Allen-Bradley LOGIX 5000 Reference Manual page 338

Chapter 3 Filter
338
Output Parameter
EnableOut
Out
DeltaT
Status
InstructFault (Status.0)
WNotchInv (Status.1)
QFactorInv (Status.2)
OrderInv (Status.3)
TimingModeInv (Status.27)
RTSMissed (Status.28)
RTSTimeInv (Status.29)
RTSTimeStampInv (Status.30)
DeltaTInv (Status.31)
Structured Text
Operand Type
NTCH tag FILTER_NOTCH
See Structured Text Syntax for more information on the syntax of expressions
within structured text.
Description
The NTCH instruction uses the Order parameter to control the sharpness of the
cutoff. The QFactor parameter controls the width and the depth ratio of the
notch. The NTCH instruction is designed to execute in a task where the scan rate
remains constant.
The NTCH instruction uses this equation:
where i is the Order operator with these parameters limits (where DeltaT is in
seconds):
Rockwell Automation Publication 1756-RM006K-EN-P - November 2018
Data Type Description
BOOL Indicates if instruction is enabled. Cleared to false if Out
overflows.
REAL The calculated output of the algorithm.
REAL Elapsed time between updates. This is the elapsed time in
seconds used by the control algorithm to calculate the process
output.
DINT Status of the function block.
BOOL The instruction detected one of the following execution errors.
This is not a minor or major controller error. Check the
remaining status bits to determine what occurred.
BOOL WNotch < minimum or WNotch > maximum
BOOL QFactor < minimum or QFactor > maximum
BOOL Invalid Order value.
BOOL Invalid TimingMode value.
For more information about timing modes, see Function Block
Attributes.
BOOL Only used in real time sampling mode. Set to true when
ABS (DeltaT - RTSTime) > 1 millisecond.
BOOL Invalid RTSTime value.
BOOL Invalid RTSTimeStamp value.
BOOL Invalid DeltaT value.
Format Description
structure NTCH structure