powerpoint-plc vs dcs emerson
DESCRIPTION
PLC vs DCSTRANSCRIPT
SI-MRT-XX-105 [2]
A Technical ComparisonA Technical Comparison
DCS versus PLC’sPresented
By
Jim Cushman
Emerson Process Management
Power & Water Solutions
[File Name or Event]Emerson Confidential27-Jun-01, Slide 2
SI-MRT-XX-105 [2]
Relays
Electrical
Instrumentation
Loop
Controllers
Integrated
Control
Process Controls
DCS
Field Intelligence,
Comm Tech,
IT Integration
PlantWeb
Evolution in AutomationEvolution in AutomationEvolution in Automation
1970 1980 1990 2000
Low cost
Compact
Factory Automation
µP Control
PLCs
PID loops
Logic sequences
[File Name or Event]Emerson Confidential27-Jun-01, Slide 3
SI-MRT-XX-105 [2]
History of PLCHistory of PLCHistory of PLC
� Developed from Automotive Assembly and Factory Automation where discrete points are used
� Developed to replace mechanical timers and solid state relays
� Evolved where process restart is not a major concern but processing speed is important
� Designed with digital logic as the most important design feature
[File Name or Event]Emerson Confidential27-Jun-01, Slide 4
SI-MRT-XX-105 [2]
History of DCSHistory of DCSHistory of DCS
� Evolved from single loop controllers
� Evolved from analog based signal handling
� Evolved with extensive involvement from the process control end-users
� Developed with alarm handling, diagnostics and fail safe as important design feature
[File Name or Event]Emerson Confidential27-Jun-01, Slide 5
SI-MRT-XX-105 [2]
DCS Designed with Latest TechnologyDCS Designed with Latest DCS Designed with Latest TechnologyTechnology
� Windows or Solaris platform
� “Off-the-shelf” Pentium controller
� “Off-the-shelf” Ethernet network
� Oracle configuration database
� Oracle historical process data
� AutoCAD control builder
(varies between vendor)
DCS Architecture
PLC-MMI Architecture
Realtime
Data
Server
(Single point
failure here)
CTLRCTLR CTLRCTLR
[File Name or Event]Emerson Confidential27-Jun-01, Slide 7
SI-MRT-XX-105 [2]
Remote Site
Redundant
RadiosPLC/RTU
RS232 or Ethernet
Repeater Site
In Out
Radio Repeater
eDBOvation
Engineer
Redundant
SCADA Servers
Ovation Network
RS232 or Ethernet
Control Room
DCS - SCADA ConfigurationDCS DCS -- SCADA ConfigurationSCADA Configuration
CTLRCTLR
Local Site
[File Name or Event]Emerson Confidential27-Jun-01, Slide 8
SI-MRT-XX-105 [2]
Comparison Of PLC & DCSOperator InterfaceComparison Of PLC & DCSComparison Of PLC & DCSOperator InterfaceOperator Interface
� PLC HMI have a separate database from the control system and needs to be configured separately. Database consistency is a major issue
� Alarms and faceplates have to be specially configured
� PLC station to station communications are tedious and are via third party integrators
� Requires the use of network servers, external hard disks with huge configuration effort
� Limited OPC server functionality
� DCS HMI is part of the single integrated database
� DCS has built in feature in the HMI as standard and optimized for handling alarm messages and data from controllers
� Real time integration is available via a serial card, OPC, or NetDDE.
� Transaction integration is via Historian.
[File Name or Event]Emerson Confidential27-Jun-01, Slide 9
SI-MRT-XX-105 [2]
Comparison of PLC & DCSConfiguration Vs ProgrammingComparison of PLC & DCSComparison of PLC & DCSConfiguration Vs ProgrammingConfiguration Vs Programming
� PLC Programming is usuallythe familiar ladder logic
� PLC Programming requires writing of logic for alarms and signal conditioning
� Challenge to write analog PID control using ladder logic
� DCS configuration uses graphical function blocks that follow SAMAstandards
� DCS configuration comes with alarms and signal conditioning as standard, part of the database parameters
� It is generally easier to understand a Boolean Logic Block diagram than separate analog logic diagram and ladder logic diagram
[File Name or Event]Emerson Confidential27-Jun-01, Slide 10
SI-MRT-XX-105 [2]
DCS Windows EditionDeveloper StudioDCS Windows EditionDCS Windows EditionDeveloper StudioDeveloper Studio
� System Configuration
� Tools
� System Database Tools
� Control Builder
� Graphics Builder
[File Name or Event]Emerson Confidential27-Jun-01, Slide 12
SI-MRT-XX-105 [2]
Comparison of PLC & DCSControl AlgorithmsComparison of PLC & DCSComparison of PLC & DCSControl AlgorithmsControl Algorithms
� PLC does not have standard algorithms and requires programmers to build the logical conditions and equations from scratch
� Besides having a standard library of algorithms such as PID, lead-lag, etc., DCS also features other in DCS such as drag-and-drop configuration and graphical
configuration.
