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10. Appendix A
10.1. Fieldbus Technology
Communication layer description
The following table provides a summarized description of the communication layers that
make up the F
OUNDATION
library of detailed reference specifications including a Technical Overview and Wiring
and Installation Guides.
REFERENCE - INTERNAL
Please refer to
Fieldbus network references for a list of available documents or visit the
Fieldbus Foundation web site
and ordering data.
Layer
Physical
Data Link (DLL)
378
Experion PKS Series A Fieldbus Interface Module User's Guide
Fieldbus. The Fieldbus Foundation maintains a complete
Functional Description
Defines the transmission medium for fieldbus
signals and the message conversion tasks
to/from the Communication Stack.
Based on the Manchester Biphase-L Encoding
technique, so a F
OUNDATION
device interprets a positive transition in the
middle of a bit time as logical "0" and a
negative transition as logical "1".
Complies with existing International
Electrotechnical Commission (IEC 1158-2) and
the Instrumentation, Systems, and Automation
Society (ISA S50.02) physical layer standards.
And, it can be used with existing 4 to 20mA
wiring.
Defines how messages are transmitted on a
multi-drop network. It uses a deterministic
centralized bus scheduler called a Link Active
Scheduler (LAS) to manage access to the
fieldbus. It controls scheduled and unscheduled
communications on the fieldbus in a
publish/subscribe environment.
Identifies device types as Basic Device, Link
Master, or Bridge. A Link Master device type
can become a Link Active Scheduler (LAS) for
the network.
Honeywell
http://www.fieldbus.org/
Fieldbus (FF)
for additional details
Associated Terms
H1, 31.25 kbit/s
signal rate
H1 Link
H1 Segment
HSE, High Speed
Ethernet
Compel Data (CD)
message
Pass Token (PT)
message
Time Distribution
(TD) message
Live List
Link Active Scheduler
(LAS)
R400
July 2010
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