Ny-Series Instructions Reference Manual (W560 - Omron NY532-5400 Reference Manual

Additional Information
• Use the EXP instruction (page 2-209) to find powers of base e.
• Use the CheckReal instruction (page 2-237) to see if Out is positive infinity, negative infinity, or non-
numeric data.
Precautions for Correct Use
• If the absolute value of the calculation result is lower than the minimum value for a real number, the
value of Out will be 0.
Example: (1.175494e−38)
• An error will not occur even if an underflow or overflow occurs in the calculation when the ** operator
is used.
• If an underflow or overflow occurs in the calculation when the ** operator is used, the calculation
result may not be as expected. Allow sufficient leeway in the sizes of the data types for input and
output parameters so that overflows and underflows do not occur.
• For the EXPT instruction and ** instruction of ladder diagrams and the EXPT function of ST, if you
pass an integer parameter to In, the data type is converted as follows:
Data type of parameter that is
passed to In
USINT, UINT, SINT, or INT
UDINT or DINT
ULINT or LINT
• When the ** operator is used, if you select the version 1.15 or earlier in the Select Device Area of the
Project Properties Dialog Box on the Sysmac Studio for an NX701 CPU Unit, NJ-series CPU Unit and
NY-series Controller, integer variables are calculated as real number variables even if they set as
operands.
If a rounding error is included in the result of calculations, the result may not be an intended value
because all values after the decimal point are truncated.
Use the EXPT and TO_** (Integer Conversion Group) instructions together to round values after the
decimal point.
Example) TO_INT (EXPT(X,Y))

NY-series Instructions Reference Manual (W560)

2
→ 0
Data type of In
REAL
LREAL
A building error will occur.
2 Instruction Descriptions
2
2-213