Industry Conference and 22nd Annual Meeting General Purpose Single Pair Ethernet for Process Instruments David D. Brandt Rockwell Automation, Inc. Michael Bückel Endress+Hauser Flowtec AG Abstract ODVA has demonstrated industry leadership in Single Pair Ethernet (SPE) solutions. External promotion included liaison with IEEE P802.3cg project, and active stakeholder position in the APL Project. Domain-specific specification EtherNet/IP enhancements include an “In-cabinet” SPE solution (motor control components), and “Ethernet-APL” (process instruments for hazardous locations). Further specification enhancements are underway in the EtherNet/IP Physical Layer Special Interest Group for “GPSPE” (general purpose SPE). One intent of GPSPE is to utilize 10BASE-T1L to extend SPE use cases - by reaching out from inside the cabinet and into non-hazardous field locations. Another intent of GPSPE is to reference existing/emerging SPE standards rather than invent new technology. GPSPE will be useful to expand the application space of EtherNet/IP for constrained devices across industrial domains (discrete, hybrid, and process automation) – reducing the end- device electronics and field cabling. This paper discusses use cases and benefits when utilizing GPSPE with new Process Instruments. This paper also discusses minor changes that allow – EtherNet/IP end-devices using Ethernet-APL to interoperate with other GPSPE devices.
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ti . Industrial Ethernet is displacing fieldbus Including device networks and sensor networks l . Some displacement is difficult for multipair Ethernet Limited distance (100 m) and not intrinsically safe - Escalating cost, size, and power (i.e., migration to 1 Gb/s over - four-pairs) . Industrial SPE (IEEE Std 802.3cg-2019) emerged as a response! 10BASE-T1L for Ethernet-APL long distance (1000 m) and l intrinsic safety 10BASE-T1S to achieve a lowest cost solution -
Why continue the trend?
Fieldbuses
Multiple network types . . Technologies not familiar to graduates • Limited data flow (gateways) • Lack of security Industrial Ethernet with SPE • Single network type . Ethernet is familiar Free flow of information Security e
. ODVA leadership in SPE IEEE 802.3 liaison – Stakeholder in the APL Project l . Domain-specific EtherNet/IP specification using SPE: - Chapter 8-10 Industrial EtherNet/IP In- cabinet Bus Media and Physical Layer - Chapter 8-11 EtherNet/IP Media and Physical Layer for Ethernet-APL (Ethernet Advanced Physical Layer)
. EtherNet/IP Physical Layer Special Interest Group is developing an EtherNet/IP Specification Enhancements (ESEs) for General Purpose SPE (GPSPE) . Expand the application space of EtherNet/IP Discrete, hybrid, and process automation l Reduced edge-device electronics and field l cabling . “General purpose” references SPE standards rather than invent new technology IEEE (10BASE-T1L), ISO/IEC,  ANSI/TIA l . On-going effort - subject to change A GPSPE reaches from the cabinet and into non-hazardous field locations A Ethernet-APL reaches from the cabinet and into hazardous locations
EtherNet/IP for Constrained Devices GPSPE . Reduced Physical Layer – Cabling – Connectors Coupling circuit - EMC protection l – SPI MAC/PHY interface . Reduced protocol stack –   Less FLASH and RAM for smaller MCUs Transport (UDP-only) l Security (DTLS-only) l . A reduced Physical Layer . Can be used with a reduced protocol stack o . References IEEE Std 802.3-2022 Clause 104 (PoDL) . PSE and PD are Type E . Classes are 10-15 Added for long reach (1000 m) l and industrial usage l Classes 0-9 exist primarily for short reach (15 m) and automotive usage . Both Plug and Play and Engineered power are under consideration
Source: IEEE Std 802.3-2022 Table 104–2—Class power requirements matrix for PSE, PI, and PD for classes 10 through 15
Wet environments and typical industrial voltages More power over longer distance with smaller wires 7
. Non-hazardous process applications are prevalent . Process Skids l l l Specialty OEM modules Shipped to a site Interconnected via piping and supervisory communication to perform a series of production functions Distances are short l OEM applications are often cost-sensitive l . Life Sciences, Food and Beverage, and Water and Wastewater Plantwide automation (areas and lines), may l include skids Distances fall between skids and large plants l a
