to pop up its description (if any).
An instance of this Basic Function Block type, whose operation is
defined by the Execution Control Chart (ECC) shown above and the
Ladder Diagram (LD) algorithm below, provides the logic for
simulating the loading and unloading of a pallet lifter, for
instance in the LIFTER_MVL
system configuration.
Additionally, an instance of this type determines whether a fault
has occurred in the pallet lifter. A non-fatal fault is indicated by
an event at the WARN output, and a fatal fault by an
event at the FLT output. An event at the CLR
output indicates that no fault is present. Specific fault conditions
are identified by the Boolean outputs of the block.
The top-to-bottom execution order of the REQ algorithm
is used to compute the CRUSHED
and FALLEN
conditions by using the previously existing values of the HALF_IN
and HALF_OUT conditions, respectively, before computing
their new values.
