Allen-Bradley LOGIX 5000 Reference Manual page 333

Filter
The LPF instruction uses these equations:
When: The instruction uses this Laplace transfer function:
Order = 1
Order = 2
Order = 3
with these parameters limits (where DeltaT is in seconds):
Parameter
WLag first order
LowLimit
WLag second order
LowLimit
WLag third order
LowLimit
HighLimit
Whenever the value computed for the output is invalid, NAN, or
instruction sets Out = the invalid value. When the value computed for the output
becomes valid, the instruction initializes the internal parameters and sets Out =
In.
Affects Math Status Flags
Controllers
ControlLogix 5580
CompactLogix 5370, ControlLogix
5570
Major/Minor Faults
None specific to this instruction. See Common Attributes for operand-related
faults.
Rockwell Automation Publication 1756-RM006K-EN-P - November 2018
Limitations
Affects Math Status Flags
No
Yes for the output
Chapter 3
INF, the
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