Emerson Rosemount 848T, Reference Manual, Page: 123 / 136

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Reference Manual
00809-0100-4697, Rev GA
Appendix D: Function Blocks
November 2014
Function Blocks
D.3 Input selector function block
The Input Selector (ISEL) function block can be used to select the first good, Hot Backup
™
,
maximum, minimum, or average of as many as eight input values and place it at the output. The
block supports signal status propagation. There is process alarm detection in the Input Selector
function block.
Table D-6 lists the ISEL block parameters and their descriptions, units of
measure, and index numbers. The block execution time is 30 ms.
IN (1-8) = Input
DISABLE (1-8) = Discrete input used to disable the associated input channel
SELECTED = The selected channel number
OUT = The block output and status
OUT_D = Discrete output that signals a selected alarm condition
Table D-6. Input Selector Function Block Parameters
Number Parameter Units Description
1 ST_REV None The revision level of the static data associated with the
input selector block. The revision value will be
incremented each time a static parameter value in the
block is changed.
2 TAG_DESC None The user description of the intended application of the
block.
3 STRATEGY None The strategy field can be used to identify groupings of
blocks. This data is not checked or processed by the
block.
4 ALERT_KEY None The identification number of the plant unit. This
information may be used in the host for sorting alarms,
etc.
5 MODE_BLK None The actual, target, permitted, and normal modes of the
block.
Actual: The mode the “block is currently in”
Target: The mode to “go to”
Permitted: Allowed modes that target may take on
Normal: Most common mode for target
SELECTED
OUT
OUT_D
ISEL
IN_1
IN_2
IN_3
IN_4
IN_5
IN_6
IN_7
IN_8
DISABLE_1
DISABLE_2
DISABLE_3
DISABLE_4
DISABLE_5
DISABLE_6
DISABLE_7
DISABLE_8
OP_SELECT