Digital Halls

Digital halls are transducers that provide an electrical signal at its output proportional to the relative position of the shaft of a rotor to a predetermined reference. They are based on the Hall effect, and the output signal that they provide is discretized: in fact, very often they only provide a bit indicating presence or absence of magnetic field, being then also known as switches.

Digital halls able to measure position based on the transitions of the halls value.

The number of counts per mechanical revolution are:

The digital halls parameters to configure are:

Parameter

Description

Polarity

Define whether halls are active at high or low logical level. Use the Auto identify wizard to detect it. The main steps of the wizard are:

Set the current used for the test. Ranges is from 0 (min) to motor rated current (max).
Set maximum test duration.
Start the test to identify the halls polarity.
A message is displayed showing the result of the test. If the test ends successful, the suggested values are displayed in a grid. If the test fails, a message is displayed giving information about the failure and how to fix it by modifying the parameters in Step 1.

Hall step offset

Define the angular displacement (expressed in multiples of 60º) between the sequence of values generated by the Hall sensors and its corresponding excitation. This offset only applies when the system is using BLDC motors.

Quick Test

When configured for digital hall feedback, the drive will define 1 count to be equal to 1 hall state change (that is, a 4-pole motor has 12 counts per revolution).

The quick test monitors in real time the halls combination read by the drive and the equivalent actual position .

User can check proper halls wiring and operation by manually moving the motor and verifying halls sequence in the table.