[File Name or Event]Emerson Confidential27-Jun-01, Slide 13
SI-MRT-XX-105 [2]
� The DCS System Database manages all items in the system
– Input, output and calculated points
– Control modules
– Process graphics
– System configuration
� This allows simplified engineering via standard drag & drop functionality
– Drag & drop points, control, graphics and system configuration to desired locations
– Download changes
DCS Developer StudioDCS Developer StudioDCS Developer Studio
[File Name or Event]Emerson Confidential27-Jun-01, Slide 14
SI-MRT-XX-105 [2]
Data and Event Historian of PLC & DCS Operator InterfaceData and Event Historian of PLC & Data and Event Historian of PLC & DCS Operator InterfaceDCS Operator Interface
� Data historian is often a basic package supplied by the HMI software vendor
� Little analysis and exportingcapability
� Difficult to integrate a sophisticated historianpackage and requires a new configuration database
� DCS uses a sophisticated historianengine as a standard.
� The link and configuration is integrated within the single database of DCS. Analysis of cause and effect can be done.
[File Name or Event]Emerson Confidential27-Jun-01, Slide 15
SI-MRT-XX-105 [2]
DCS Operator Interface - HMIDCS Operator Interface DCS Operator Interface -- HMIHMI
[File Name or Event]Emerson Confidential27-Jun-01, Slide 16
SI-MRT-XX-105 [2]
DCS DCS eDBeDB Historian Architecture Features Historian Architecture Features Distributed Data ScannersDistributed Data Scanners
OPC Server
WEStation
DCS WDPFII
Third-Party
TCP/IP
Network
eDBHistorian
eDBHistorian
Controller
� Data scanning is de-coupled from the eDB database server
� Scanners to be available for DCS, WDPF and OPC
� Scans process values and sends exceptions, aggregates and messages to the eDB
� Scanner buffer stores during brief network or server outages
� Does not rely on process data network — requires only TCP/IP
[File Name or Event]Emerson Confidential27-Jun-01, Slide 17
SI-MRT-XX-105 [2]
Alarm Management of PLC & DCSOperator Machine InterfaceAlarm Management of PLC & DCSAlarm Management of PLC & DCSOperator Machine InterfaceOperator Machine Interface
� Certain alarms and faceplates have to be specially configured
� Very basic alarm handling capability that is built for discrete industry
� Difficult to bring maintenance bits/flags into alarm system.
� Difficult to relate alarms with
operational philosophy
� DCS alarm management is built upon the strength of DCS
� DCS enhances alarm management by
– minimizing nuisance alarms
– simplifying alarm tracing
[File Name or Event]Emerson Confidential27-Jun-01, Slide 18
SI-MRT-XX-105 [2]
DCS Operator Station FunctionsDCS Operator Station FunctionsDCS Operator Station Functions
Process Diagrams
Point Menu
Trends
Alarm System
Point Reviews
Options
� Compatible with Solaris
process diagrams
� Triggers display of trends,
graphics and point information
� 3-D graph option
� Drag & Drop trend building
with points
� Trend groups
� Alarm List, Alarm History,
Unacknowledged Alarms &
Reset List functions
� DCS alarm functionality - 4
high & 4 low limits
� Iconic and audible alarms
� Similar to Solaris but with
different look & feel
� DCS membrane keyboard
and dual-CRT options
[File Name or Event]Emerson Confidential27-Jun-01, Slide 19
SI-MRT-XX-105 [2]
DCS Operator Station FunctionsDCS Operator Station Functions
� Tabs for mode switching between List, History,Unacknowledged, and Reset displays
� Find function to locate alarm points
� Title bars move for more or less information displayed
� Moveable menu tool bar
� Number of alarm windows configurable based on system limitations
� Line-by-line printing of alarm messages to a local printer
� User-selectable fonts; standard alarm fields displayed or removed by menu selection
� Audible alarms use Wave files
Alarm System
[File Name or Event]Emerson Confidential27-Jun-01, Slide 21
SI-MRT-XX-105 [2]
Comparison of PLC & DCSSmart Transmitter InterfaceComparison of PLC & DCSComparison of PLC & DCSSmart Transmitter InterfaceSmart Transmitter Interface
� PLC presently lack smart interfaces and have to use workaround solution
� Not proactive Field Bus and Open Architecture technologies
� HART is available with DCS
� DCS provides implementation to Foundation Fieldbus in a customer plant
[File Name or Event]Emerson Confidential27-Jun-01, Slide 22
SI-MRT-XX-105 [2]
Manage
the
Process
DCS
Manage
the Field
Devices
AMS Inside
HART AI & AO
Modules
AMS Pass
Through SW
Control RoomMaintenance Shop
DCS with HART I/O Modules & AMSDCS with HART I/O Modules & AMSDCS with HART I/O Modules & AMS
CTLR CTLR
[File Name or Event]Emerson Confidential27-Jun-01, Slide 23
SI-MRT-XX-105 [2]
AMS (Asset Management Software)AMS (Asset Management Software)AMS (Asset Management Software)
[File Name or Event]Emerson Confidential27-Jun-01, Slide 24
SI-MRT-XX-105 [2]
Comparison of PLC & DCSDiagnostics and Failure HandlingComparison of PLC & DCSComparison of PLC & DCSDiagnostics and Failure HandlingDiagnostics and Failure Handling
� PLCs have relatively little diagnostic status and may only be indicative
� Limited use of diagnostic bits in logic
� All key diagnostic bits reflecting system health status can participate in logics for proper safety actions
� DCS diagnostics allow us to drill down all the way to the fieldinstruments including HART & Fieldbus.
