Table of Contents
Advertisement
3. Fieldbus Integration With Experion System
3.2. Control Integration
to the fieldbus data structure (DS-66) of the CAS_IN_D parameter. It interprets the value
portion in Control Builder terms and converts it to fieldbus representation.
The CEE output agent also accepts a single BKCAL_OUT_D parameter with the
fieldbus data structure (DS-66) and maps it to the BACKCALIN parameter of the
DEVCTL block in Control Builder terms.
It sends the outgoing "control signal" either to a subscribed parameter or a client/server
written parameter through the CAS_IN_D or RCAS_OUT_D connection. It can
optionally receive the backcalculation signal from either the corresponding published
parameter or client/server read parameter.
The Control Builder data quality is converted to fieldbus data quality. The Control
Builder Good indication is represented as fieldbus Good (Cascade).
The Control Builder control initialization indicators map only to the limited number of
substatus conditions that have corresponding indications in fieldbus Good (Cascade).
Interface Connections Summary
Since the downstream action with the upstream feedback is the same for all fieldbus
blocks, there are essentially the following six types of interface connections through the
FIM.
Analog process value into the FIM.
a)
Discrete process value into the FIM.
b)
Analog process output from the FIM.
c)
Discrete process output from the FIM.
d)
Analog process output from the FIM with backcalculation feedback.
e)
Discrete process output from the FIM with backcalculation feedback.
f)
Note that types 5 and 6 support publish/subscribe communications in Cascade mode or
client/server communications in Remote Cascade mode. And, the analog values can also
be used in the Remote Out mode.
Fieldbus also supports direct device-to-device (peer-to-peer) publish/subscribe
connections independent of the FIM. The FIM can also monitor (subscribe to) the data
published between the functions blocks of these fieldbus devices.
A word about SCM parameter interaction
Sequential Control Module (SCM) Steps and Transitions can write to any contained
parameter of a fieldbus function block. The value of a contained parameter can be
54
Experion PKS Series A Fieldbus Interface Module User's Guide
Honeywell
R400
July 2010
Advertisement
Table of Contents
