IM 01C25R03-01E
A-22
APPENDIX 3. INPUT SELECTOR (IS) BLOCK
Output Parameters (Computation or Selection Results)
OUT: Block output
SELECTED: Indicates the input number selected using the alternatives.
Other Parameters
OUT_RANGE
: Sets the OUT range.
STATUS_OPTS
: Option used to specify the handling of various statuses.
SELECT_TYPE
: Determines the input selection algorithm.
MIN_GOOD
: Parameter specifying the minimum required number of inputs with “good” status. If the number
of inputs that are “good” is less than the value of MIN_GOOD, input selection is canceled.
Mode
O/S
: Allows configuration change, but disables input value output.
Man
: Allows internal processing, but the output value may vary depending on the definition of usage conditions.
Auto : Outputs the input value.
The Input Selector (IS) block offers a maximum of eight input alternatives and generates the output according to the
configured action. This block generally receives inputs from the Analog Input (AI) function block. The function of
the IS block is to select a maximum, minimum, middle, average, “first good,” or “latched good” signal. The block
combines parameter configuration (DISABLE_n) and option (“first good”) to give priority to alternative(s) or to
function as a rotary position switch. When used as a rotary position switch, the block can receive operator inputs or
switch information from connected inputs.
The IS block supports the concept of middle selection. This function outputs the average of two middle signals if
even multiple valid signals are configured or a middle signal if odd multiple valid signals are configured. Application
of the block is to supply a selected control signal in the forward path.
The SELECTED parameter is the 2nd output indicating which input has been selected using the algorithm.