� DCS I/O is selectable either in HOLD-LAST or FAIL-SAFE positions in the event of failure
[File Name or Event]Emerson Confidential27-Jun-01, Slide 25
SI-MRT-XX-105 [2]
Comparison of PLC & DCSAdvanced ControlComparison of PLC & DCSComparison of PLC & DCSAdvanced ControlAdvanced Control
� PLC has limited advanced control features
� A primitive auto-tuningsoftware is all they can show
� DCS has all the depth and experience of implementing advanced control
� DCS has a full suite of advanced control applications to improve yield and productivity known as “ Smart Process”
[File Name or Event]Emerson Confidential27-Jun-01, Slide 26
SI-MRT-XX-105 [2]
Comparison of PLC & DCSHardware FunctionalityComparison of PLC & DCSComparison of PLC & DCSHardware FunctionalityHardware Functionality
� PLC I/O does NOT support hot swap especially those in remote areas
� Limited redundancy options
� DCS cards have complete diagnostic and hot swapcapability
� DCS has redundancyoptions for most key hardware components
� A highly scalable system that allows you to add/change or upgradeworkstation, controller, I/O online.
[File Name or Event]Emerson Confidential27-Jun-01, Slide 27
SI-MRT-XX-105 [2]
Lower Total Cost of OwnershipLower Total Cost of OwnershipLower Total Cost of Ownership
� Total cost of ownership, including long term maintenance, upgrades, and replacement cost, is typically lower for a DCS.
– configuration savings
– start up savings
– long term maintenance
– upgrade/expansion
– change management vs. replacement
[File Name or Event]Emerson Confidential27-Jun-01, Slide 28
SI-MRT-XX-105 [2]
You DecideYou DecideYou Decide
� A PLC-HMI system will work. It will run your plant. It will do ladder logic. It will even do PID control.
– Can you integrate well with external systems?
– Do you have easy to use Advanced Control?
– Do you have performance monitoring software?
– Do you have an integrated asset management solution?
� DCS provide best value, highest return, lowest long term running cost.
AMS
Systems ComparisonSystems ComparisonSystems Comparison
Redundancy
Ovation
Siemens PCS7
Rockwell ProcessLogix
Rockwell ControlLogix
Controller Redundancy Yes Some Some Some
Controller Power Supply Redundancy
Yes Some Some Some
Communications Redundancy
Yes Some Some No
Programming/Configuration
Drag & Drop Configuration Yes Some Some Some
Device Configuration Change Tracking
Yes No No No
Configuration Audit Trail Yes No No No
Systems Comparison (Cont’d.)Systems Comparison (ContSystems Comparison (Cont’’d.)d.)
Traditional Control Technology
Ovation Siemens PCS7
Rockwell ProcessLogix
Rockwell ControlLogix
Regulatory Yes Some Yes Some
Sequence Yes Yes Some Yes
Advanced Control Technology
Fuzzy Logic Yes No No No
Neural Network Technology Yes No No No
Auto-Tune Technology Yes No Some Some
Multivariable Predictive Control Yes No No No
Systems Comparison (Cont’d.)Systems Comparison (ContSystems Comparison (Cont’’d.)d.)
Service and Support
Ovation Siemens PCS7
Rockwell ProcessLogix
Rockwell ControlLogix
24 x 7 Technical Support - Worldwide
Yes Some Some Some
Configuration Services Yes Yes Some Some
Hardware Maintenance Services
Yes Some Some Some
Installation Services Yes Yes Some Some
Software Support & Upgrade Support
Yes Some Some Some
Training Yes Yes Some Some
Single Source Supplier Yes Some Some Some
Systems Comparison (Cont’d.)Systems Comparison (ContSystems Comparison (Cont’’d.)d.)
System Management
Ovation Siemens PCS7
Rockwell ProcessLogix
Rockwell ControlLogix
Event Historian Yes Some Some Some
Sequence of Events Recording
Yes Some Some Some
Asset Management Yes No No No
Global Database Yes No No No
Alarm Time Stamping Yes No Some Some
System Architecture
DCS / PLC Integration Yes Some Some Some
Scalable Yes Some Some Some
OPC Support Yes Some Yes Yes
Automated System Time Management
Yes Some Some Some
Automated System Diagnostics
Yes Some Some Some
Systems Comparison (Cont’d.)Systems Comparison (ContSystems Comparison (Cont’’d.)d.)
System Aspects
Ovation
Siemens PCS7
Rockwell ProcessLogix
Rockwell ControlLogix
Time Synchronization Capability
Yes No No No
Online Upgrade Yes No No No
Modifications without Shutdown
Yes No No No
Support for Control in the Field
Yes No No No
OPC Alarms and Events Yes No No No
Scalability Yes Some Some Some
I/O Simulation Capability Yes No No No