User guide

LA Stand-Alone Product User Guide
Revision A7
Page 31
5 Troubleshooting
5.1 Autobalance
The amplifier has a built-in algorithm for balancing the linear amplifier power stage. Normally it is not
necessary to perform this procedure as the amplifier stage is balanced at the factory. Due to the inherent
offsets of the analog circuitry in the power stage, offsets may occur in the system over time that cause
unwanted torque ripple. Offsets can be detected in open loop mode by commanding 0 current and rotating
the motor by hand and feeling for “detents”. If any significant detents are found, balancing may be
necessary.
To Autobalance the system, the following procedure is used:
1) Run the system to operating temperature.
2) Lock the motor such that no motion can be commanded by the controller when current is applied.
3) Issue a "B" command over the serial interface. Alternatively the procedure can be started by
accessing the amplifier module under the top cover and pressing the S1 reset switch for greater
than 1 second. Note: The reset switch on the front panel will not initiate Autobalance.
The middle bar on the LED display will illuminate indicating Autobalance is in progress.
4) Autobalance is now running and may take up to 1 minute to complete.
5) When the Autobalance algorithm completes successfully (“C” or “0” on display), issue a “S”
command to save the final settings in the amplifier. If this save is not performed, a power on reset
will return the balance to the pre-autobalance settings.
6) If Autobalance cannot complete, a “4” error code will be on the display. This indicates the
controller is unable to balance the motor. Reset the system and try again to Autobalance.
Autobalance errors can be due to motor movement, very low resistance (<1 ohm), severely out of
range balance in the amplifier, or other internal problems. Please contact the factory for
assistance if repeated attempts to Autobalance fail.