2020 Mercury-Security LP Leap Day Issue


It was recently discovered that LP intelligent controllers will not properly handle leap year time calculations. After February 29th, 2020, Leap Day, the intelligent controller will report time and date incorrectly. This will have unknown effects on the functionality of Access It! Universal.NET.

Identifying LP Panels

The easiest way to distinguish if a LP panel is being used is to physically look at the panel. LP panels are red, while EP panels are traditionally green. 


LP intelligent controllers that are deployed in “legacy” mode are not affected. Additionally, EP series controllers, bridge products (M5, MS, and MI) and legacy controllers such as the SCP series are not impacted by this issue. 

Customer Actions

All LP panels must be upgraded to firmware minimum 1.278. These files are obtainable via the download link below and detailed instruction on how to upgrade firmware can be found in the Updating LP / EP Firmware article.


There are no workarounds.

Firmware Download

The following link contains LP firmware files for LP-1501, LP-1502, and LP-2500 models: LP 1.292 Firmware.

The following link contains LP firmware files for the LP-4502 model: LP-4502 1.290 Firmware.
This download will be a zip file and the firmware files will need to be extracted to C:\Program Files (x86)\RS2 Technologies\Access It! Universal.NET.


  1. Q: What happened to the 1.278 firmware download link?
    A: In order to mitigate the following potential issue, RS2 has chosen to use this newest 1.292 firmware.
    Mercury-Security announced that after upgrading to 1.278 for the leap year fix, MR51e and/or MR62e SIOs may not come back online. However, the probability of this is likely rare as all of the following conditions need to be true:
    1. LP board at the headend 
    2. More than one MR51e and/or MR62e boards are installed downstream (via Ethernet)
    3. MR51e/62e are configured to obtain an IP from DHCP (not static)
    4. The IP address that is received is a public IP (not private)

  2. Q: What is the definition of Legacy Mode?
    A: Legacy mode pertains to LP panels that are powered up with dip switch 4 on. This was required in order to support panels on software revisions that did not include LP models.
    More on this can be found in the article LP Series Legacy Mode.
  3. Q: When will panels with the new 1.278 firmware begin to ship?
    A: Any LP panel shipped after 1/14/2020 will have minimum firmware 1.278 installed.
  4. Q: What will happen on leap day with non-patched panels?
    A: Testing indicates that as the LP panel reaches 12:00 AM GMT on 3/1/2020 it will revert back to 12:00 AM 2/29/2020 and the cycle will continue. This will forever leave the panel acting as if it was 2/29/2020. In some test cases, the clock began to move backwards in time.
  5. Q: What if I have an LP-4502 with firmware 1.281?
    A: LP-4502 panels with 1.281 are still impacted by this issue and must be upgraded to the LP-4502 1.290 Firmware.

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  • 10-Jun-2020