Topologies

Ethernet-APL can be applied to any industrial Ethernet protocol such as EtherNet/IP, HART-IP, OPC UA and PROFINET. This makes integration much easier for planners, plant manufacturers, and plant operators since gateways or other protocol interfaces are no longer needed for the Ethernet-based infrastructure, which considerably minimizes the time and cost for planning and engineering. Additionally, Ethernet-APL utilizes existing infrastructure concepts: connectors and cable types so that they can be re-used. This protects the investments in installation and instrumentation.

The new Ethernet advanced physical layer is designed to support any relevant installation topology. The following two examples are typical for process plants—a compact plant layout and a long-reach plant layout.

The DIN-rail switch provides functionality and connections for the star topology. Each instrument connects to a spur line. The backbone can be configured as a redundant ring. Users choose this topology to meet the following features and requirements:

• Indoor installations as seen in chemical or pharmaceutical industries or in food and beverage installations
• Switches installed in junction boxes or control panels
• Cable lengths of up to 200 m to the instrument
• Ethernet redundancy often required at the plant level or inside the control cabinet
• Explosion protection for any hazardous area

Ethernet-APL for long-reach plants utilizes the trunk-and-spur topology. This topology can serve outdoor installations as seen in the oil and gas or wastewater industries. Ethernet-APL connects to the top level inside the control cabinet via the Ethernet-APL power switch. It supports ring redundancy for high availability. The Ethernet-APL field switch provides the intrinsically safe barrier for the spur outputs and receives power from the trunk. This is similar to today’s FieldConnex® solutions with Power Hubs, FieldBarriers, and Segment Protectors.

Users select the trunk-and-spur topology to serve the following features and requirements:

• Cable lengths of 1000 m to the field
• Field switches powered via the two-wire cable
• Distribution to multiple instruments via junction box in the field
• Ethernet redundancy at the plant level
• Explosion protection for any hazardous area

This layout is 100 % compatible with the trunk-and-spur topology popular in fieldbus installations. It provides a path for migration projects because the installed cable can be reused.

Ethernet-APL supports the trunk-and-spur topology, which is a defacto standard in process industries that uses digital communication and fieldbus. Existing two-wire installations can thus be reused. This not only saves costs and protects investments, it also significantly reduces installation time. The multidrop communication common with fieldbus is separated into point-to-point communication via switches, which means that possible faults can only affect this individual connection. The availability of the system thus improves over the long term because cross talk is eliminated. Plug and play connectivity also ensures that new devices can be integrated quickly and easily into existing fieldbus infrastructure.

Instrumentation with PROFIBUS PA communications can stay in place as the switches from Pepperl+Fuchs adapt to the communication and protocol and automatically translates the device data into PROFINET. This function is based on standardized PROXY-Profile technology, thus enabling this feature with any DCS system or controller that support this profile.