Our Brands

Search FAQs

UPS Interface Expander 2 SmartSlot Card (AP9624) - Incorrect System Behavior for Some Master Server Control Functions


In certain situations, the UPS restarts immediately after turning off rather than performing the commanded function from the master server or from the UPS's LCD.

Product Line
  • UPS Device Management
    • AP9624 UPS Interface Expander 2

  • All serial numbers
  • UPS types with outlet groups


For SMT, SMX, and SRT UPS model types, the UPS is monitored by the Interface Expander 2 to determine if a 'shutdown' is pending. Shutdown here refers to any pending off action such as off and stay off, shutdown (where AC input is required to turn back on), or sleep (turn off for a defined period of time). These shutdowns can occur from the serial (RJ-45) port, the USB port or from the UPS's LCD.

If a shutdown is commanded from the master server (via serial or USB connection) or from the LCD in these systems, the Interface Expander 2 and UPS may interact in such a way that the original command is overridden.  The clients are all signaled to shutdown with the proper delays but the UPS may restart immediately (as long as valid input voltage is present) after turning off instead of the intended operation such as 'off and stay off' or 'sleep.'

This issue does not affect the Interface Expander 2 and UPS shutdown (turn off until valid input voltage is present) for all on battery situations.

Note that the mode of the Interface Expander 2 (Confirmed or Timer) has no effect on this behavior.


Update: This issue has been fixed in the UPS firmware versions outlined below. For additional information and details, please refer to knowledge base article ID FA164737.
UPS Model Firmware Fix Version
SMT Tower (firmware UPS 08.0 or greater)UPS 09.3
SMT 2U RackmountUPS 09.3
SMT 1U Rackmount (follow "SMX 1500VA or less" firmware)UPS 09.8
SMX 1500VA or less (firmware greater than UPS 05.0)UPS 09.8
SMX Larger than 1500 VA (firmware between UPS 05.0 - UPS 07.0)UPS 06.6

Original Resolution content: There is no practical work around to this issue at this time. This issue can only be avoided by not controlling the system as described above which limits the system's functionality. In order to resolve this issue, newer versions of UPS firmware will be required.

APC Philippines

Users group

Discuss this topic with experts

Visit our Community for first-hand insights from experts and peers on this topic and more.