VxWorks Targets Do Not Honor New Daylight Savings Time RulesPrimary Software: LabVIEW Modules>>LabVIEW Real-Time ModulePrimary Software Version: 8.2.1 Primary Software Fixed Version: N/A Secondary Software: LabWindows/CVI Add-ons>>LabVIEW/CVI Real-Time Module Hardware: CompactRIO>>Controllers>>cRIO-9012
Problem: Recently, the rules for Daylight Savings Time start and stop have changed. My VxWorks-based controller (such as the cRIO 901x series) seems to be an hour off sometimes. How do I correct this? Solution: Please consult the LabVIEW Real-Time Module 8.6 Readme. As of version 8.5, VxWorks targets do not comply with the latest rules for Daylight Savings Time. As a result, VxWorks targets may report incorrect time from early March through early April and from late October through early November. The actual start and end dates of Daylight Savings Time differ from year to year, and not all regions participate in Daylight Savings Time. Refer to the official Daylight Savings Time regulations in your region for more information. There are a couple of options for getting around this issue. The attached folder contains some VIs that can be used to check if the controller is in DST or not. Use DST_Rule.vi to set the dates and times when DST is in affect. This VI will save the information to a configuration file stored on the RT target. In your real-time program, use isDST.vi to determine whether the controller is in DST or not. If the controller is in DST you can manually correct the time value. The attached VIs are saved in LabVIEW 8.2 Another workaround is to use the RT Set Date and Time VI from the Real-Time utilities palette. Using this VI to periodically synchronize the RT time with a local time server is an easy way to get the correct time. Refer to the Related Links section below for example programs on getting and setting the system time on a Real-Time target. Related Links: Developer Zone Example: Getting/Setting the System Date/Time on CVS, PXI RT Targets Developer Zone Example: Set Date and Time on PC, PXI, and PXI-RT Using Network Time Protocol (NTP) Server from NIST LabVIEW Real-Time Module 8.6 Readme What Operating System is my Real-Time Controller Running and Why? Attachments:  DST_Correction.zip
Report Date: 07/16/2007 Last Updated: 07/09/2009 Document ID: 4BFDL3XL |
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