Networks strategy for control systems 28 Septembre 2001 Networks strategy for control systems Patrice Noury

No any single solution meets all the needs System issues ALSTOM address several market segments having specific needs: Performances for control functions, dynamic time response, synchronisation Credibility for supporting control functions across the network Safety related functions to ensure process safety Remote and advanced diagnostics to support scheduled maintenance Quality and flexibility of engineering via tools Long lasting of system components, upgrade control Transparent access for on-demand reporting No any single solution meets all the needs

Ethernet summary Availability of general purpose equipment: Commodity item for office automation Large support from IT world Used in conjunction with TCP/IP High speed and very high speed available Limited availability of advanced features and ruggedised environment Priority traffic class expediting features Multicast over switch for selected branches Industrial environment IEC/ISO standard not reflecting latest IEEE publications, implementations are conforming to minimum standard address lower layers only (physical & data link)

Ethernet a commonly available LAN Ethernet summary (2) Application layer not stabilised, many initiatives are on-going: HSE Fieldbus Foundation-ALSTOM is member of the consortium IDA ODVA IONA ProfiNet Many others such as IEC 61850 (substation) Real time protocols exists but private based on TDMA type techniques Cabling is still point to point with two links (star) Cannot be considered as trusted for safety related systems- subject for future work in IEC 61508 Ethernet a commonly available LAN

WorldFIP summary Genuine real time fieldbus developed for multiple qualities of service Standardised in CENELEC/IEC Scheduled exchanges with multiple simultaneous cycles to fit process demand Industrial messaging TCP/IP support Highly robust to harsch environment with continued service Bus type topology, suitable for cost effective cabling system Trusted component suitable for safety related system up to SIL3 (according to IEC 61508)

WorldFIP use all the available bandwidth: WorldFIP summary (2) Limited availability, but components can be fully developed based on the standard. Due to its inherent flexibility, traffic should be organised, tools are available. WorldFIP use all the available bandwidth: Traffic is scheduled on a per variable basis, no need for any time allowance Variable addresses are not related to device address, no need for extra time slot, or agreed time slot Global efficiency above 80 % Industrial reliability of implementation, lifetime over 15 y WorldFIP a high quality trusted fieldbus

Systems are a collection of functions: Class of functions Systems are a collection of functions: Control, high speed data acquisition, synchronisation Monitoring, supervision Event logging, data historian Configuration offline or online incl. on demand processing Maintenance online Safety related function Video Each system instance has its own mix leading to a communication architecture hierarchy

Function requirements Real time type scope integrity Security Pro vable Control, data acquisition Schedule X cycles Short known Local field Yes med No yes Data flow confined Supervision On changes Long Local plant N/Y rmte Open access Events logs Event driven time tagged traceabilty Configuration, programming On request seg Y/N Download Servlet Maintenance On request during operation seg, uknwn World wide Y Transparent access, applets Safety control Local funct YES high Resilient tolerant Audio/Video monitoring uknwn N

Control architecture requires a defined hierarchy and scoping: Approach Compromise is necessary as only one communication architecture will be implemented Other exchanges have to use the remaining bandwidth of the chosen networks Control architecture requires a defined hierarchy and scoping: Sampling rates are determined by the physics and synchronised Real time requirements are coming loose for upper levels of process optimisation Real time communication should also support on demand communication

Generic architecture Inter-partners Plant management Ethernet ATM, SDH... Plant management Ethernet coordination Gateway Router IP addressing Real time Real time Real time WorldFIP Available protocols hart, CS103, Modbus

Architecture features Transparent access from top to bottom IP address for each device allow a direct access to target equipment without proxies Web technology for browsing device capabilities and health Scheduled traffic MPS, multi-period sampling Control exchanges are done according to process requirements No over-sampling Redundancy, availability Support of device and network redundancy confidence assessment can be done without additional feature for high integrity functions (IEC 61508) Testability and validation Ability to demonstrate conformance to spec.

Train Control Architecture

Train control architecture Features mfg cost savings flexibility for commissioning and development reliability and maintainability improvement weight saving integration of safety related functions (SIL 3) Functions breaking, traction control information display and monitoring passenger comfort and information (incl. Audio)

Power plant control architecture Intranet Controcad Centralog Simulation Centralog Optiplant + Controtest Controbloc Acquisition 1ms cycle Fieldbus subscribers Cycle base 50ms P320 Ethernet WorldFIP

Power plant control architecture Distributed intelligence for easier engineering Flexible redundancy management of evolution (non regression) High integrity level environment cyclic processing of control with no interrupt known load no influence of messaging over cyclic processing integration of safety functions certified by Bureau Veritas for flame burner management (as regards IEC 61508…)

conclusions No single solution for conflicting requirements, but Ethernet has wider acceptance for LAN Importance of IP rather than Ethernet for transparent access and integration in IT system, What application layer over TCP/IP? Unrivalled added value of WorldFIP for data sampling, control function and time sync., Growing importance of system integrity and need for trusted communication, justifying WorldFIP choice. To benefit of both thanks to com architecture