Mitsubishi Electric MELSEC iQ-F FX5 Programming Manual page 495

• The table below shows the related devices.
Device Name
SM700 Carry
SM8020 Zero
SM8021 Borrow
SM8022 Carry
Precautions
The same device number can be specified for (s1), (s2), and (d). In this case, note that the subtraction result changes in every
operation cycle when the continuous operation type instruction (DESUB) is used.
Operation error
Error code Description
(SD0/SD8067)
The specified device value is denormalized number, NaN (not a number), or .
3402H
Description
Condition
The absolute value of the operation result  2
The operation result is true "0".
(The mantissa part is "0").
The absolute value of the operation result < 2
The absolute value of the operation result  2
Operation
128
The value of (d) is the maximum value (2
numbers and the carry flag SM700 turns on.
The zero flag SM8020 turns on.
-126
The value of (d) is the minimum value (2
numbers and the borrow flag SM8021 turns on.
128
The value of (d) is the maximum value (2
numbers and the carry flag SM8022 turns on.
8 APPLICATION INSTRUCTION
8.9 Real Number Instruction
128
) of 32-bit real
-126
) of 32-bit real
128
) of 32-bit real
8
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