cui.com

date 10/13/2015

│ page 9 of 10

CUI Inc

│ SERIES: AMT31 │ DESCRIPTION: MODULAR COMMUTATION ENCODER

APPLICATION NOTES (CONTINUED)

The AMT31 series encoder requires minimal setup time for brushless DC (BLDC) motor applications. Installation can be completed

with either a PC with the AMT Viewpoint™ application installed, an AMT-OTZ-1 zero alignment module, or any 5V serial interface. The

following steps explain the proper commutation alignment procedure for the AMT31 encoder.

1. Ensure AMT31 encoder is set for correct pole count. To verify or change settings use the AMT Viewpoint™ software.

2. Mount encoder following AMT Assembly procedure.

3. Use the motor manufacturer’s documentation to determine the correct motor phase to energize for alignment. Energized phase

will coincide with the rising edge of the AMT31 encoders ‘U’ signal. This typically means energizing phase 1 by applying positive

voltage to the wire labeled ‘phase 1’, and grounding the wire labeled ‘phase 2’. The third wire always remains unconnected.

4. Using a power supply, energize the two wires found previously. This will lock the rotor into a fixed position.

5. Connect AMT31 encoder to an AMT-OTZ-1 zero alignment module, the AMT Viewpoint™ application, or any suitable 5V serial

interface.

6. Use any of the connected devices to issue an alignment command to the encoder. This will digitally set the rising edge of ‘U’ and

the ‘Z’ index to the current angular position.

7. Remove power from motor phase windings; connect motor and encoder to proper motor driver.

8. If the above is done correctly your AMT31 encoder is now ready for operation. As a verification of alignment you may power the

encoder, and use an oscilloscope to monitor phase 1 of the motor and the ‘U’ channel of the encoder as you hand spin the motor.

If alignment is correct, the square wave generated on the ‘U’ channel will overlap perfectly with the sine wave generated by phase

1 of the motor. If alignment does not match, recheck motor documentation and retry alignment procedure.

COMMUTATION ALIGNMENT AND ZERO POSITION

For more information, please visit the product page.