428
FX
3G
/FX
3U
/FX
3UC
Series Programmable Controllers
Programming Manual - Basic & Applied Instruction Edition
14 Handy Instruction – FNC 60 to FNC 69
14.7 FNC 66 – ALT / Alternate State
14.7
FNC 66 – ALT / Alternate State
Outline
This instruction alternates a bit device (from ON to OFF or from OFF to ON) when the input turns ON.
1. Instruction format
2. Set data
3. Applicable devices
S
: "D
.b" is available only in FX
3U
and FX
3UC
PLCs. However, index modifiers (V and Z) are not available.
Explanation of function and operation
1. 16-bit operation (ALT and ALTP)
Alternating output (1-step)
Every time the command input turns ON from OFF, a bit device specified in
is alternated (from ON to
OFF or from OFF to ON).
Dividing output (by 2-step alternating output)
Multi-step dividing outputs are achieved by combination of two or more ALTP instructions.
Operand type
Description
Data type
Bit device number whose output is alternated
Bit
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
X Y M T C S D
.b KnX KnY KnM KnS T C D R U
\G
V Z Modify K H
E
"
"
P
3 3
3
S
3
P
FNC 66
ALT
−
−
Mnemonic
Operation Condition
16-bit Instruction
3 steps ALT
ALTP
Mnemonic
Operation Condition
Continuous
Operation
Pulse (Single)
Operation
32-bit Instruction
D
S
2
D
D
1
D
Command
input
FNC 66
ALTP
D
Command input
D
ON
ON
ON
ON
ON
1st step
2nd step
Command
input
ON
ON
ON
ON
ON
ON
ON
Command
input
FNC 66
ALTP
M0
D
FNC 66
ALTP
M1
D
Specify a same device
M0
D
M0
D
M1