661
FX3S/FX3G/FX3GC/FX3U/FX3UC Series
Programming Manual - Basic & Applied Instruction Edition
29 Data Table Operation – FNC250 to FNC269
29.1 FNC256 – LIMIT / Limit Control
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
29.1 FNC256 – LIMIT / Limit Control
Outline
This instruction provides the upper limit value and lower limit value for an input numeric value, and controls the output
value using these limit values.
1. Instruction format
2. Set data
3. Applicable devices
Explanation of function and operation
1. 16-bit operation (LIMIT and LIMITP)
Depending on how the input value (16-bit binary value) specified by compares to the range between
and , the output value is controlled.
The output value is controlled as shown below:
• When controlling the output value using only the upper limit value, set “-32768” to the lower limit value specified in
.
Operand Type Description Data Type
Lower limit value (minimum output value)
16- or 32-bit binary
Upper limit value (maximum output value)
Input value controlled by the upper and lower limit values
Head device number storing the output value controlled by the upper and lower limit
values
Oper-
and
Type
Bit Devices Word Devices Others
System User Digit Specification System User
Special
Unit
Index
Con-
stant
Real
Number
Charac-
ter String
Pointer
XYMTCSD
.b KnX KnY KnM KnS T C D R
U\G
V Z Modify K H E "
"P
P
FNC 256
LIMIT
D
Mnemonic Operation Condition
16-bit Instruction
9 steps
LIMIT
LIMITP
Mnemonic Operation Condition
Continuous
Operation
Pulse (Single)
Operation
32-bit Instruction
17 steps
DLIMIT
DLIMITP
Continuous
Operation
Pulse (Single)
Operation
S
1
S
2
S
3
D
S
1
S
2
S
3
D
S
3
S
1
S
2
D
FNC256
LIMIT
S
1
S
2
D S
3
Input
value
Output
value
Input
value
Output
value
()
()
Command
input
In the case of “ Lower limit value > Input value” .... Lower limit value → Output value
In the case of “ Upper limit value < Input value” .... Upper limit value → Output value
In the case of “ Lower limit value ≤ Input value ≤ Upper limit value”
S
1
S
3
S
1
D
S
2
S
3
S
2
D
S
3
S
2
S
1
D
S
2
S
3
S
1
Specified
Specified
.... Input value → Output value
S
3
D
S
1