Motor Brake

The axis supports an external brake control that can be controlled using the I.Axisxx.BrakeReleased tag.
The following example shows an output point (Pt00) of the 5034-OB16 module in slot 5 is used as the external brake control with normally closed. The 5034-STEPD module is in slot 2.
External Brake Control Ladder Diagram Example – Normal Operation
Brake is released when the axis is enabled (powered on). Brake is applied when the axis is disabled (powered off) or when the axis is de-energized due to a fault.
Use C.Axisxx.BrakeEngageDelayTime to configure the time from when the axis is disabled until the brake is applied. Use C.Axisxx.BrakeDisengageDelayTime to configure the time from Hold current is applied until the brake is released.
Motor Brake Timing Diagram
WARNING: Applying brake immediately when the axis is moving fast and there is too much inertia can cause the brake to shatter. You must configure proper delays for safe operation.
IMPORTANT: To help avoid the scenario where the brake control is active but the axis is not, the stepper module and the output point that is controlling the motor brake should be:
  • In the same backplane
  • Both have an RPI less than 50 ms

External Brake Faulted

If the stepper module connection to the controller is good but the output point that is configured as an external brake control is faulted, the ladder must check the fault bit of the output point and notify the stepper module by setting the O.Axisxx.BrakeFaulted tag. When O.Axisxx.BrakeFaulted is set to 1, the axis performs a hard stop.
You must configure the output point's behavior during Communication Fault Mode state:
  • If C.Axisxx.BrakeEngageDelayTime is 0, Communication Fault Mode = Off
  • If C.Axisxx.BrakeEngageDelayTime is greater than 0:
    • Communication Fault Mode = Hold
    • Communication Fault Mode Output State Durartion = 1 s
    • Communication Fault Mode Final Output State = Off
The following example shows an output point (Pt00) of the 5034-OB16 module in slot 5 is used as the external brake control. The 5034-STEPD module is in slot 2.
External Brake Control Ladder Diagram Example – Brake Fault
IMPORTANT: You must configure the ladder program with the output point's Final Output State During Communication Fault Mode to be Off.
The I.Axisxx.BrakeReleased tag continues to function normally even when O.Axisxx.BrakeFaulted is set.
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