Short summary

Name	`LIMIT`
→POU type	→function
Category	IEC-block, Select
Conform to →IEC-standard	currently restricted (IEC demands data type `ANY_ELEMENTARY` for the inputs, hence the following data types are demanded as well: `LTIME`, `STRING`, `WSTRING`, `CHAR`, `WCHAR`, `LDATE_AND_TIME`, `LTIME_OF_DAY` and `LDATE`. Currently, these data types are not supported for the block.)
Graphical interface
Available since	version 1.22.0 (for logi.CAD 3)

Functionality

The block limits a value to defined limits (minimum and maximum value): MIN(MAX(IN, MN),MX)

You connect a value at input IN. If the value of IN exceeds the maximum value connected at input MX, the block returns the value of MX. If the value of IN is below the minimum value connected at input MN, the block returns the value of MN. If the value of IN is within the defined limits or it is equal to one of the limits, the block returns the value of IN.

Special cases (see under "Example for usage within ST-editor" ) : If the minimum value exceeds the maximum value, the block always returns the value of MX.

Inputs, return value

	Identifier	→Data type	Description
Inputs:	`MN`	`REAL`, `LREAL`, `USINT`, `UINT`, `UDINT`, `ULINT`, `SINT`, `INT`, `DINT`, `LINT`, `TIME`, `BOOL`, `BYTE`, `WORD`, `DWORD`, `LWORD`, `DATE_AND_TIME`, `DATE` or `TIME_OF_DAY`	minimum value
	`IN`	`REAL`, `LREAL`, `USINT`, `UINT`, `UDINT`, `ULINT`, `SINT`, `INT`, `DINT`, `LINT`, `TIME`, `BOOL`, `BYTE`, `WORD`, `DWORD`, `LWORD`, `DATE_AND_TIME`, `DATE` or `TIME_OF_DAY`	value
	`MX`	`REAL`, `LREAL`, `USINT`, `UINT`, `UDINT`, `ULINT`, `SINT`, `INT`, `DINT`, `LINT`, `TIME`, `BOOL`, `BYTE`, `WORD`, `DWORD`, `LWORD`, `DATE_AND_TIME`, `DATE` or `TIME_OF_DAY`	maximum value
Return value:	–	`REAL, LREAL, USINT, UINT, UDINT, ULINT, SINT, INT, DINT, LINT, TIME, BOOL, BYTE, WORD, DWORD, LWORD, DATE_AND_TIME, DATE or TIME_OF_DAY`

Input EN and output ENO are available when →calling the block. See "Execution control: EN, ENO" for information on input EN and output ENO.

Example for usage within ST-editor

PROGRAM Test
	VAR
		result1, result2, result3, result4 : INT;
	END_VAR
	result1 := LIMIT(MN := 5, IN := 99, MX := 100);       (* The variable 'result1' evaluates to '99'. *)
	result2 := LIMIT(MN := 5, IN := 2, MX := 100);        (* The variable 'result2' evaluates to '5'. *)
	result3 := LIMIT(MN := 5, IN := 105, MX := 100);      (* The variable 'result3' evaluates to '100'. *)
	result4 := LIMIT(MN := 100, IN := 2, MX := 5);        (* The variable 'result3' evaluates to '5'. Reason: value for 'MN' > value for 'MX' *)
END_PROGRAM

When creating your application within the ST-editor, enter a call of a block by typing the text as requested by the syntax or use Content Assist.