PROFINET Applying the Ethernet Standard to
Peter Thomas Control Specialists Ltd www.controlspecialists.co.uk
Industrial Automation Automation Seminar Coventry – July 2014 PROFINET - Applying the Ethernet Standard - V1.0 - July 2014
Objectives 2
PROFINET - Applying the Ethernet Standard to Industrial Automation. • • • • •
A review of PROFIBUS PROFINET the natural evolution of PROFIBUS Connecting to existing Fieldbus systems Control System Configuration Network Monitoring Considerations
PROFINET - Applying the Ethernet Standard - V1.0 - July 2014
www.controlspecialists.co.uk
Review of PROFIBUS
• PROFIBUS is a multi-drop network where many devices are connected to one cable. • Every PROFIBUS device must have a unique address which is set by the engineer during set up • Up to 126 PROFIBUS devices can be connected together in a single network. • However only 32 devices can be connected on a segment. • Segments are formed using repeaters, hubs, optical links or couplers.
• DP devices run on RS485 cabling using shielded twisted pair cable terminated at the ends to stop reflections. • PA devices run on Manchester Bus Powered (MBP) cable. PROFINET - Applying the Ethernet Standard - V1.0 - July 2014
www.controlspecialists.co.uk
Review of PROFIBUS
• A PROFIBUS network must have a Class-1 master. The Class-1 master must be configured to communicate with its allocated slaves. • Each device has a GSD file which describes its characteristics, options, diagnostics etc.
• A Class-2 master can optionally be connected to the network for engineering functions such as parameter setting, calibration or diagnostics etc. • DP devices can run at a bit rate from 9.6kbit/s up to 12Mbit/s (all devices at the same bit rate). • PA devices always run at 31.25kbit/s.
PROFINET - Applying the Ethernet Standard - V1.0 - July 2014
Review of PROFIBUS • The protocol is a simple master slave communication with token passing between masters. • Only one device can talk at a time and communicational is one way at a time (half duplex). • Device start up is standardised and checks include: • ID number, unique identification for each type of device (check configured ID=device ID) • IO configuration (check modules present=modules configured)
• Standardised diagnostics. • Communication errors and peripheral errors.
• Standardised profiles • PA devices, drives, encoders, safety etc.
PROFINET - Applying the Ethernet Standard - V1.0 - July 2014
www.controlspecialists.co.uk
What is PROFINET? • PROFINET is an open Industrial Ethernet standard developed by the PROFIBUS Organisation. • It is NOT PROFIBUS over Ethernet. • PROFINET uses completely standard modern Ethernet (IEEE802.3). However, some features of PROFINET require additional standards to operate. • Ethernet is not a multi drop network. Each cable only connects two devices. Switches are used to branch from device to device with a maximum cable length between devices of 100m • Ethernet uses four core twisted pair screened cable • Termination (to stop reflections) is provided in every device and is no longer in the hands of the user.
PROFINET - Applying the Ethernet Standard - V1.0 - July 2014
www.controlspecialists.co.uk
PROFINET
• PROFINET is not a master/slave protocol. Full duplex communication is used which means that devices can read and write at the same time. • PROFINET operates at 100Mbit/s or faster. • PROFINET makes use of Existing IT standards but, unlike IT systems, is “real-time” and deterministic. • PROFINET is very well thought out to meet all the requirements of automation and control systems incorporating: • High speed time communication with a range of real-time performance classes. • Standardised communication and peripheral diagnostics. • Profiles for a wide range of applications.
PROFINET - Applying the Ethernet Standard - V1.0 - July 2014
www.controlspecialists.co.uk
PROFINET IO devices
IO-Controller
PROFINET Supervisor
E.g. PLC running application program.
E.g. PC or laptop running engineering tool application.
(Compare with PROFIBUS Class-1 master)
(Compare with PROFIBUS Class-2 master)
Ethernet
Configuration Control/monitoring Alarms
IO-Device
Diagnosis Status/Control Parameters
E.g. Field device with inputs/outputs (Compare with PROFIBUS Slave device) PROFINET - Applying the Ethernet Standard - V1.0 - July 2014
www.controlspecialists.co.uk
PROFIBUS and the OSI model
FMS
User layer application (7) OSI model
(3) to (6)
data link (2) physical (1)
PROFINET - Applying the Ethernet Standard - V1.0 - July 2014
FMS profiles Fieldbus Message Specification (FMS)
DP
PA
DP profiles
PA profiles
DP basic functions DPV0
DP extensions DPV1, DPV2
Not used
Fieldbus Data Link (FDL) RS485/Fibre optic
MBP interface
MBP(IEC61158-2)
www.controlspecialists.co.uk
PROFINET and the OSI model
Non time critical communications User layer Application Layer (7) Presentation Layer (6) Session Layer (5) Transport Layer (4) Network Layer (3)
Profiles
Real time communications Profiles
PROFINET Application Layer Not used
Not used
TCP/UDP
PROFINET Real-time channel
IP
Data Link Layer (2) Physical layer (1) PROFINET - Applying the Ethernet Standard - V1.0 - July 2014
Standard fast Ethernet. www.controlspecialists.co.uk
PROFINET IO
• Many features that have been developed for PROFIBUS devices have been directly incorporated into PROFINET: Standardised module and channel-related diagnostics, Alarm and status information, Identification and Maintenance (I&M) functions, Time stamping, Device description file (GSD) with configuration data for the device and available modules – PROFINET based on XML (called GSDML) • Highly deterministic process cycle timing.
• • • • •
PROFINET - Applying the Ethernet Standard - V1.0 - July 2014
www.controlspecialists.co.uk
Real-Time Operation
• What does “Real-Time” mean? • A real-time control system responds in a deterministic manner within a time which is short compared to the plant response time. • i.e. it depends on the application!
• Standard communications (IT) • requires a response in the order of ~100ms.
• Factory automation • requires a response time in the order of 1 to 10ms.
• Multi axis motion control • requires a response time in the order of 0.1 to 1ms with a jitter of less than 1µs.
PROFINET - Applying the Ethernet Standard - V1.0 - July 2014
www.controlspecialists.co.uk
Real-Time Operation • PROFINET makes use of: • TCP/IP for standard communications, achieving response times typically less than 100ms. • A Real-Time, RT, channel for I/O communications, achieving cycle times between 1 and 10ms. • Isochronous Real-Time, IRT, channel for highly deterministic performance (drives and servos), achieving cycle times down to 32µs with