The Input Selector Extended function block supports up to 8 inputs and selects the inputs either by direct selecting (OP_SELECT) or by applying a selected algorithm (SELECT_TYPE).
Direct selecting inputs
The parameter OP_SELECT is used to select a particular input by setting the value of OP_SELECT to the input number (1 through 8). For example, set OP_SELECT to 2 and IN_2 is direct selected. If OP_SELECT is zero, then the value of SELECT_TYPE is used.
Selection types
MAX Selects the highest valued input from those inputs that are not bad and are not disabled.
MIN Selects the lowest valued input from those inputs that are not bad and are not disabled.
MID Selects the mid valued input from those inputs that are not bad and are not disabled.
FIRST_GOOD Selects the first not disabled and not bad input, starting from IN_1.
AVG Averages those inputs that are not bad and are not disabled.
HOT_BACKUP Maintains the input selected from the previous scan, provided it is still usable. If it is not usable, HOT_BACKUP advances to the next usable input, counting up from the selected input number from the previous scan.
Block errors
The following 16 conditions can be reported in the BLOCK_ERR parameter:
Other
Block Configuration error: the selected channel carries a measurement that is incompatible with the engineering units selected in XD_SCALE, the L_TYPE parameter is not configured, or CHANNEL = zero.
Link Configuration error
Simulate Active: Simulation is enabled and the block is using a simulated value in its execution.
Local Override
Device Fault State Set
Device Needs Maintenance Soon
Input Failure/Process Variable has Bad Status: The hardware is bad, or a bad status is being simulated.
Output Failure: The output is bad based primarily upon a bad input.
Memory Failure
Lost Static Data
Lost NV Data
Readback Failed
Device Needs Maintenance Now
Power Up
Out of Service: The actual mode is Out of Service.