Reference Manual
00809-0100-4021, Rev FB
August 2011
Rosemount 3144P
4-4
F
OUNDA
TION
Fieldbus
Block Execution times
F
OUNDATION
FIELDBUS
FUNCTION BLOCKS
For reference information on the Resource, Sensor Transducer, AI, LCD
Transducer blocks refer to “Function Blocks” on page A-9. Reference
information on the PID block can be found in the Function Block manual
Document No. 00809-0100-4783.
Resource Block (index number 1000)
The Resource Function Block (RB) contains diagnostic, hardware, and
electronics information. There are no linkable inputs or outputs to the
Resource Block.
Sensor Transducer Block (index number 1100)
The Sensor Transducer Function Block (STB) temperature measurement
data, includes sensor and terminal (body) temperature. The STB also
includes information about sensor type, engineering units, linearization,
reranging, damping, temperature compensation, and diagnostics.
LCD Transducer Block (index number 1200)
The LCD Transducer Block is used to configure the LCD display.
Analog Input Block (index number 1400, 1500, and 1600)
The Analog Input Function Block (AI) processes the measurements from the
sensor and makes them available to other function blocks. The output value
from the AI block is in engineering units and contains a status indicating the
quality of the measurement. The AI block is used for scaling functionality.
PID Block (index number 1700 and 1800)
The PID Function Block combines all of the necessary logic to perform
proportional/integral/derivative (PID) control. The block supports mode
control, signal scaling and limiting, feed forward control, override tracking,
alarm limit detection, and signal status propagation.
The block supports two forms of the PID equation: Standard and Series.
Choose the appropriate equation using the MATHFORM
parameter. The
Standard ISA PID equation is the default selection and Autotune.
Input Selector (index number 1900)
The signal selector block provides selection of up to four inputs and generates
an output based on the configured action. This block normally receives its
inputs from AI blocks. The block performs maximum, minimum, middle,
average, and ‘first good’ signal selection.
Block
Execution Time
Resource
–
Transducer
–
LCD Block
–
Advanced Diagnostics
–
Analog Input 1, 2, 3
60 ms
PID 1 and 2 with Autotune
90 ms
Input Selector
65 ms
Signal Characterizer
45 ms
Arithmetic
60 ms
Output Splitter
60 ms
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