Mitsubishi MELSEC Q Series, Programming Manual

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6.1 Comparison Operation Instructions
6.1.3 Floating-point data comparison (single precision)
6-9
6
BA
S
IC
INSTRUCTIONS
E=,
E<>,
E
<=,
E<,
E>=,
E>
E=, E<>, E<=, E<, E>=, E>
(2) The results of the comparison operations for each instruction are as follows.
Note that when using the E= instruction, the values of operation result may not
be equal depending on the error.
O p erat i on E rror
In any of the following cases, an operation error occurs, the error flag (SM0) is turned ON, and
the corresponding error code is stored to SD0.
• The value of the specified device is 0. *
1
(For High Performance model QCPU only) (Error code: 4100)
*1: There are CPU modules that do not result in any operation error when 0 is specified. For details, refer to
Section 3.4.4.
• The value of the specified device is outside the following range. (For Universal model
QCPU only)
0, 2
- 126
| value of the specified device | < 2
128
(Error code: 4140)
• The value of the specified device is - 0, unnormalized number, nonnumeric or ±
∞
.
(For Universal model QCPU only) (Error code: 4140)
Program E xam pl e
(1) In the following program, the value in Var_D0 is compared with the value in Var_D3 and Y33
turns ON when the value in Var_D0 and the value in Var_D3 are matched.
[Structured ladder]
Instruction
symbol in
Condition Comparison result
Instruction
symbol in
Condition Comparison result
E=
=
Conduction state
E=
Non-conduction
state
E<> E<>
=
E<= E<=
>
E<
<
E<
E>= E>=
<
E>
>
E>
s 1 s 2 s 1
s 2
s 1
s 2
s 1
s 2
s 1
s 2
s 1
s 2
s 1
s 2
s 1
s 2
s 1
s 2
s 1
s 2
s 1
s 2
s 1
s 2