How to Set the Time Zone of a Real-Time Controller

This article explains the steps to follow to configure a Real-Time controller's time zone and include three different approaches to change the timezone depending on the application and the developer implementations and interests. 

After following the steps listed in this document, you should be able to configure your current time zone and get the correct time stamps in graphs, data structures, data logs, among others. 

By default, the Real-Time controller is set to Coordinated Universal Time (UTC). You can configure the time zone using one of the following methods:

1. Using Measurement & Automation Explorer (MAX).
2. Modifying the INI file.
3. Using NI System Configuration APIs.

Measurement & Automation Explorer:

Select the desired time zone in Measurement & Automation Explorer (MAX) on the Time Settings tab of the Real-Time target.

 

Modifying the INI File (for VxWorks or Phar Lap ETS Real-Time Targets only):

The following method is limited to Phar Lab & VxWorks based targets. If your device is running NI Linux RT, please follow the steps listed in this article, if not please continue.

The time zone of a Real-Time controller can also be changed by modifying the RTTarget.TimeZone token in the ni-rt.ini. The token can be found in the [LVRT] section of the ni-rt.ini file. 

1. Use WebDAV or FTP to copy the ni-rt.ini file from the Real-Time controller to the development computer.
2. Open the ni-rt.ini file in a text editor (for example Notepad).
3. At the top of the file, there is a section named [LVRT] which is where the RTTarget.TimeZone token may be found or added.
4. To change the time zone either add or modify the RTTarget.TimeZone token to the INI file.
   • For example, use INI token RTTarget.TimeZone=CST6CDT to set the controller to the Central United States time zone. Available INI values are listed in the table below.
      

     INI Value	Time Zone	UTC Offset
     CUT0GDT	Coordinated Universal Time	UTC
     GMT0BST	United Kingdom	UTC
     AZOREST1AZOREDT	Azores, Cape Verde	UTC-1
     FALKST2FALKDT	Falkland Islands	UTC-2
     GRNLNDST3GRNLNDDT	Greenland, East Brazil	UTC-3
     AST4ADT	Central Brazil	UTC-4
     EST5EDT	Eastern United States, Colombia	UTC-5
     CST6CDT	Central United States, Honduras	UTC-6
     MST7MDT	Mountain United States	UTC-7
     PST8PDT	Pacific United States, Yukon	UTC-8
     AST9ADT	Alaska	UTC-9
     HST10HDT	Hawaii, Aleutian Islands	UTC-10
     BST11BDT	Bering Strait	UTC-11
     NZST-12NZDT	New Zealand	UTC+12
     MET-11METDT	Solomon Islands	UTC+11
     EET-10EETDT	Eastern Australia	UTC+10
     JST-9JSTDT	Japan	UTC+9
     KORST-9KORDT	Korea	UTC+9
     WAUST-8WAUDT	Western Australia	UTC+8
     TAIST-8TAIDT	Taiwan	UTC+8
     THAIST-7THAIDT	Thailand	UTC+7
     TASHST-6TASHDT	Central Asia	UTC+6
     PAKST-5PAKDT	Pakistan	UTC+5
     WST-4WDT	Gorki, Central Asia, Oman	UTC+4
     MEST-3MEDT	Turkey	UTC+3
     SAUST-3SAUDT	Saudi Arabia	UTC+3
     WET-2WET	Finland	UTC+2
     USAST-2USADT	South Africa	UTC+2
     NFT-1DFT	Norway	UTC+1

5. Save the file as ni-rt.ini locally (such as the desktop). Be sure the file is named ni-rt.ini.
6. Use WebDAV or FTP to transfer the file back to the Real-Time controller.
7. Reboot the Real-Time controller.

Note: Linux Real-Time targets support the tz (or Olson) database. The database contains all the needed information about DST settings for specific time zones. The RTTarget.DSTRule INI token cannot be changed to alter DST rules on Linux RT targets.

NI System Configuration APIs:

LabVIEW 2012 Real-Time Module and later:
The LabVIEW 2012 Real-Time Module introduced the NI System Configuration API, which can be used to programmatically set the time zone of a Real-Time Controller using the Set Time VI.

The input timezone string for the Set Time VI needs to be of the form Etc/GMT-X where positive values for X represent hours west of the GMT. For example, Etc\GMT+6 is the equivalent to Central Standard Time in the US. Valid values range from 12 to -13 centered around GMT. For more information on how to set time zones see the Set Time (VI) help. 

Note: This image is a LabVIEW snippet, which includes LabVIEW code that you can reuse in your project. To use a snippet, right-click the image, save it to your computer, and drag the file onto your LabVIEW diagram.

If the above code snippet is executed on the Real-Time target, the Target parameter must have a value of localhost. Otherwise, error -2147467263 will be thrown (NI System Configuration: This operation is not implemented for this target or resource).

LabVIEW 2011 Real-Time Module and Previous:
The LabVIEW 2011 Real-Time Module and previous Real-Time Modules do not include support for setting a specific time zone. Instead, it is recommended to set time programmatically using the RT Set Date and Time VI.

Note: VxWorks and Pharlap targets must be restarted for the time zone settings to apply. NI Linux Real-Time targets do not require a restart. Configuring the time zone also activates the daylight saving feature of the controller.