FieldComm Group manages two lists for standardized Unit Codes. If the Unit Codes currently published in the Technical Specifications for Foundation Fieldbus or HART does not contain a code you need to use, please follow the instructions below to obtain a new Unit Code.

Please note the following before sending a request for a Unit Code:

For HART Protocol devices, unit codes 240-249 are available for the manufacturer to create their own unit codes. The general rule for unit codes is that if it is something that the general industry may need as a standard, then submit a request to add it to the Common Tables specification. If the unit code is unique to your company, then it is recommended to use the 240-249 unit code range with the Classification set to an appropriate value from Common Tables, 5.21 Table 21. Device Variable Classification Codes. See more about reserved unit codes here.

For FOUNDATION Fieldbus devices, unit codes can be requested via support ticket. Once approved, the code will be added to the next release of Tech Note 16 (TN-016).

How to submit a request:

Please open a support ticket and specify the following:

  • I need assistance with:  General Technical Support
  • Details: select the applicable technology/protocol 
  • Subject: New Unit Code 
  • Description: Include answers to all of the following questions:
    • Unit Name (abbreviation)
    • Unit Name (expanded)
      • English text (required)
      • German Translation (required)
      • Other languages (optional)
    • SI Unit (Yes or No) (required) 
      • If SI Unit, provide conversion factor to base SI Unit code being requested
    • Reasons for this request (required) 
      • Industry Use
      • Standard Organization or Document Reference (include a URL or attach a document to the ticket) 
      • Specific Technology Application

Incomplete requests will not be processed.

The requester will be informed if the code will be assigned and what the value will be. If a code already exists (but is pending publication) for the requested Unit Name, that information will be returned to the requester.