Criteria for Design and Specification
NeSSI Issues
Presentation to IFPAC Regarding NeSSI Generation 2 Bus
January, 29, 2008
Bob Farmer
IFPAC-NeSSI Report.ppt; 29 January 2008; Slide 1 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 2 Siemens Energy & Automation, Inc.
Basic Bus Configuration and System Concept
Controlling Unit
(SAM) B B B B
V
P T
A
IFPAC-NeSSI Report.ppt; 29 January 2008; Slide 3 Siemens Energy & Automation, Inc.
Extended System Concept
?
Controlling Unit
(SAM) B B B B
V
P T
A
AC Power ?
DC Power
IFPAC-NeSSI Report.ppt; 29 January 2008; Slide 4 Siemens Energy & Automation, Inc.
Extended System Concept
Ambient Environment
Cabinet
System Environment
B
Controlling Unit
(SAM) B B B B
B
V
P T
A
AC Power
DC Power
IFPAC-NeSSI Report.ppt; 29 January 2008; Slide 5 Siemens Energy & Automation, Inc.
Component Electrical Implementation
Bus electronics;
Bus including drivers and Intrinsic Safety barriers; and
power source Standardized interface to
component electronics
Bus
Definition
Proprietary component-specific
SAM – including electronics by component
vendor
Bus source and Point of
software Bus
Interface
Proprietary mechanical NeSSI
component by component
vendors
Point of Assembly and certification of the
Substrate complete component
Interface
Substrate
Definition
NeSSI Substrates
IFPAC-NeSSI Report.ppt; 29 January 2008; Slide 6 Siemens Energy & Automation, Inc.
Design Criteria
System
Bus and Cable
Components
IFPAC-NeSSI Report.ppt; 29 January 2008; Slide 7 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 8 Siemens Energy & Automation, Inc.
Bus Design Criteria Power Requirements:
Sensors: 10-40ma
Controllers: 20-70ma
Valve pilots: 80-350ma
Capacity Number of components on bus:
– Number of devices Typical: 5-15
– Types of devices Common: 20-30
Maxum: 200
– 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 Design goal for flammability ignition
– Device representation temperature to be T4 (135°C) with minimum
– Device function at least T3 (200°C).
– Maintenance issues
Component ambient temperature to be
– Configuration / addressing / identity
>=70°C
Capability for the standard functions to be
implemented in a variety of ways.
IFPAC-NeSSI Report.ppt; 29 January 2008; Slide 9 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 10 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 11 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
IFPAC-NeSSI Report.ppt; 29 January 2008; Slide 12 Siemens Energy & Automation, Inc.
Questions - Discussion
IFPAC-NeSSI Report.ppt; 29 January 2008; Slide 13 Siemens Energy & Automation, Inc.