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FX3S/FX3G/FX3GC/FX3U/FX3UC Series
Programming Manual - Basic & Applied Instruction Edition
28 Data Comparison – FNC220 to FNC249
28.1 FNC224~230 – LD =, >, <, <>, <=, >= / Data Comparison
21
FNC160-FNC169
Real Time Clock
Control
22
FNC170-FNC179
External Device
23
FNC180
Alternate
Instructions
24
FNC181-FNC189
Others
25
FNC190-FNC199
Block Data
Operation
26
FNC200-FNC209
Character String
Control
27
FNC210-FNC219
Data
Operation 3
28
FNC220-FNC249
Data
Comparison
29
FNC250-FNC269
Data Table
Operation
30
FNC270-FNC276
Ex-Device
Explanation of function and operation
FNC224 to FNC230 are data comparison instructions connected to bus lines.
The contents of are compared with the contents of in binary format, and a contact becomes conductive
(ON) or non-conductive (OFF) depending on the comparison result.
Cautions
1. Negative value
When the most significant bit is "1" in the data stored in or , it is regarded as a negative value in
comparison.
• In the 16-bit operation: bit 15
• In the 32-bit operation: bit 31
2. When using 32-bit counters (including 32-bit high-speed counters)
Make sure to execute the 32-bit operation (such as "LDD=", "LDD>" and "LDD<") when comparing 32-bit counters
(C200 to C255).
If a 32-bit counter is specified in the 16-bit operation (such as "LD=", "LD>" and "LD<"), a program error or operation
error will occur.
3. Programming of data comparison instructions
When programming in GX Works2 and GX Developer, symbols "≤" and "≥" cannot be input.
Separate "≤" into "<" and "=", and separate "≥" into ">" and "=".
<Input example for 16-bit operation>
<Input example for 32-bit operation>
Program example
FNC No. 16-bit instruction 32-bit instruction ON condition OFF condition
224 LD= LDD=
= ≠
225 LD> LDD>
> <=
226 LD< LDD<
< >=
228 LD<> LDD<>
≠ =
229 LD<= LDD<=
<= >
230 LD>= LDD>=
>= <
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
S
1
S
2
S
1
S
2
C10
FNC224
LD=
K200
S1 S2
Y10
K-30
FNC225
LD>
D200
X001
SET
Y11
C200
FNC225
LDD>
K678493 M50
M3
When the current value of the counter C10 is "200", Y010
is driven.
When the contents of D200 are "-29" or higher and X001 is
ON, Y011 is set.
When the contents of the counter C200 are less than
"K678,493" or when M3 turns ON, M50 is driven.