Emerson DXP-FF, Installation, Operation & Maintenance Manual

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D-Series with FF Option
Installation, Operation & Maintenance
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Input
Function
Block
Calculation
Or Control
Function
Block
Output
Function
Block
Input
Function
Block
Calculation
Or Control
Function
Block
Output
Function
Block
Channels
Resource
Block
Transducer
Block
Process
Sensors
Process
Actuators
Function
Block
Function
Block
Channels
Resource
Block
Transducer
Block
Process
Sensors
Process
Actuators
Function
Block
Function
Block
Appendix A: F
OUNDATION
Fieldbus Technology
Blocks and the User Application
The Fieldbus Foundation has defined a standard for building user applications. The Foundation standard is built
around “Blocks.” Blocks are used to represent different types of functions that the device performs and provide a way
of grouping different parameters and functionality together in an easy to understand framework.
A Fieldbus Foundation device has a Resource Block, Transducer Block, and Function Blocks.
Once the hardware of the TopWorx Sensor-Communication Module (hereafter known as SCM-FF) is set up, fieldbus
communication is used to set the transducer parameters to get the functionality desired. The desired transducer func-
tionality is associated with a function block. The host system is then used to link the function blocks together, and the
application is downloaded to all of the devices in the loop.
Resource Block
The Resource Block describes characteristics of the fieldbus device such as the device name, manufacturer, and se-
rial number. There is only one resource block per device.
Transducer Blocks
Transducer Blocks are the connection of Function Blocks to the real world. Many of the settings unique to a Fieldbus
Device are defined in the transducer block parameters.
The Function Blocks are typically standard between devices, so that they may be linked together to form easily con-
structed, interoperable applications. The Channels of a transducer block can be attached to a function block for use in
the application.
Function Blocks
Function Blocks provide the control system behavior. The input and output parameters of Function Blocks can be
linked over the fieldbus. The execution of each Function Block is precisely scheduled. There can be many function
blocks in a single user application.
The SCM-FF provides 5 Discrete Input (DI) and 3 Discrete Output (DO) function blocks. Configuration of all these
blocks is NOT required for full device operation.
Process Instrument and its Blocks
An application is built by linking together function blocks.