Upper/Lower Limit Control - Mitsubishi Electric MELSEC-Q/L Programming Manual

Upper/Lower limit control

LIMITATION(_E)
High
Basic
Process
performance
Structured ladder/FBD
LIMITATION_E
EN ENO
s1
s2
s3
The following function(s) can go in the dotted squares.
LIMITATION, LIMITATION_E
■Argument
Input/output
argument
Input argument
Output argument
Processing details
■Operation processing
• Selects the value to be output among the bit, word (signed), double word (signed), word (unsigned)/16-bit string, double
word (unsigned)/32-bit string, or single-precision real type, double-precision real, string, or time type data input to (s1), (s2),
and (s3) according to their values, and outputs the operation result from (d) in the same data type as that of (s1) to (s3).
When the input value of (s2) > the input value of (s3), outputs the input value (s3) from (d).
When the input value of (s2) < the input value of (s1), outputs the input value (s1) from (d).
When the input value of (s1)  the input value of (s2)  the input value of (s3), outputs the input value of (s2) from (d).
Ex.
Word (signed) type data
s1 -100
Word (signed) type
s2
120
Word (signed) type
s3
100
Word (signed) type
• The values to be input to (s1), (s2), and (s3) are bit, word (signed), double word (signed), word (unsigned)/16-bit string,
double word (unsigned)/32-bit string, single-precision real, double-precision real, string, or time type data. (the input value
of (s1) < the input value of (s3))
• Rounding error may occur when specifying single-precision real or double-precision real type data to (s1), (s2), or (s3) by
programming tool.
5 APPLICATION FUNCTIONS
148
5.5 Standard Selection Functions
Redundant Universal LCPU
ST
ENO:=
LIMITATION_E
d
Name Description
EN Executing condition (TRUE: Execution, FALSE:
Stop)
s1(_MN) Lower limit value (minimum output limit value)
s2(_IN) Input controlled by the upper/lower limit control
s3(_MX) Upper limit value (maximum output limit value)
ENO Execution result (TRUE: Normal, FALSE: Error)
d Output
d
LIMITATION
100
_MN OUT
_IN
Word (signed) type
_MX
(EN, s1, s2, s3, d);
Output value
MN input value
MX input value
Data type
Bit
ANY_SIMPLE
ANY_SIMPLE
ANY_SIMPLE
Bit
ANY_SIMPLE
Input value