Back to top

AKD Backup FPGA Notice

This notice is to inform AKD owners about a bug in the Backup FPGA firmware. This page provides information that will help you understand and update the backup FPGA firmware to the latest version.

Notice

What is the bug?

During recent internal development activities, it was discovered that a specific sequence of events could lead to an unintentional motor holding brake release due to corrupted firmware.

The condition may occur from the following sequence of events:

  1. Initiate a user firmware file download (via Workbench or Fieldbus)
  2. Interrupt the download process (for example by disconnecting the Ethernet cable)
  3. The firmware may be corrupted due to the interruption
  4. Power cycle the AKD (remove power, re-apply power)
  5. If the firmware was corrupted, the AKD will power up using the Backup FPGA firmware

If items 1-5 occur, the Motor Brake will unexpectedly disengage. The reason for this behavior is an issue in the Backup FPGA firmware.

What is the “Backup FPGA firmware”?

The Backup FPGA is programmed at factory and is not a part of the user firmware file. The Backup FPGA image is not normally loaded or used. Updating the user firmware does not touch the Backup FPGA firmware and vice versa. The Backup FPGA’s purpose is to provide a fallback mechanism to download firmware when the user firmware is corrupted. This Backup FPGA firmware supports only the minimal functionality necessary to communicate so the user can flash the AKD with a new user firmware.

What are the effects of the bug?

If the AKD must boot up with the Backup FPGA firmware due to corrupted user firmware, it is possible the AKD will energize the holding brake with 24 Volts, causing the brake to disengage (if there are no additional switches such as a safe brake relay).

If you have a gravity-sensitive load that is not properly secured, the load could begin to move uncontrollably, simply due to the kinetic energy of the load.

Is my AKD affected by the bug?

The following model numbers are affected by the bug:

  • AKD-P; AKD-B; AKD-T; AKD-M
  • KC1-B; KC1-M

NOT affected are models beginning with AKD-N, AKD-C

The following serial numbers are affected by the bug:

  • B-0901-00001 – B-1714-00255 (“-00256” and higher have the updated firmware included)
  • P-0901-00001 – P-1715-00004 (“-00004” and higher have the updated firmware included)
  • R-0901-00001 – R-1714-00221 (“-00222” and higher have the updated firmware included)
  • T-0901-00001 – T-1715-00000 (“-00001” and higher have the updated firmware included)

Is my application affected by the bug?

If you are using the affected AKDs listed above, your application may or may not be affected by this bug. Please follow this flowchart to check if this bug affects your application:

image

How do I fix it?

If your application is affected, there are several ways to mitigate risk without upgrading your firmware. Each countermeasure alone should eliminate the risk:

  1. Secure the load or move to a safe position before updating the standard AKD firmware.
    By securing the load or moving to a safe position, disengaging the brake after a failed firmware update attempt will have no effect. This is required by regulatory agencies, so you are likely doing this.
  2. Unplug the motor when updating the standard AKD firmware.
    By unplugging the motor from the AKD the brake is also disconnected. Hence it will always stay engaged
  3. Update the Backup FPGA firmware.
    We recommend that you update the Backup FPGA firmware if you cannot apply either of the above-recommended countermeasures.

Please contact your Kollmorgen Application Engineer if you have any questions this notice or KDN does not answer.

Instructions

The following steps may be taken to update the Backup FPGA on AKDs.

  1. Connect to your drive with Workbench.
  2. Select the terminal and type DRV.INFO then execute the command.
    image
    In this example the Backup FPGA version can be identified by looking for the "FPGA" section and "Resident image" alias Backup FPGA.

    The coding for the backup FPGA version is as follows: “FPB00x_yyyy_yy_yy”, where “x” represents a certain FPGA type and “y” represents the version number. The upper number represents the most significant version number. All versions lower than “0602.00.01” are affected.

    In this example the version is “0300.00.00” , which is a backup FPGA version with the brake issue.
  3. Go to the main window and click on Update.
    image
  4. Choose the correct Backup FPGA to download, which matches your drive type. Note see Backup_FPGA_v0602_00_01.zip. Click Open
  5. Workbench filters the correct type matching your drive type.

    In this example the drive type is AKD-P-00307-NBCC-0000, where the bold characters need to match the file name. Workbench filters the correct file to be AKD-P-NBCC-V0602-00-01-R-FPGA.i00.
    image
  6. Wait until Workbench has finished the download procedure.
    image
  7. Verify that the upgrade of the Backup FPGA was successful by repeating steps 2 and 3. Check that the version is 0602_00_01. If the version matches, the brake issue in the Backup FPGA is resolved.
FPGA
Version             : FP0006_0602_00_00
Operational image   : FP0006_0602_00_00
Resident image      : FPB006_0602_00_01
Size                : 45

FAQ

Why is there a Backup FPGA firmware?

The Backup FPGA’s purpose is to provide a fallback mechanism to download firmware when the user firmware is corrupted. This Backup FPGA firmware supports only the minimal functionality necessary to for the FPGA (field-programmable gate array) to communicate so the user can flash the AKD with a new user firmware.

What is the Backup FPGA Bug?

During recent internal development activities, it was discovered that a specific sequence of events could lead to an unintentional motor holding brake release due to corrupted firmware.

