Solving the Issue of Interoperability among Devices and Systems

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Solving the Issue of Interoperability among
Devices and Systems

• ISA100 Wireless Solutions Summit
• 19 May 2008

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Presenter

• David D. BrandtPrincipal EngineerRockwell
  AutomationAdvanced Technology
  Milwaukeeddbrandt_at_ra.rockwell.com

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About the ISA100 Standard Activity

• Multiple protocol support on a single, integrated
  wireless network (ISA100.11a)
  
• ISA100.11a native
• HART
• FOUNDATION Fieldbus
• PROFIBUS
• Modbus
• CIP
• Others
• Multiple radio support in a family of standards
  (ISA100)
  
• Process Automation (Process Focus)
• Factory Automation (Discrete Focus)
• Transmission and Distribution (Long Distance
  Focus)
  
• RTLS/RFID (Industrial Tagging Focus)

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Challenge How to provideInteroperability among
Devices and Systems?
HART, FOUNDATION Fieldbus, PROFIBUS, Modbus,
CIP, ...
HART, FOUNDATIONFieldbus, PROFIBUS, Modbus,

CIP, ...
ISA100.11a,WirelessHARTTM,ZigBee,
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A specific challengeISA100.11a / WirelessHART
Interoperability

• ISA100-WirelessHART Joint Analysis Team (JAT)
  addressed this issue
  
• The ISA100.11a draft standard has followed the
  recommendations for release 1
  
• Enable dual-mode gateways
• Develop a common high-side interface in the
  gateway
  
• As a common model and interface for mixed systems
  and devices
  
• Base the interface on the WirelessHART optional
  XML interface
  
• Specify as an implementation neutral Service
  Access Point
  
• Provide enhanced tunneling for application layer
  protocols
  
• Provide generic wireless network management that
  is separate from the application protocols
  
• Provide information to facilitate coordination of
  RF usage
  
• Convergence below the gateway will be considered
  for later releases

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Multimode Gateway withCommon High-side Interface
Other applications
Protocol translator and stack to communicate with
plant network of choice
Common High-side Interface
Otherspecific interfaces
ISA100.11a Stack (PHY through APP)
WirelessHART Stack (PHY through APP)
Other Stack
WirelessHARTspecific interfaces
ISA100.11a specific interfaces
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Gateway ServiceAccess Point (GSAP)

• Session
• Lease
• Messaging
• Publish/subscribe
• Client/server
• Source/sink
• Bulk transfer
• Alert
• Reports
• Device List
• Topology, Schedule
• Device Health, Neighbor Health, Network Health
• Time Synchronization
• Gateway configuration

This is the Common High-side Interface used by
protocol translators.
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GSAP Session Service
Protocol translators act on behalf of plant
applications to establish sessions with the
gateway entity through the GSAP session service.
Sessions allow resource allocation for a specifi
c network. Resources are reclaimed when a sessi
on ends.
Session
Translatingproxy
ProtocolTranslator
Gateway
GSAP
Gateway Entity
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GSAP Lease Service
Protocol translators act on behalf of plant
applications to establish leases within sessions
to allocate specific communication resources.
Leases allow dynamic resource allocation and rel
ease. Resources are allocated within the gatewa
y entity, the network, or both.
Specific types of leases are available for publ
ish/subscribe, client/server, bulk transfer and
alerts
Lease
Translatingproxy
Protocol
Translator
GSAP
Gateway Entity
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GSAP Messaging Services
Translatingproxy
Message Services
BulkTransferClient
Protocol translators act on behalf of plant
applications to utilize lease-based messages
services to perform messaging that supports
protocol translation. Protocol specific applica
tion content is carried in the messages.
Publish
Subscribe
Client
Server
Alert
Buffer
Buffer

• Large item transfer
• Reliable, in-orderdelivery

Buffer
Buffer
Buffer
Buffer

• Change of state delivery
• Local caching
• Synchronization

• Optional caching

Buffer
Buffer
Alert
Subscribe
Publish
Server
Client
BulkTransferServer
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GSAP Report Services
CommonReports
Translatingproxy

Protocol
Translator
Common reports available, independent of the
underlying wireless technology.
Gateway

