2 - 69
2 Standard Functions
NX-series Safety Control Unit Instructions Reference Manual (Z931)
Comparison Instructions
2
LT, LE, GT, and GE
These functions compare the values of two variables, In1 and In2.
The output value Out is shown below for each instruction.
LT: If In1 is less than In2, the result is TRUE. Otherwise the result is FALSE.
LE: If In1 is less than or equal to In2, the result is TRUE. Otherwise the result is FALSE.
GT: If In1 is greater than In2, the result is TRUE. Otherwise the result is FALSE.
GE: If In1 is greater than or equal to In2, the result is TRUE. Otherwise the result is FALSE.
The relationship between values with data types that are integers or durations are determined as given
in the following table.
• You can compare In1 and In2 even if they have different data types, such as a safety data type and a
standard data type, as long as the notations and sizes of the data types are the same. You cannot
compare data with data types that have different notations or sizes, such as WORD and INT. You can
compare integer data, such as INT data with SAFEINT data and DINT data with SAFEDINT data.
• The input condition depends on whether the output is safety data or standard data. If the condition is
not met, a building error will occur. If you set a safety data type variable for the output terminal, set a
safety data type variable for the two input terminals as well.
If you set a standard data type variable for the output terminal, you can set either a safety data type
variable or a standard data type variable for the input terminal.
Function
Additional Information
Data types Relationship
INT, SAFEINT, DINT, or SAFEDINT The sign is included in the comparison.
TIME or SAFETIME The values of the days, hours, minutes, seconds, and millisec-
onds are compared.
Precautions for Correct Use
To Next Page
Loading...
