Rockwell Automation Publication 1756-RM006K-EN-P - November 2018 397
Output Parameter Data Type Description
EnableOut BOOL Indicates if instruction is enabled. Cleared to false
if Out overflows
Out REAL The calculated output of the algorithm.
Average REAL The calculated average of the algorithm.
Status DINT Status of the function block.
InstructFault (Status.0) 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.
InFaulted (Status.1) BOOL In health is bad. InFault is set.
NumberOfSampInv (Status.2) BOOL NumberOfSamples invalid or not compatible with
array size.
Structured Text
Operand Type Format Description
block tag MOVING_STD_DEV structure MSTD structure
StorageArray REAL array Holds the In samples. This
array must be at least as large
as NumberOfSamples.
See Structured Text Syntax for more information on the syntax of expressions
within structured text.
Description
The MSTD instruction supports any input queue length. Each scan, if
SampleEnable is set, the instruction enters the value of In into a storage array.
When the storage array is full, each new value of In causes the oldest entry to be
deleted.
The MSTD instructions uses these equations for the outputs:
Condition Action
Average
Out
The instruction will not place an invalid In value (NAN or INF) into the
storage array. When In is invalid, the instruction sets Out = In, sets Average = In,
and logs an overflow minor fault, if this reporting is enabled. When In becomes
To Next Page
Loading...
Need help?
General
