Ethernet in Hazardous Areas

Ethernet can now fulfill hazardous area safety requirements. From today’s perspective it does not yet seem viable to equip field devices with an Ethernet connection. However, Remote I/O systems can build a bridge between traditional field instrumentation and the Ethernet.

The illustration below shows the structure of a system in hazardous areas where the operator can have access locally or from a central position. The Ethernet connection is designed with an increased safety level of protection while the field signals are connected using intrinsic safety.

In addition to increased safety, optical intrinsic safety "op is" in accordance with IEC60079-28 is also used. While copper leads are suitable for close ranges up to 100 m, fiber optic connections cover distances up to 2 km or more. Ethernet Remote I/O uses existing, tried and tested I/O modules that link all functionalities required for process instrumentation to the Industrial Ethernet.

Ethernet Remote I/O permits a combination of analog and digital signals to be used in the same slave. It supports NAMUR or switching signals and solenoid valve outputs as well as temperature inputs or the supply of 2 or 4-wire transmitters, proportional valves and positioners.

As with previous Remote I/O systems, maintenance without a hot work permit is possible. The bus communication is neither impaired nor jeopardized by the replacement of modules.