Minimum Capture (MINC)

Minimum Capture (MINC)

This information applies to the CompactLogix 5370, ControlLogix 5570, CompactGuardLogix 5370, GuardLogix 5570, CompactGuardLogix 5380, CompactLogix 5380, CompactLogix 5480, ControlLogix 5580, and GuardLogix 5580 controllers.
The Minimum Capture (MINC) instruction retains the minimum value of the input over time and allows the user to re-establish a minimum as needed.
Available Languages
Ladder Diagram
This instruction is not available in ladder diagram.
Function Block
MINC_FBD_avail_v31
Structured Text
MINC(MINC_tag);
Operands
Function Block
Operand
Type
Format
Description
MINC tag
MINIMUM_CAPTURE
structure
MINC structure
MINIMUM_CAPTURE Structure
Input Parameter
Data Type
Description
EnableIn
BOOL
Enable input. If cleared, the instruction does not execute and outputs are not updated.
Default is set.
In
REAL
The analog signal input to the instruction.
Valid = any float
Default = 0.0
Reset
BOOL
Request to reset control algorithm. The instruction sets Out = ResetValue as long as Reset is set.
Default is cleared.
ResetValue
REAL
The reset value for the instruction. The instruction sets Out = ResetValue as long as Reset is set.
Valid = any float
Default = 0.0
Output Parameter
Data Type
Description
EnableOut
BOOL
Enable output.
Out
REAL
The calculated output of the algorithm.
Structured Text
Operand
Type
Format
Description
MINC tag
MINIMUM _CAPTURE
structure
MINC structure
See Structured Text Syntax for more information on the syntax of expressions within structured text.
Description
The MINC instruction executes this algorithm:
Condition
Action
Reset is set
LastMinimum = ResetValue
Out = ResetValue
Reset is cleared
If In < LastMinimum then update LastMinimum.
Out = LastMinimum.
Affects Math Status Flags
No
Major/Minor Faults
None specific to this instruction. See Common Attributes for operand-related faults.
Execution
Function Block
Condition/State
Action Taken
Prescan
EnableIn and EnableOut bits are cleared to false.
Tag.EnableIn is false
EnableIn and EnableOut bits are cleared to false.
Tag.EnableIn is true
EnableIn and EnableOut bits are set to true.
The instruction executes.
Instruction first run
N/A
Instruction first scan
Set request to initialize the Maximum value with the current input.
Postscan
EnableIn and EnableOut bits are cleared to false.
Structured Text
Condition/State
Action Taken
Prescan
See Prescan in the Function Block table.
Normal Execution
See Tag.EnableIn is true in the Function Block table.
Postscan
See Postscan in the Function Block table.
Examples
If Reset is set, the instruction set Out=ResetValue. If Reset is cleared, the instruction set Out=In when In < LastMinimum. Otherwise, the instruction sets Out= LastMinimum.
Function Block
MINC_FBD_ex_v31
Structured Text
MINCTag.In := input_value;
MINCTag.Reset := reset_input;
MINCTag.ResetValue := reset_value;
MINC(MINCTag);
result := MINCTag.Out;
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