The condition may occur from the following sequence of events:

  1. Initiate a user firmware file download (via Workbench or Fieldbus)
  2. Interrupt the download process (for example by disconnecting the Ethernet cable)
  3. The firmware may be corrupted due to the interruption
  4. Power cycle the AKD (remove power, re-apply power)
  5. If the firmware was corrupted, the AKD will power up using the Backup FPGA firmware

If items 1-5 occur, the Motor Brake will unexpectedly disengage. The reason for this behavior is an issue in the Backup FPGA firmware.

When is the Backup FPGA firmware used?

The Backup FPGA firmware is used only when the operational FPGA firmware is corrupted. It is NOT used under normal operating conditions including firmware download and boot up.

If my system does not have a brake, am I affected by this issue?

No.

If my system is always in a safe position during a firmware download, do I need to apply further countermeasures?

If you have properly secured your system such that no motion will occur if the brake disengages during the above sequence, then you do not need to apply further countermeasures.

What are possible ways to prevent this issue?

One of the following countermeasures can prevent this issue:

  • Secure the load during firmware download
  • Remove the motor connector from the AKD before starting firmware download (remove power from the AKD before disconnecting any cables!)
  • Upgrade the Backup FPGA firmware on the AKD to version FPB0xx_0602_00_01 or higher.

What AKDs are affected?

The following model numbers are affected by the bug:

  • AKD-P; AKD-B; AKD-T; AKD-M
  • KC1-B; KC1-M

NOT affected are models beginning with AKD-N, AKD-C. 

Which serial numbers are affected?

The following serial numbers are affected by the bug:

  • B-0901-00001 – B-1714-00255
  • P-0901-00001 – P-1715-00004
  • R-0901-00001 – R-1714-00221
  • T-0901-00001 – T-1715-00000

Does the brake disengage while a firmware download is running?

No. The brake will not disengage during a firmware download.

The brake may disengage during a reboot if the download fails and the user firmware has been corrupted.

How do I update the Backup FPGA firmware on my AKD? Is this something I can do myself?

Yes, you can update the Backup FPGA firmware yourself. Instructions to upgrade the Backup FPGA firmware can be found on this page or downloaded. The downloadable file may also be found as an attachment at the bottom of this page.

What versions will this Backup FPGA upgrade apply to?

All Backup FPGA firmware versions FPB0xx_0300_00_00 through FPB0xx_0602_00_01.

0300_00_00 was released in March 2012; 0602_00_01 was released 10 April 2017.

The next question, How can I figure out the current version of my Backup FPGA firmware?, explains how to discover what version you have.

How can I figure out the current version of my Backup FPGA firmware?

Connect to the AKD. Go to terminal view. Enter the command “DRV.INFO”. In the section "FPGA", you can read the Backup FPGA firmware version.

For example:

FPGA
Version             : FP0006_0602_00_00
Operational image   : FP0006_0602_00_00
Resident image      : FPB006_0602_00_01
Size                : 45

The version for the Backup FPGA firmware can be found under "Resident image".

The coding is a follows: FPB00x_yyyy_yy_yy, where “x” represents a certain type, and “y” represents the version number. In this example the version is 0602_00_01.

If I upgrade the Backup FPGA firmware, will this influence the AKD’s behavior?

No. The Backup FPGA firmware is not used under normal operating conditions. It is not loaded and therefore not part of the main AKD functionality.

Will my firmware be tainted when updating the Backup FPGA firmware?

No. The Backup FPGA firmware is not part of the main AKD firmware and is not used under normal operating conditions.

Where was this problem found?

It was found in a Kollmorgen laboratory during product development. There are no known incidents in the field.

Can a firmware download with a standard beta or production release fix the issue?

No. The Backup FPGA firmware is not part of the standard beta or production release of operational firmware. The Backup FPGA firmware is programmed separately, and requires special files and process. The files and process are listed in this article.

Can the brake disengage unexpectedly when a firmware download was successful?

No.

If I update the Backup FPGA firmware, can the problem occur that the brake disengages after updating?

No. The updated Backup FPGA firmware (FB0xx_0602_00_01) will behave as expected.

What is the sequence of events leading to possible brake disengagement?

The sequence of events leading to possible brake disengagement is described in this flow chart. The box marked in red shows the wrong behavior due the fault condition.

image

Can you help me determine if I am affected by this Backup FPGA firmware?

The following flowchart will guide you to help determine whether you are affected by the Backup FPGA firmware. If you are, please download the new files and instructions.

image

Should I update my AKD (operational) firmware and Workbench while I am updating the Backup FPGA firmware?

Probably not. If you are an end user with an AKD working just fine in the field, we suggest you leave it alone.

If you are an OEM, and you think you might want access to the latest features, then you may want the latest (operational) firmware and Workbench. If you do decide to update the (operational) firmware and corresponding Workbench, please update your Backup FPGA firmware first. Make sure the drive accepted the updates and has the latest Backup FPGA firmware. Then, if you wish to proceed with updating the (operational) firmware and corresponding WorkBench, feel free to do so.

All of the necessary files are on KDN.

What does FPGA stand for?

Field Programmable Gate Array

Contact Information

For application-engineering assistance:

North America: +1-540-633-3545
South America: +55-11-4191-4771
Italy: +39-0362-594260
Turkey: +90-212-282-75-80
Rest of Europe: +49 (0) 2102-9394 0
India: +91-22-6188-0200
Japan: +86-400-661-2802
Mainland China: +86-400-661-2802
Hong Kong, Taiwan R.O.C. and Southeast Asia: +852-2503-6565

Ask a Question

Have more questions? Ask the community.