The Fieldbus Foundation updated its FOUNDATION fieldbus physical layer technology (H1 (31.25 kbit/s)), which is designed to improve the robustness of fieldbus control systems by optimizing device interoperability and integration. The aim of the updates is to provide easier installation, faster commissioning, and seamless startups.

Enhancements to the FOUNDATION fieldbus specifications include:

  • Addition of a test procedure for isolated couplers to the existing FOUNDATION fieldbus Coupler Test Specification. Registration of isolated couplers is now possible.

  • Improvements to the H1 Physical Layer Conformance Test Specification based on Action Requests received during the last few years. The most significant changes include the addition of a receive jitter test case and a device-coupler interoperability test.

  • Updates to the H1 Physical Layer Test Specification to remove obsolete profiles and align new references in the document with the current International Electrotechnical Commission (IEC) specifications. Coupler profiles were also added to the test specification.

  • Miscellaneous updates to the FOUNDATION fieldbus Cable Specification.

Implementation of the new FOUNDATION fieldbus H1 Physical Layer Test Specification Version 2.0 is not immediately required. However, fieldbus device developers are encouraged to start using the specification as soon as possible. The updated specification will become mandatory with the next major release of the Fieldbus Foundation”s Interoperability Test Kit ”ITK”. Until then, developers can still provide proof of conformance to Version 1.5 of the specification when registering a device.