HART-IP: simplifying data exchange

25 September 2016

Control Engineering Europe reports on HART-IP which is helping ensure that 4-20mA devices continue to have something to offer in an increasingly digital world.

The release of HART-IP in 2012 was timely, when considering the findings of an IMS Research study from February 2013, which predicted that use of Industrial Ethernet in the process industry would almost double from 2011 to 2016.

Today, the HART protocol can be run over Ethernet, Wi-Fi, or other network media without sacrificing the detailed device setup or diagnostics information of existing networks. HART-IP allows simplified vertical data integration from the field device through to the control room. In addition to providing access to the process variables of a device, the protocol also supports device parameterisation and advanced diagnostics. “Together, WirelessHART and HART-IP will play an important role in enabling the Internet of Things in process plants in the future,” said Thomas Hilz, market segment manager at Softing Industrial Automation.

The HART-IP solution

With the growing importance of WirelessHART and increasing digitisation at the field level in process plants, it is expected that more users and system providers will move their focus to HART-IP. The HART-IP application layer is based on the same application layer commands as 4-20 mA/HART and WirelessHART. It provides plant-wide solutions and enables interoperability between devices and applications.

HART-IP works over standard Ethernet (IEEE 802.3) – both copper and fibre – as well as Wi-Fi (IEEE 802.11) equipment so it is suitable for use with standard infrastructure components such as LAN switches, routers, access points, cables and connectors. In addition, it can utilise existing network structures with redundant Ethernet media as well as mesh or ring topologies, or Power over Ethernet (PoE). Various speeds like 10 Mbit/sec, 100 Mbit/sec and 1 Gbit/sec are supported.

IP-based communication enables multiple protocols to share the same network, each protocol with a specific application. So, HART-IP can coexist with IT protocols and other industrial Ethernet-based protocols and there is no need for dedicated infrastructure. The use of multiple clients and servers is also supported, enabling multiple controllers and software applications to access the data in one or more gateways or multiplexers over the same network.

Two certainties

Moore Industries International believes that, in an uncertain world there are two certainties in industry today – a continued increase in use of Ethernet and the continued installation of HART devices which means that the next natural step is for users to start utilising HART over Ethernet.

With over 60 million HART field devices already installed in manufacturing facilities across the globe, there is a huge amount of untapped process and diagnostic data in the field. “While traditional twisted pair HART transactions with masters and field devices can be somewhat slow, HART over Ethernet, or HART-IP alters the future landscape of HART availability at the local intranet or intra-plant level and also across corporate WANs and ERP systems,” said a Moore Industries spokesperson.

With HART process variables and diagnostic data encapsulated in HART-IP packets, it is possible for critical and real-time plant floor process parameters to be transmitted across the globe in the blink of an eye utilising existing corporate network backbones that employ corporate VPNs (Virtual Private Networks) or other secure TCP/IP networks.

“Many plants still have silos of process information in different formats that have to be translated or converted and consolidated to a central process database or server,” said the spokesperson. “From there the data can be pushed or pulled to other areas of the facility or company. This translation costs money and takes time for initial configuration and maintenance. The same often happens with HART data from the plant floor.” Either a gateway or a HART host application, such as an asset manager, then has to convert the HART data into a more usable data format that can be readily interpreted and utilised by higher level systems such as Enterprise Resource Planning (ERP) systems. These communication gateways, OPC servers, software drivers and data translation tools all cost money on the front end and require maintenance.

Moore Industries is a supplier of rail, panel and field instruments for industrial process control and monitoring, system integration and factory automation. It is now fitting all of its future HART gateways and remote I/O systems with HART-IP capability. “We see this as the next big step in HART communications that will remove a layer of transmission delay and cost for the end user,” continued the spokesperson. “In addition to increased speed and reduced cost, HART-IP allows a standard and seamless communication link to and from the HART field device from anywhere within the corporate network, assuming you have security access. Being able to query, diagnose or re-range a device from any PC workstation corporate-wide over standard Ethernet networks allows immediate operating expense reductions.

“Additionally, the use of HART-IP packets allows existing routers, layer-three switches and network security appliances to further deploy security tools and tactics using standard IP methods such as IP address ghosting, filtering and subnet parsing. We believe that HART-IP will eventually become one of the leading plant floor communication protocols, especially as more vendors like us adopt and implement HART-IP in their devices and equipment.

“Today, HART-IP is commonly used in combination with WirelessHART and a HART multiplexer to allow parameters, diagnostic data and process values from a HART field device to be easily transferred to any location in the world – wired, wireless, via the internet, without loss of data accuracy and with the required level of security, says Kurt Polzer of Siemens “Applications using HART-IP could include remote monitoring, local or world-wide predictive or preventive maintenance. It can make applications and plants more transparent, reduces cost and increases availability and performance,” he concluded.

Conclusion

Interest in HART-IP continues to grow and more vendors are now providing devices and systems that support it. While it might not revolutionise the entire process industry, it certainly looks set to provide a significant contribution to simplifying the exchange of data and information in process plants which is vital as the industry sets out in on its Industry 4.0 journey.