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Resolution of the PEM2 Leap Year Transition

An unexpected but solvable issue has been discovered with the PEM2’s handling of the leap year transition. On or after the last day of the leap year (12-31-08), when uploading data from the PEM2, an error message appears showing the number 4 and the PEM2 Wrench Icon, Wrench icon on the display. This issue is easily rectified, and data prior to 12-31-08 will not be lost or compromised in any way.

Note: A gap in data collection from 12-31-08 until the monitor is reset will exist. Prompt resetting will minimize any impact in long-term data analysis.

Resolving the PEM2 leap year transition includes the following steps:

  1. Restoring the PEM2's data files
  2. Fixing the PEM2's data files
  3. Resetting the PEM2 device

Follow the steps below to resolve the PEM2 leap year transition.

Notes:

For a list of Frequently Asked Questions on this topic, see our PEM2 Leap Year Transition FAQ page.

1. Restore the PEM2's Data Files


To restore the data files of the PEM2, follow the instructions below. This step must be performed using a Windows based computer.

  1. Locate a blank USB flash drive.
  2. Insert the USB flash drive into the PEM2 device in order to retrieve the data. The number 4 and PEM2 Wrench Icon, Wrench icon appear on the PEM2's display once the data is downloaded onto the USB flash drive.

    Note: The number 4 displays for only a few seconds. The PEM2 Wrench Icon, Wrench icon, on the other hand, remains on the PEM2 display until the USB flash drive is removed from the device.

  3. Remove the USB flash drive from the PEM2 device once the error message and the icon display. The PEM2 will resume normal operation after the USB flash drive is removed.
  4. Repeat steps 2 and 3 until the data is retrieved from all of your PEM2s.
  5. Insert the USB flash drive into the USB port of a Windows based computer.

    Important: DO NOT perform any operations on the retrieved file, such as copy. The correction must be performed on the USB flash drive.

  6. Open the My Computer dialog:

    My Computer Dialog

  7. Right click on drive letter of the USB flash drive and select Properties. The Properties dialog displays.
  8. Select the Tools tab:

    Properties Dialog

  9. From the Error-checking section, click Check Now. The Check Disk dialog displays.
  10. Check the Automatically fix file system errors checkbox:

    Check Disk Dialog

  11. Click Start. Once completed, the Disk Check Complete message displays:

    Check Disk Complete Message

  12. Click OK. The Disk Check Complete dialog closes.
  13. Click OK to close the Properties dialog. The data files are now restored and are ready to be fixed.


2. Fix the PEM2 Data Files


Once the data files are restored, the individual PEM2 data files must be fixed. To fix the PEM2 data files:

  1. Open the My Computer dialog.
  2. From the My Computer dialog, view the contents of the USB flash drive.
  3. Open the PEM2 file in Notepad (PC) or TextEdit (Macintosh):

    1. Right click on the PEM2 file.
    2. Select Open With and click Notepad (PC) or TextEdit (Mac). The file opens.

  4. Scroll to the bottom of the file and verify if any data points were created after 12-30-2008, as represented below:

    Data File with Errors in Notepad

    • If the data file does contain data points that were created after 12-30-2008, carefully delete all the rows that occur after 12-30-2008.
    • If the file does not contain data points that were created after 12-30-2008, proceed to step 5.

  5. Place your cursor to the right of the last character and press Enter. The cursor must be on the left and below the last line of data, as indicated below:

    Data File in Notepad

  6. Save the corrected file in a location other than the USB flash drive:

    Important: You must save the corrected file in a permanent location, because the data will be deleted from the PEM2 device. This file will be your only backup record of your data prior to 12-30-2008.

    1. Click File | Save As. The Save As dialog displays.
    2. From the Save in drop down, select the location where you want to save the file.
    3. Click Save. The file is now saved and ready for use.

  7. Repeat steps 3 to 6 for each PEM2 data file.
  8. Upload all the corrected files to PEMdata.com to ensure that they are fixed and viable:

    1. Click on the following link to launch the PEMdata website: PEMdata.com.
    2. From the left navigation bar, select Guest User.
    3. From the Upload a Dataset section, click Browse. The Browse for File (PC)/File Upload (Mac) dialog displays.
    4. Browse to the corrected files located on your computer (not on the USB flash drive) and select the first file.
    5. Click Open. The file path displays in the File 1 text field.
    6. Click Upload. The Conditions of Use page displays.
    7. Click the I agree with the PEMdata conditions of use checkbox.
    8. Click Submit. The data displays as a graph.
    9. Repeat steps b to h to upload the rest of your PEM2 data files.
Once all the data files are fixed, the PEM2 device is ready to be reset.



3. Reset the PEM2 Device


Important: Resetting the PEM2 device should be done only after it has been determined that the past history data file has been properly recovered, cleaned, and saved.

When the PEM2 device is reset, all the data will be cleared. This will remove the problematic time stamp of the 2008 leap year. New data collection will start immediately on the date the PEM2 is reset.

To reset the PEM2 device:

  1. Insert your USB flash drive into the USB drive of your computer.
  2. Download the command file that allows you to reset the device:

    1. Click on the following Zip file: pem2command.zip. The File Download dialog displays.
    2. Click Save. The Save As dialog displays.
    3. Select a location such as the desktop to save the file and click Save. The Download Complete dialog displays.
    4. Click Open. The Zip file dialog displays.
    5. Copy and paste the command file (command.pm2) to your USB flash drive. The command file is now saved on your USB flash drive.
    6. Safely remove the USB flash drive from the computer's USB drive.

  3. Insert the USB flash drive into the PEM2 device. The command runs and clears all the data. All the available icons blink on the display for about 15 seconds.
  4. Once the hourglass icon stops blinking, remove the USB flash drive from the PEM2 device. The temperature and RH (or the number 2.5, which is the firmware version) appear on the display. The PEM2 device is now reset and normal data collection will resume.
  5. Repeat step 3 and 4 for each remaining PEM2 device.
  6. Once all the PEM2 devices have been reset, delete the command file from the USB flash drive.

    Important: The command file is a universal command file that will apply to any PEM2 device. To avoid accidentally clearing your PEM2 device in the future, ensure that the command file is deleted from the USB flash drive.
Note: The leap year transition problem will reoccur in the leap year 2012. Reprogramming the PEM2 is required to permanently fix the issue, and will be handled when your PEM2 is returned to IPI for standard recalibration (recommended every 3 years). If your PEM2 device is not recalibrated before 12/31/2012, IPI will send a reminder to clear and reset the PEM2 device to prevent any interruption in data collection.