Emerson Rosemount 5400 Series - Page 297

285
Reference Manual
00809-0100-4026, Rev HA
Appendix I: Analog-Input block
November 2014
Analog-Input Block
Appendix I Analog-Input Block
Simulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . page 288
Damping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . page 289
Signal conversion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . page 289
Block errors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . page 290
Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . page 290
Alarm detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . page 291
Configure the AI block . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . page 293
Figure I-1. Analog-Input Block
The Analog-Input (AI) function block processes field device measurements 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 measuring device may have
several measurements or derived values available in different channels. Use the channel number
to define the variable that the AI block processes.
The AI block supports alarming, signal scaling, signal filtering, signal status calculation, mode
control, and simulation. In Automatic mode, the block’s output parameter (OUT) reflects the
process variable (PV) value and status. In Manual mode, OUT may be set manually. The Manual
mode is reflected on the output status. A discrete output (OUT_D) is provided to indicate
whether a selected alarm condition is active. Alarm detection is based on the OUT value and
user specified alarm limits. Figure 2 on page 288 illustrates the internal components of the AI
function block, and Table 1 lists the AI block parameters and their units of measure,
descriptions, and index numbers.
Table I-1. Definitions of Analog-Input Function Block System Parameters
Parameter
Index
number
Units Description
ST_REV 01 None
The revision level of the static data associated with the function block.
The revision value will be incremented each time a static parameter
value in the block is changed.
TAG_DESC 02 None The user description of the intended application of the block.
STRATEGY 03 None
The strategy field can be used to identify grouping of blocks. This data is
not checked or processed by the block.
OUT=The block output value and status
OUT_D=Discrete output that signals a selected
alarm condition
OUT_D
AI
OUT