Migration from Classical
EtherCAT simplifies Control Architecture Example: Hydraulic Press Control Architecture, Schuler AG, Germany
Classical Fieldbus Control Architecture Classical Fieldbus Performance leads to Decentralized Control Architecture Decentralized black box controllers for electric and hydraulic motion control Separate Network for functional Safety PC + PLC + NC
Issues with classical Control Architecture Different Programming Tools and Languages for PLC, PC, NC, Hydraulic Controller + Safety Complex and costly training of maintenance personnel Hardware Diversity High Costs for Spares Inventory Different Interfaces and Bus Systems for different Devices High Costs for Implementation, Maintenance and Diagnosis of these interfaces No influence on black box hydraulic control Limited Process optimization possibilities No differentiation from competitors (other press makers) Therefore Request to migrate to simplified and uniform control architecture
Migration to EtherCAT, Step 1 Less Hardware + Software Controlled Motion for better Process Results PLC, NC now PC Software Electric and hydraulic motion control moved to PC based control
Migration to EtherCAT, Step 2 Uniform Control Architecture, simplified interfaces, reduced costs Safety over EtherCAT integrated Just one bus system remaining: EtherCAT
Configuration: Classical Fieldbus Systems 1. Select + Plan Topology according to System Limitations 2. Configure Node Address at Slave Device 3. Select and Configure Baudrate, depending on: - Network Length + Topology - EMI-Environment - Application Requirements 4. Select Device Description Files (GSD, EDS) in Configuration Tool 5. Select and Configure Communication Parameters, such as: - cyclic Polling - event driven Communication - synchronized or free running 6. Allocate physical to logical Process Image (Mapping) 7. Optimize ( tune ) the Communication Parameters for best Network Performance
Configuration: EtherCAT 1. Select + Plan Topology according to System Limitations 2. Configure Node Address at Slave Device 3. Select and Configure Baudrate, depending on: - Network Length + Topology - EMI-Environment - Application Requirements 4. Select Device Description Files (GSD, EDS) in Configuration Tool 5. Select and Configure Communication Parameters, such as: - cyclic Polling - event driven Communication - synchronized or free running 6. Allocate physical to logical Process Image (Mapping) 7. Optimize ( tune ) the Communication Parameters for best Network Performance
Error Localization: Classical Fieldbus Systems CAN based systems: every node checks every frame for bit errors and flags the frame accordingly (Error Frame) Profibus: Destination node checks frame for bit errors Both CAN and Profibus provide good error detection mechanisms, but no error localization features M Furthermore, EMI disturbances travel along the bus line Thus: very difficult to find the source of bus errors EtherCAT Technology Group, 2009 12
Error Localization: EtherCAT EtherCAT: every node checks every frame for bit errors and flags the frame accordingly (Frame Check Sequence) Due to the physical ring, errors are located So EtherCAT combines good error detection mechanisms with excellent error localization features M Furthermore, EMI disturbances are gone after the next node, since the signal itself is generated from scratch Thus: very simple to find the source of bus errors EtherCAT Technology Group, 2009 13
Costs: EtherCAT vs Classical Fieldbus Systems EtherCAT is the only Industrial Ethernet System that claims to match or undercut Fieldbus Cost levels TCO (Total Cost of Ownership): Device Costs Infrastructure Costs Engineering Costs Setup Costs Maintenance Costs License Costs
Migration from classical Fieldbus to EtherCAT PLC NC Fieldbus Master Fieldbus Master Fieldbus I/O Fieldbus I/O Changing the entire architecture at once is sometimes considered too risky. Sometimes fieldbuses are used to integrate special purpose or custom controllers and sensors, that contain special know-how of the machine builder or system integrator the investment into these devices has to be protected Fieldbus I/O Special Purpose Controller Special
Migration from classical Fieldbus to EtherCAT PLC NC EtherCAT I/O EtherCAT I/O EtherCAT I/O Fieldbus Master EtherCAT is fast enough to replace classical backplane bus systems, too Thus EtherCAT / Fieldbus gateways do not form a performance bottleneck They help to protect the investment and provide a smooth migration path Fieldbus Master Special Purpose Controller Special
Migration from classical Fieldbus to EtherCAT PLC NC EtherCAT I/O EtherCAT I/O EtherCAT I/O In the next step more and more devices are moved to the EtherCAT network Fieldbus Master Special Purpose Controller Special
Migration from classical Fieldbus to EtherCAT PLC NC EtherCAT I/O EtherCAT I/O EtherCAT I/O Finally, the fieldbus master is not required any more Special Purpose Controller Special
Migration from classical Fieldbus to EtherCAT Gateways do not only provide a smooth migration path, they have other advantages as well: No Slots in Control System (IPC or PLC) required any more Nevertheless maximum expandability EtherCAT
Summary EtherCAT allows for simplified control architectures Setup and configuration is also simplified EtherCAT meets or even undercuts fieldbus cost levels Migration from classical fieldbus system is smooth.