Page 64  Foundation Fieldbus RMA803 Remote Indicator User's Guide  Revision 4 
5.7  Input Selector block 
The Input Selector block performs maximum, minimum, middle, average and ‘first good’ input 
selection. The Input Selector block provides selection of up to eight inputs and generates an output 
based on the selected type of input. The block functions as a rotary position switch, or a validated 
priority selection based on the use of the first good parameter and the disable_n parameter. As a 
switch, the block receives switching information from either the connected inputs or from an 
operator input. The block supports signal status propagation. 
The block is used to provide control input selection in the forward path only, and hence no back 
calculation support is provided. SELECTED indicates which input has been selected or the number 
of inputs selected by the algorithm. The block does not support process alarms. 
 
 
Figure 12: Input Selector block 
Execution 
Input processing 
If DISABLE_n is True, the corresponding input IN_n is discarded. If there are no inputs left, or if 
there are inputs fewer than MIN_GOOD inputs, then the value of SELECTED becomes zero.