Why is my Rack Automatic Transfer Switch inaccessible after a firmware upgrade?


29 September 2021


My Rack Automatic Transfer Switch (ATS) inaccessible over the network after a recent firmware upgrade.

Product Line
  • Rack ATS models:
    • AP7750
    • AP7722
    • AP7701
    • AP7751
Note: These models can be quickly identified by their UPS-like SmartSlot - their Network Management card is removable.

  • All serial numbers
  • All firmware revisions
  • Firmware upgrade recently completed


APC has (2) current generations of Rack ATS products that use two different firmware revisions. If the incorrect version is flashed to the aforementioned models, this situation can occur.

The first generation includes the following SKUs:
  • AP7750
  • AP7722
  • AP7701
  • AP7751
Note: These models can be quickly identified by their UPS-like SmartSlot - their Network Management card is removable.
The second generation ATS's are all AP77XX SKUs except the ones list above. They are easily identified by their unique LCD display and built-in network jack.

Each generation has its own firmware revision:
  • Gen 1 - 2.6.1
  • Gen 2 - 3.X.X


Check the APC Software / Firmware site for the latest Gen 2 firmware.

Gen 1 units CANNOT be flashed the 3.X.X firmware. If they are, the network card will go into a endless reboot cycle as it attempts to load the incorrect application version. However, the network card is accessible on the network for a short period of time (roughly 10 seconds) before each reboot. It is during this time that the card can be flashed back to the correct version using the upgrade utility wizard. Follow these steps:
  • Download the 2.6.1 firmware executable
  • Run the self extracting exe file
  • The upgrd_util.exe file will start automatically. Enter the IP address, username, and password of the ATS when prompted
  • Do NOT confirm these settings yet (do not enter 1)
  • Open a command prompt or terminal interface
  • Type the following: ping<space>-t<space><IP Address> (substitute the ATS IP address) This command will ping the IP address indefinitely. You will notice that the ping will time out most of the time, however it pings successfully every few minutes.
  • When the ATS replies (successfully pings), quickly return back to the upgrd_util.exe and press 1 and enter. The wizard will start flashing the card over the network.

* Pressing Control + C will stop the ping command