How do I configure my shunt resistor in MotionLab3?

Before starting

This FAQ assumes that the shunt braking resistor in your system has been properly dimensioned from your side. If that is not the case, please refer to the following link in order to get a calculation of the exact shunt resistor that your axis will require: Dimensioning a Shunt Resistor for Regenerative Braking

First of all, it is important to clarify that the Everest XCR/NET servo drives do not have a shunt regulator transistor so it is always required to have an external circuitry handling the activation and deactivation of the shunt. For the Everest NET, you can check the application guide on how to design this shunt circuitry on your PCB board: https://novantamotion.atlassian.net/wiki/spaces/EC/pages/28213952.

However, you can still configure a digital output based on the voltage readings on the DC bus input stage so that it can trigger the activation of this external shunt transistor and circuitry. The registers involved in this are the following (for more detailed explanations, check the Shunt braking resistor section of the manual):

• External shunt enable voltage (key 0x122) in volts
• External shunt disable voltage (key 0x123) in volts