. The introduction of SPE (Ethernet-APL) is driving all instruments toward Ethernet connection in hazardous location . Harmonization on a full suite of EtherNet/IP instruments has these advantages: l Fast update l l l l . Reduction of gateways Reduction of cabling – single pair with power Increased information capability from instruments Multiple measurements from the same instrument Instruments in non-hazardous areas: Limited set of EtherNet/IP instruments + HART instruments - Traditional 2-wire instruments not available as EtherNet/IP l A GPSPE could drive all instrument types toward Ethernet connection in non-hazardous areas Example Instrument Types Flow Level Pressure Temperature Liquid Analysis
. Intrinsic safety fault protection adds cost . Cost factors: Redundant protection hardware - Agency certification - A GPSPE will have no intrinsic safety cost . Devices (especially switches) will be more cost effective . Intrinsic safety limits field device power . Ethernet-APL: 0.5 W (Ex ia) or 1 W (Ex ic) @ 15 Vdc . More power benefits some instruments Separate power cable is undesirable l Higher power budget is desirable - GPSPE will have no intrinsic safety power restriction . GPSPE is expected to specify PoDL (Power over Data Line) Classes 10,11 and 12 30 Vdc at up to 8.4 W -
. Vendors are preparing Ethernet-APL Field Devices for market . There is advantage in enabling these devices to attach to GPSPE Ethernet-APL hardware/firmware re-use l Faster GPSPE launch l . Ethernet-APL and GPSPE are both EtherNet/IP over 10BASE-T1L, but the power systems are different . GPSPE could include a compatibility mode that allows operation within both systems
PoDL PSE (Power Source Equipment) does not supply full voltage unless a PD (Powered Device) is present on the link Detection: l . . PSE sources a low voltage - PD draws a specified specific current if present PSE is pre-configured to supply a specific power Class SDO Classification: Serial protocol detections PD and negotiates power Class negotiation without pre- . configuration alignment may be possible . Ethernet-APL power source directly applies power PoDL circuitry is not intrinsically safety and reduces limited Ethernet-APL - power “PoDL-bypass” is simple method to power Ethernet-APL devices in GPSPE PSE is pre-configured to provide full voltage without Detection or l Classification. PSE utilizes PoDL coupling circuit and a subset of the state machines
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んEthernet-APL devices for GPSPE must operate from and tolerate at least 30 Vdc . GPSPE PoDL-bypass pre-configured voltage could be specified as 30 Vdc and/or 58 Vdc It is important to prevent damage - . GPSPE PoDL is expected to support both voltages and to retain the IEEE requirement for 10BASE-T1L is to tolerate up to 60 Vdc GPSPE devices would never be damaged by direct application of 58 Vdc - . Ethernet-APL Field Switches supply Class A and C power at 15 Vdc and Field Devices are not required to tolerate 60 Vdc Damage could occur even at 30 Vdc -
▷  It is proposed that GPSPE specify a PoDL-bypass option for Classes 10, 11 and 12 (30 Vdc) ▷  An Ethernet-APL device could be powered in a GPSPE system - if it operates from and tolerates 30 Vdc . Factors in voltage selection: − Limiting pre-configuration to 30 Vdc could preclude damage 8 W is considered adequate - Class 12 voltage drop across a 200 m cable is reasonable - •   9.5 Ω loop resistance / 400 m loop = 0.024 Ω/m (i.e.,18 AWG) 58 Vdc operation/tolerance increases component ratings, size, and heat dissipation l Additional qualification and installation restrictions may also apply when exceeding - 50 V due to potential shock hazard - especially true for wet installations
. Instruments should not be used outside their intended location (hazardous or non-hazardous) . The possibility of misapplication is reduced by: - Packaging and labelling without hazardous area approval markings - Avoiding reuse of the Ethernet-APL specified M8 and M12 connectors
. GPSPE continues the trend of using SPE to displace fieldbus, sensor, and device networks - and enabling networking of hardwired devices and point-point links . A complete portfolio of EtherNet/IP instruments is desirable Hazardous locations (Ethernet-APL) – Non-hazardous locations (GPSPE) l . GPSPE is anticipated to bring advantages to Process Instruments in non-hazardous locations: Reduced wiring – Lower cost by eliminating Intrinsic Safety l l Significant power . There is advantage in allowing Ethernet-APL instruments to be interoperable with GPSPE They must be designed appropriately – and social l of mome le mi _conのNO 0 s to o to on our of the form of the complete of the Industry Conference and 22nd Annual Meeting