Instruction Manual

Instruction Manual
D103434X012
Blocks
November 2014
127
Figure B‐14. Input Selector Function Block Schematic
fieldbus−fbus_229a
IN_1
IN_2
IN_3
IN_4
DISABLE_1
DISABLE_2
DISABLE_3
DISABLE_4
OP_SELECT
Selection
Algorithm
AUTO
MAN
OUT
SELECTED
MIN_GOOD
SEL_TYPE
SELECT_TYPE
NOTE: THIS FIGURE DOES NOT INCLUDE THE ADDITIONAL
4 INPUTS IN THE EXTENDED PARAMETERS.
Status Handling
Quality Use and Propagation
In Auto mode, OUT [7] reflects the value and status of the selected input based on the following criteria:
D A bad or disabled input is never used by any of the selection algorithms
D For a selection algorithm to use an input with status of Uncertain, the STATUS_OPTS [10] parameter must have
“Use Uncertain as Good.”
D STATUS_OPTS [10] is applied before selection.
D If the number of good inputs is less than MIN_GOOD [20], or if the number of inputs evaluated is 0, the status of
OUT [7] and SELECTED [21] will be Bad.
D If an input is disabled or its status is Bad and is selected via OP_SELECT [22], then the status of OUT [7] and
SELECTED [21] will be Bad. If the quality of the input is Uncertain, and the selection for the STATUS_OPTS [10]
parameter is “Use Uncertain as Good,” then the status of OUT [7] and SELECTED [21] will be Uncertain. Otherwise
the status of OUT [7] and SELECTED [21] will be Good Noncascade.
When the block is in the Manual mode the status and substatus of OUT [7] and SELECTED [21] will be as follows:
D Substatus will be non‐specific and the limit will be constant.
D Quality of OUT [7] and SELECTED [21] will be Uncertain if STATUS_OPTS [10] is “Uncertain if in Manual mode.”
Otherwise, the quality of OUT [7] and SELECTED [21] will be Good Noncascade.