GSAP

Gateway
Entity
Report Generation
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GSAP Device List Report Service
Protocol translators present each wireless device
as if it were a wired device within the plant
network. The device list report service allows
the wireless devices to be discovered and mapped
into the plant network, ultimately linking to the
control strategy. Each device has a globally un
ique identifier. EDDL and other device descript
ion methods extensions can enable linkage without
additional tools.
PlantNetwork
Proxy1
Proxy2
Proxy3
Proxy4

Protocol
Translator
GSAP
Gateway Entity
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GSAP Health Report Services
Health reports are available to alert control
systems to underlying problems in a generic
manner. Health reports are also available to as
set management systems for maintenance purposes.
Protocol translators are responsible for convers
ion to specific formats.
Translating proxy

Protocol
Translator
DeviceHealth
NeighborHealth
NetworkHealth
Gateway

GSAP

Gateway
Entity
Report Generation
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GSAP Topology Report Service,Schedule Report
Service
Topology and Schedule reports enable the ability
to drill down when a Health report indicates a
communication problem. When devices from differ
ent types of wireless networks share the same
physical space, channel and transmission schedule
can be evaluated for coexistence improvement
opportunities.
Translating proxy

Protocol
Translator
Topology
Schedule
Health

GSAP

Gateway
Entity
Report Generation
Errors
Errors
Time,Channel
Network 1Node 1
Network 1Node 2
Time,Channel
Network 2Node 1
Network 1Node 2
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GSAP Time SynchronizationService
Services are available to synchronize underlying
wireless networks to an external source.
This is useful when the same source is used in a
control system. This is also useful to synchro
nize wireless device communication across
wireless networks. Protocol translators can ada
pt a variety of sources.
Translatingproxy

Protocol
Translator
Gateway

GSAP

Gateway
Entity
Time Synchronization
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Example wireless deviceintegration scheme
FOUNDATIONFieldbusApplication
HARTApplication
MultipleSystems
PROFIBUSApplication
A single wireless device (single catalog number)
can operate across multiple systems.
A specific protocol translator is required in th
e gateway for each system. ISA100.11a provides
an efficient application model that native
devices can use for this purpose.
Translatingproxy
Translatingproxy
Translatingproxy
MultipleProtocolTranslators
Gateway
GSAP
Gateway Entity
SingleGenericDevice
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Example wired deviceintegration scheme
FOUNDATIONFieldbusApplication
HARTApplication
MultipleSystems
PROFIBUSApplication
Wired devices can operate across multiple
systems. A simple protocol translator is requir
ed in the gateway to tunnel each protocol.
Adapters must also implement the tunnel protocol
. ISA100.11a provides an efficient tunneling mo
del that can be used for this purpose.
Translatingproxy
Translatingproxy
Translatingproxy
TunnelingProtocolTranslators
Gateway
GSAP
Gateway Entity
SingleDevice
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Conserving battery lifeMinimizing transactions
with caching
Caching reduces transactions (increasing battery
life). Caching gives immediate response to appl
ication if used properly. Both ISA100.11a nativ
e messaging and tunneled messaging utilize cache
techniques.
PlantNetwork
Informationis routed throughgateway cache
Gateway
Buffer
Buffer
Native Information
TunneledInformation
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Conserving battery lifeReducing header sizes
PlantNetwork
ApplicationContent
PlantNetwork WiredPacket
Address
Length
Data
IntegrityCheck
Gateway
MAP
CARRY
CREATE
CREATE
WirelessPacket
Address
Length
Data
IntegrityCheck
MAP
CARRY
CREATE
CREATE
TunneledDeviceWiredPacket
Address
Length
Data
IntegrityCheck
Enhanced tunneling reduces the size of packets
(increasing battery life) via a configuration
agreement to map and create fields rather than
carrying them. ISA100.11a native messaging prov
ides numerous mechanisms to reduce header size.
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Benefits to Users

• Protects investment in legacy devices and
  protocols
  
• Reduces the lifecycle cost associated with
  gateways
  
• Acquisition cost (less gateways)
• Training and Maintenance cost (common gateway
  model)
  
• Provides a future migration path
• For wired devices
• For improved wireless technology
• First step on path to more complete integration
  with WirelessHART, anticipated to be upgradeable
  to Release 2 approach without impacting higher
  level applications

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Benefits to Vendors

• Reduces development cost and time
• Design to a common gateway model
• Independent of plant network
• Independent of low-power wireless network
• Single paradigm fits both ISA100 and
  WirelessHART architectures
  
• Enables value-added integration enhancements
• E.g., time synchronization across networks
• E.g., coexistance coordination tools