IFPAC-NeSSI Report.ppt; 29 January 2008; Slide 1 Siemens Energy & Automation, Inc.
Criteria for Design and Specification
NeSSI IssuesPresentation to IFPAC Regarding NeSSI Generation 2 Bus
January, 29, 2008Bob Farmer
IFPAC-NeSSI Report.ppt; 29 January 2008; Slide 2 Siemens Energy & Automation, Inc.
Topics
Overview; terminology
Design criteria– System issues
– Bus and cabling
– Components
Product and marketing issues
IFPAC-NeSSI Report.ppt; 29 January 2008; Slide 3 Siemens Energy & Automation, Inc.
Basic Bus Configuration and System Concept
VTP
A
Controlling Unit (SAM) B B B B
IFPAC-NeSSI Report.ppt; 29 January 2008; Slide 4 Siemens Energy & Automation, Inc.
Extended System Concept
VTP
A
Controlling Unit (SAM) B B B B
DC Power
AC Power
?
?
IFPAC-NeSSI Report.ppt; 29 January 2008; Slide 5 Siemens Energy & Automation, Inc.
Extended System Concept
VTP
A
Controlling Unit (SAM) B B B B
DC Power
AC Power
B
B
Cabinet
System Environment
Ambient Environment
IFPAC-NeSSI Report.ppt; 29 January 2008; Slide 6 Siemens Energy & Automation, Inc.
SAM – including Bus source and
software
Component Electrical Implementation
NeSSI Substrates
Proprietary mechanical NeSSI component by component
vendors
Bus including drivers and power source
Proprietary component-specific electronics by component
vendor
Bus electronics;Intrinsic Safety barriers; and
Standardized interface to component electronics
Assembly and certification of the complete component
Bus Definition
Point of Bus
Interface
Substrate Definition
Point of Substrate Interface
IFPAC-NeSSI Report.ppt; 29 January 2008; Slide 7 Siemens Energy & Automation, Inc.
Design Criteria
System
Bus and Cable
Components
IFPAC-NeSSI Report.ppt; 29 January 2008; Slide 8 Siemens Energy & Automation, Inc.
System Design Criteria
Overall system configuration and size– Minimum– Typical– Maximum
Ambient environment– Impact on bus external to system enclosure
System environment– Impact on bus internal to system enclosure– Impact on components and devices in system
Component capabilities and requirements– Power issues– Native capabilities and implementation methods regarding safety concerns– Market volume: available development resource commitment and impact on bus interface
development
IFPAC-NeSSI Report.ppt; 29 January 2008; Slide 9 Siemens Energy & Automation, Inc.
Bus Design Criteria
Capacity– Number of devices– Types of devices– Participating suppliers
Physical Issues / Installation– IP ratings / protection– Ambient conditions– Certifications / safety– Chemical resistance
Electrical– Length– Installed base / compatibility– Load capacity / load management– Power distribution– Interruption / interchange– Reliability / EMI / RFI– Instances / continuity
Software– Device representation– Device function– Maintenance issues– Configuration / addressing / identity
Component ambient temperature to be >=70°C
Design goal for flammability ignition temperature to be T4 (135°C) with minimum at least T3 (200°C).
Capability for the standard functions to be implemented in a variety of ways.
Number of components on bus:Typical: 5-15Common: 20-30Maxum: 200
Power Requirements:Sensors: 10-40maControllers: 20-70maValve pilots: 80-350ma
IFPAC-NeSSI Report.ppt; 29 January 2008; Slide 10 Siemens Energy & Automation, Inc.
Cabling Issues
Cable size, bend radius, height
Connection methods and system design
Jacket materials
Cost
IFPAC-NeSSI Report.ppt; 29 January 2008; Slide 11 Siemens Energy & Automation, Inc.
Component Design Criteria
Primary component performance
Physical size and shape
Mounting constraints
Power consumption
Diagnostic support
Ambient and physical ratings (see also Bus and Cabling)
Chemical and atmospheric tolerance (see also Bus and Cabling)
IFPAC-NeSSI Report.ppt; 29 January 2008; Slide 12 Siemens Energy & Automation, Inc.
Other Product Marketability Issues
System responsibility– Supplier: Integrator, component manufacturer, bus provider– System elements: Bus master, components, cables and peripherals– Field support– Training– Configuration and implementation difficulties– Issues with interchangeability
Spare parts and long term support– Field diagnosis and repair plan– Component support life: longevity in a “capital” investment versus short life span
of electronic and software techniques
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