Mitsubishi Electric M800VW Series Programming Manual page 188

M800V/M80V Series PLC Programming Manual (1/2)
8 Function Instructions
8.1 Comparison Operation Instructions
ED=, ED<>, ED>, ED<=, ED<, ED>=: Floating-point data comparison (double precision)
Setting
Bit devices
data
X Y M L F
S1
S2
△ : S1 and S2 cannot be specified as constant at the same time.
[Instruction symbol] [Execution condition]
LD
AND
OR
 Setting data
Setting data
S1
Comparative data, or the first number of the device where comparative data is
stored
S2
 Functions
 Treats 64-bit floating-point real number from device designated by (S1) and 64-bit floating-point real number from device
designated by (S2) as an A contact, and performs comparison operation.
 The results of the comparison operations for the individual instructions are as follows:
Instruction sym-
Condition
bol in
ED= S1=S2
ED<>
S1 ≠ S2
ED> S1>S2
ED<= S1≤S2
ED< S1<S2
ED>= S1≥S2
 When setting input values from programming tools, rounding errors may occur.
For precautions when setting input values from programming tools, refer to "6.3.4 Single/Double-Precision Real Number
Data".
 Operation errors
 In the following cases, an arithmetic error occurs, the error flag (SM0) turns ON, and an error code is stored at SD0.
- The designated device value is not within the following range. (Error code: 35)
-1022
0, 2 ≤ | Designated device value | < 2
- The designated device value is "-0", unnormalized number, nonnumeric, or ± ∞ . (Error code: 35)
Usable devices
B SB T SM V T C
○ ○
○ ○
indicates the signs "ED=", "ED<>", "ED>", "ED<=", "ED<", "ED>=".
Meaning
Instruction sym-
Comparison oper-
ation result
bol in
Continuity ED=
ED<>
ED>
ED<=
ED<
ED>=
1024
Con-
Word devices
stant
D R/ZR W SW SD Z
○ ○ ○ ○ ○
○ ○ ○ ○ ○
S1
S1
S1
Comparison oper-
Condition
ation result
Non-continuity
S1 ≠ S2
S1=S2
S1≤S2
S1>S2
S1≥S2
S1<S2
167
Digit
Pointer designa- Index
tion
E P
△
○
△
S2
S2
S2
Data type
Real number
IB-1501667-B