Measuring and controlling data at a distance

By Morand Fachot

Data acquisition and monitoring are important elements of industrial processes and plant management since they help improve operational efficiency. The sensors, cameras and other hardware that are used to accomplish these tasks communicate with each other through standardized protocols, which increasingly enable wireless transmission.

Wireless operation. Wireless operation.

Small effects – big consequences

Unexpected equipment failures can cost time and money and add risk to otherwise safe operations if left undetected. For example, a plugged filter can cause damage to a critical pump. Wireless monitoring will detect differences in pressure, but also vibrations that may indicate pump failure to allow preventive action. This helps avoid accidents and repair costs and contributes to more reliable operations.

Protecting investment – satisfying compliance

Modern plant and field management relies extensively on automated monitoring, measurements and controlling to protect assets, oversee processes, protect workers, increase productivity and generally detect safety, health and environmental compliance.

From fixed installations to wireless

Often, the hard-wiring of physical devices such as temperature, vibration and pressure sensors, cameras, radio hardware, RFID (radio-frequency identification) and more, is technically challenging and costly. A wireless bridge solution may be more appropriate. One of the most important standards in wireless process automation relies on the HART (Highway Addressable Remote Transducer) protocol that was developed by HCF (HART Communication Foundation) with the participation of major players from the process automation and industrial wireless industries. The aim was to enable the wireless interoperability of intelligent measurement and control devices from different vendors. The protocol was brought into the international consensus process and published as IEC 62591, Industrial communication networks - Wireless communication network and communication profiles - WirelessHART™.

Interoperability and safety built-in

The International Standard provides the protocol for high-level security, encryption, verification, authentication and key management. Devices from different manufacturers are able to communicate safely with each other through gateways and the existing plant communications network. Since IEC 62591 consists of an extension to the wired HART protocol, the millions of installed wired devices easily integrate with it and are able to communicate with the new generation of wireless devices. The built-in mesh design allows devices to be easily added, moved or removed. Interestingly, wireless devices that are built based on the protocol may also be able to unlock data that is stored in wired devices, which previously were not able to communicate their information.

Customized messaging – low power consumption

The protocol specified in IEC 62591 supports multiple messaging modes, including one-way publishing of process and control values, spontaneous notification by exception, ad-hoc request/response and block transfer of large data sets. It also supports on-demand communication, which is important for remote or difficult-to-access devices that rely on battery power to operate. Most other LAN or bus protocols require continuous communications that drain batteries quickly. Finally, redundant routes based on latency, efficiency and reliability ensure that messages reach their destination without data loss.

Stimulating innovation and technology roll-out

With the IEC 62591 protocol it has become possible to automate measurements that were previously out of physical or economic reach. And, as is the case whenever an industry standard becomes an International Standard, it encourages multiple manufacturers to develop new products and solutions, stimulating innovation and technology roll-out.

Wireless operation. Wireless operation.
Industrial automation. Industrial automation.
Robot assisted automation. Robot assisted automation.