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

2 Instruction Descriptions
Additional Information
When you calculate real numbers, use the CheckReal instruction (page 2-237) to see if Out is positive
infinity, negative infinity, or nonnumeric data.
Precautions for Correct Use
• Out can have a different data type than the subtraction result. However, the data type of Out must
include the valid range of the data type of the subtraction result. Otherwise, a building error will occur.
Refer to Data Type Ranking Table and Casting Rules in the NJ/NX-series CPU Unit Software User's
Manual (Cat. No. W501) or NY-series Industrial Panel PC / Industrial Box PC Software User's Man-
ual (Cat. No. W558) for the including relationship on data types.
• An error will not occur even if an underflow or overflow occurs in the subtraction.
• If an underflow or overflow occurs in subtraction, 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.
• Subtraction results of positive or negative infinity are handled as follows for real number values.
Subtraction
+∞
minus number
+∞
Number minus
−∞
minus number
−∞
Number minus
+∞ +∞
minus
−∞
+∞
minus
−∞
+∞
minus
−∞ −∞
minus
• If the value of In1 or In2 is nonnumeric data, the value of the subtraction result is nonnumeric data.
2-176
Subtraction result
+∞
−∞
−∞
+∞
Nonnumeric data
+∞
−∞
Nonnumeric data

NY-series Instructions Reference Manual (W560)