter is also updated at each Hall Sensor transition.
Speed information picked up from the Hall Sensors can be used for closed loop speed op-
eration without any additional hardware.