Drive status & fault bits explained

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This page lists the behavior and function of status and fault bits registers that are readable from all Granite Devices drives.

Status bits register[edit | edit source]

Name Description Troubleshooting
Initialized True when drive has completed initialization procedure (such as phasing) If never goes on, check parameters, drive input voltage, safe torque off and enable inputs and possible faults.
Error recovering True when drive performs position return to the setpoint position after clear faults command is given
Tracking error warn Indicates that tracking error has increased beyond certain point. On most drives this controls a digital output pin that may be used in conjunction with controller to mitigate a tracking error problem before a tracking error fault is triggered. Operation depends on operating mode:
  • Position mode: true when position tracking error is greater than 1/8 of Position tracking error thresholdFPT
  • Velocity mode: true when velocity tracking error is greater than 1/8 of Velocity tracking error thresholdFVT
  • Torque mode: true when actual torque differs from torque setpoint more than 1/4 of Peak current limitMMC. This is not present in GraniteCore G2.0 devices (ARGON), and on that drive it will always read false.
Target reached True when drive's internal motion profiler (velocity & acceleration limited motion) has reached the user setpoint value and other conditions are met.

Full list of conditions of this status being true are:

  • Trajectory planner output is stationary (for more info, see signal path of motor drive)
  • and, following status bits are false:
    • Follow error recovery
    • Homing
    • Fault stop
    • Follow error warning
  • and, following status bits are true:
    • Initialized
    • Enabled
    • Run (drive active)
Enabled True when drive has enabled state on. This allows drive to control motor if no faults are active.
Run (drive active) True when drive is initializing or controlling motor. Goes false if enabled is false or faults are active
Homing active True when drive is performing homing sequence. Goes false after homing is complete or not enabled
Braking True when motor is being braked electrically and/or mechanically
Permanent stop True when drive requires restart before continuing motor control. Goes true when changing certain parameters or if initialization fails Restart drive to see if the state clears. If not, check parameterization and usage errors.
Voltages good True when HV DC bus voltage is withing configured range (from Under voltage fault thresholdFUV to Over voltage fault thresholdFOV)
Fault stopped True when drive is disabled true to active fault state Perform clear drive faults function (from Connect tab). If problem repeats, check motor & tuning parameters and operating conditions. See fault register and fault location for hints.
Ready for use a.k.a servo ready True when drive has performed all initializations, possible homing and is enabled and running. When true, drive is ready to follow user setpoint commands. The full logic of this bit is:
  • Statuses Run and Initialized are both true
  • Statuses Follow error recovery and Homing are both false
  • If homing has been enabled (Homing enabledHME is not Disabled), then homing has completed successfully (i.e. not failed or aborted)
  • Drive power stage is operational (there is small, typicall5y <0.2 second, initialization delay from rise of Enable/Clear faults signal to have power stage operational)
STO active True when safe torque off is active. In Argon this monitors only STO2.

Fault bits register[edit | edit source]

Name Description Troubleshooting Filter time before activation1
Tracking error Drive stopped due to position or velocity tracking error getting larger than configured limit (Position tracking error thresholdFPT or Velocity tracking error thresholdFVT) Check settings, operating conditions and fault limits to resolve. Goal faults filter timeFFT
Over velocity Motor has exceeded the speed limit defined at Over speed faultFEV Goal faults filter timeFFT
Hardware Drive internal error has occurred Possibly external interference (check wiring and EMI suppression) and stability of logic supply voltage. If problem stays, contact Granite Devices support. None
Over temperature Drive temperature has exceeded its maximum value None
Feedback Failure in feedback device has been detected None
Over current Measured current was exceeding the limit value (current spike) Check wiring or try different Over current toleranceFOC value Affected by Over current toleranceFOC
Internal comm error Drive internal error has occurred Possibly external interference (check wiring and EMI suppression) and stability of logic supply voltage. If problem stays, contact Granite Devices support. None
Power stage forced off True when some of the fault states is forcing power stage off to protect drive. Motor is freely spinning unless braked mechanically. None
Under voltage HV DC bus voltage below Under voltage fault thresholdFUV value Check voltage, parameters and safe torque off None
Over voltage HV DC bus voltage above Over voltage fault thresholdFOV value Check voltage and Over voltage fault thresholdFOV. If happens during motor deceleration, then a braking resistor is needed. None
Motion range Motor has been commanded outside the allowed travel boundary. I.e. driven to limit switch when Limit switch functionLFS is set to fault stop None
Firmware error Drive internal error has occurred Possibly external interference (check wiring and EMI suppression) and stability of logic supply voltage. If problem stays, contact Granite Devices support. None
Init Initialization failed. Possible reasons: drive disabled or faulted during initialization or initialization time-outed Check enable signal, parameters, wiring and faults None
Motion Motor stall or loss of feedback signal detected Adjust Motion fault thresholdFMO to larger value or disable Goal faults filter timeFFT
SimpleMotion SimpleMotion V2 Communication error detected, possibly connection lost, invalid parameter value is sent or transfer error caused by EMI or bad wiring None
Configuration Fault caused by invalid or unstable configuration parameters Refer to Fault location number for pin-pointing the fault source None
Fault location ID See Fault location

1) The time duration that drive will allow fault condition be true before fault status is latched. Some faults have user adjustable time delay to reduce error sensitivity in dynamic conditions, such as rapid acceleration.


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