Links to the HART Protocol Specifications are available via our main website, visit http://go.fieldcommgroup.org/HART 


HART Protocol Specification Release 7.07 - July 2020
Updates include:
  • Token Passing Data-Link Layer Specification (HCF_SPEC-081, FCG PS20081, Revision 9.1) is a minor revision consisting solely of clarifications and corrections.  In addition, the document format was updated to align with FieldComm Group standards. 
       

  • Network Management Specification (HCF_SPEC-085, FCG PS20085, Revision 3.0) includes significant improvements to HART-IP Specifications.  These improvements were the result of HART-IP experience garnered over the last 10 years.  
     
    Ambiguities identified by developers and during Test Specification development were clarified/resolved.  Minimum and maximum values were added to improve the specifications for Network Layer constants and attributes. 
     
    In addition, a new message type ("Direct") was added to HART-IP. Since this is a new feature, the addition requires a major revision to the Network Management Specification. Other new requirements include HART-IP Server support for 3 clients and support for NTP/PTP. 
       

  • Command Summary Specification (HCF_SPEC-099, FCG PS20099, Revision 10.1) is a minor revision consisting solely of clarifications and corrections. Clarification to the application of Process Data Quality and Limit Status; and command autonomy requirements are included. 
       

  • Universal Command Specification (HCF_SPEC-127, FCG PS20127, Revision 7.2) incorporates the addenda from 2008 and the comments, improvements and clarifications submitted by the HART-community since 2008. The interaction between Command 48 and the More Status Available bit has generated many questions over the years.  Consequently, this has been clarified in the revision. In addition, the document format was updated to align with FieldComm Group standards. 
       

  • Common Practice Command Specification (HCF_SPEC-151, FCG PS20151, Revision 12.0) is a major revision since 4 new commands have been added.  The most significant new commands add support for Time-To-Apply Actions.  
     
    In addition, the specification has been improved to incorporate many clarifications and corrections based on developer experience.  Clarifications and corrections include those to HART-IP requirements, condensed status and a number of Response Codes. 
       

  • Block Data Transfer Specification (HCF_SPEC-190, FCG PS20190, Revision 1.1) was added to the HART Protocol with HART 6 in 2001.  This minor revision consists solely of clarifications and corrections primarily related to opening and closing a block transfer connection.  In addition, the document format was updated to align with FieldComm Group standards. 


HART Protocol Specification Release 7.06 - June 2016


Updates include:
  • Improvements to the 2.4GHz DSSS O-QPSK Physical Layer and TDMA Data-Link Layer are entirely clarifications and corrections.
  • The FSK Physical Layer was enhanced to add simplified requirements for Maintenance Ports. Maintenance Ports must be only used as a temporary, short-range connection enabling initial commissioning or trouble-shooting the Field Device. This revision also includes pertinent clarifications and corrections.
  • The Command Summary was improved to include guidance on data caching, Command Aggregation, and identification of device capabilities. Clarifications and enhancements to Field Device Revision (forward compatibility rules) we also made.
  • Clarifications and Corrections (especially to Condensed Status and Event Notification) were made throughout the Common Practice Command. In addition, commands were added to support Client Subscriptions (change notification).
  • Common Tables has been updated to add new Manufacturer ID, Expanded Device Type Codes and other tables (e.g., Unit Codes) as needed. For routine maintenance (like performed in this revision) the Common Tables are administratively updated with the consensus of the HART Technology Working Group (WG).

For more information see the relevant specifications.
HART Protocol Specification Release 7.5 - May 2013


Updates include:
  • Common Tables has been updated to add new Manufacturer ID, Expanded Device Type Codes and other tables (e.g., Unit Codes) as needed.
HART Protocol Specification Release 7.02 - March 2009



Updates include:
  • HART Protocol Revision 7.1 includes all changes, clarifications and corrections resolved during the process with corrections and clarifications documented in Addendums to each of the following specifications:
• TDMA Data-Link Layer Specification (HCF_SPEC-075)• Network Management Specification (HCF_SPEC-085)
• Universal Command Specification (HCF_SPEC-127)
• Common Practice Command Specification (HCF_SPEC-151)
• Wireless Command Specification (HCF_SPEC-155)
• Wireless Devices Specification (HCF_SPEC-290)


  • Common Tables has been updated to add new Manufacturer ID, Expanded Device Type Codes and other tables (e.g., Unit Codes) as needed.

For more information see the relevant specifications.
HART Protocol Specification Release 6.05 - January 2007
Updates include:

The HART Protocol Revision 6 supports the increasing functionality of HART communicating devices in the following ways:
  • Expansion of unit codes by classifying Device Variables according to function.
  • Modification of specification language for application to devices other than transmitters.
  • Addition of transducer trim commands to the Common Practice Command Specification in order to allow the linear trim of Device Variables.
  • Expansion of polling addresses for support of loop current at polling addresses other than 0.
  • Inclusion of delayed response mechanism to allow devices more time to perform calculations before responding to a request. 
  • Responding to end-user request for longer tags by adding Universal Command support for 32-byte device tags.
  • Addition of Common Practice commands to write Device Variables, lock instrument panels,physically identify addressed devices, capture digital data from a device as input data for use in the calculations of another device, find devices and read Device Variable status.
  • Incorporation of Device Variable Classification codes for use in classifying devices according to related functions and assigning units codes to common Device Variables for each class.
  • Addition of Device Families to allow the commissioning and parameterization of Field Devices based on the process connection they support.
  • Completion of the block transfer mechanism introduced in HART Revision 5. This mechanism establishes the transfer of a data stream between a hosts and slave devices.

For more information see the relevant specifications.
HART Protocol Specification Release 5
HART 5 is no longer used for new product development. 


Note: HCF_SPEC-013 (FCG TS20013) Annex A contains a history of change summaries for each prior release of the Protocol Specifications.