APR Recovery Scenarios

The following tables provide detailed information on when the APR feature recovers absolute position. Consider these assumptions. In each of these cases, the APR feature restores absolute position and preserves the state of the Axis Homed bit, indicating that the axis has a machine referenced absolute position.
  • All relevant axes are CIP axes.
  • Yes, machine reference is recovered (for Axes that have been homed).
  • No, machine reference is not recovered (for Axes that have been homed).
    Scenario
    Event
    Machine Reference Retained
    Controller
    Battery
    (1)
    Yes
    Controller Power Cycle with Battery
    Yes
    Controller Removal/Insertion Under Power (RIUP) with Battery
    (1)
    Yes
    Controller Firmware Update
    Yes
    Controller update from Secure Digital card
    Yes
    Swap two controllers with the same catalog numbers (Secure Digital card also swapped). 
    It is only possible to restore the APR from a Secure Digital card if the second controller had a previously homed application.
    Yes
    1. Axes are homed.
    2. Project is saved to Secure Digital card.
    3. Axes are moved and re-referenced.
    4. System is restored from Secure Digital card.
    The system absolute position is restored to re-referenced positions and the Home bit remains set.
    Yes
    The system absolute position on each machine becomes restored correctly at its respective position and the Home bit remains set.
    Yes
    Change Controller (SD card not swapped)
    No
    (2)
    Change Controller without a Secure Digital card.
    No
    Controller CompactFlash Update
    Yes
    Controller Swap (Same CF Card)
    Yes
    Change controller
    No
    Change Controller without a CompactFlash Card
    No
    Controller Power Cycle without Battery
    (1)
    No
    (3)
    Controller Removal/Insertion Under Power (RIUP) without Battery
    (1)
    No
    Take the controllers out of two systems with a battery or energy storage module and swap controller. There are no CompactFlash or Secure Digital cards on either controller.
    No
    1. Controller remains powered.
    2. Power cycle drives.
    3. Change feedback device but not motor.
    No
    Axes are homed.
    The system absolute position is lost, the axes must be rehomed, and the Home bit is cleared.
    No
    (3)
    Controller Power Cycle or Removal and Insertion Under Power without a battery or energy storage module.
    No
    Controller and drives remained powered.
    Hardware feedback failure on an axis.
    No
    Battery Backed Controller
    User program running with an axis that is not homed.
    No
    Controller and drives remained powered
    Disconnect and reconnect the Ethernet cable.
    Yes
    Disconnect and reconnect the same feedback or motor cable on an axis.
    Yes
    Inhibit or Uninhibit an axis or drive.
    Yes
    Battery Backed Controller
    Save to a Secure Digital card
    (2)
     with a homed axis and you initiate the restore.
    Yes
    RIUP controller.
    Yes
    Cycle power-on controller.
    Yes
    Cycle power-on controller that is configured to restore the user program from a Secure Digital card on power-up.
    Yes
    RAM memory becomes corrupt, and the user program is restored from the Secure Digital card.
    The machine must be referenced again because RAM memory is corrupt. There is no way to retrieve the machine reference positions from a memory card after machine memory becomes corrupt.
    No
    (3)
    User program running with a homed axis and you manually restore the user program from a Secure Digital card.
    If you reset the machine reference by using MAH or MRP after storing the user program to a memory card, the MAH and MRP changes are not lost. The APR is not restored to the reference stored on the memory card. The APR is restored to the reference stored in RAM.
    Yes
    Battery Backed Controller: Restore by taking the Secure Digital card to another controller.
    If the other controller has the same Axis ID and scaling constants as the Secure Digital card and has homed axes, the APR is not restored to the reference stored on the card. The APR is restored to the reference stored in RAM.
    The Axis ID attribute is automatically generated when you create an axis in the Logix Designer application.
    See the Axis ID attribute description in the Integrated Motion on the EtherNet/IP network Reference Manual, publication MOTION-RM003 for more information.
    Yes
    Change controller
    Transfer the Secure Digital card from the first controller to the second with the following preconditions:
    • Empty the second controller. There is no user program in the second controller.
    • The user program has been saved on a Secure Digital card with CIP Motion axes homed.
    No
    Transfer the Secure Digital Card from the first controller to the second with the following preconditions:
    • The second controller has the same user program with the controller being swapped.
    • The second Controller has axes homed.
    Yes
    Same controller
    Reload the same user program from a Secure Digital card. This scenario assumes that the axis is homed in RAM before reload.
    Yes
    Update controller firmware from Secure Digital card.
    Yes
    Controller remains powered or power cycled with battery and power cycle drives
    Change drive with same or different catalog number.
    Yes
    Change motor but not feedback device.
    Yes
    Download the same program with no hardware changes
    Change the name of the axis.
    Yes
    Download the same
    Studio 5000 Logix Designer
     to the controller.
    Yes
    Save As with a different file name.
    Yes
    Partial Export and then import an axis.
    Yes
    Added application logic.
    Yes
    Download the
    Studio 5000 Logix Designer
     project of an existing axis.
    Yes
    Add an axis.
    No for the new axis
    Copy or cut and paste or drag and then drop axis into the same project or another project.
    No for the new or pasted axis
    Export and then import into the same or another project.
    Save the project as an .ACD file to recover the absolute position.
    No
    There are changes to the axis scaling attributes.
    No
    Position feedback
    The position feedback device was disconnected or reconnected.
    Yes
    Feedback device
    The position feedback device was disconnected or reconnected.
    Yes
    The feedback device changed.
    No
    (3)
    The position feedback device was swapped.
    No
    (3)
    The position feedback device failed.
    No
    (3)
    The position feedback polarity changed.
    No
    (3)
    The Feedback mode changed.
    No
    (3)
    Restore
    Restore from Secure Digital card. (It is only possible to restore the APR from a Secure Digital card if the controller had a previously homed application.)
    Yes
    Inhibit or uninhibit
    Inhibit or uninhibit an axis.
    Yes
    Inhibit or uninhibit an I/O module.
    Yes
    Studio 5000 Logix Designer
     project
    Import or export the project download.
    Yes
    Download the project download of a new or copied axis.
    No
    (4)
    Drive
    The drive cycled power with incremental feedback.
    No
    The drive firmware updated with incremental feedback.
    No
    Change the drive
    Yes
    Cycle power to the drive
    Yes
    Cycle power to the drive with absolute feedback.
    Yes
    Change the motor if the motor does not contain a feedback device.
    Yes
    The drive firmware was update with absolute feedback.
    Yes
    The drive was disconnected or reconnected.
    Yes
    The drive was inhibited or uninhibited.
    Yes
    The drive was swapped with the same feedback.
    Yes
    Scaling
    Scaling signature has changed.
    The scaling signature changed. This change includes Transmission, Linear Actuator, Motion Resolution, and Motion Unit attribute changes.
    No
    (3)
    (1)
    The term Battery in this table assumes the ControlLogix 5560 or GuardLogix 5560 controller with a battery or a ControlLogix 5570 controller and a 1756-ESMxxx Energy Storage Module. ControlLogix 5580, GuardLogix 5580, CompactLogix™ 5380, and Compact GuardLogix 5380 controllers have embedded energy storage modules.
    (2)
     The controller cannot generate the fault because the data cannot be preserved.
    (3)
     When any of these conditions occur, the Axis Homed bit, if set, is cleared indicating that axis position is no longer referenced to the machine. To flag the condition that the Axis Homed bit has been cleared and that the machine referenced absolute position has been lost, an APR Fault is generated. This fault is recoverable and can be cleared via any Fault Reset or Shutdown Reset instruction.
    (4)
     Not retained for the new or copied axis.
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