181
FX
3G
/FX
3U
/FX
3UC
Series Programmable Controllers
Programming Manual - Basic & Applied Instruction Edition
7 Basic Instruction
7.1 LD, LDI
1
Introdu
ction
2
Ov
ervi
ew
3
Instruction
Li
st
4
D
evices
in Det
ail
5
Specifi
ed the
De
vice
&
C
onst
ant
6
Bef
ore
Pr
og
ra
mmi
ng
7
Bas
ic
Instruction
8
FN
C00-FN
C0
9
Program Fl
ow
9
FNC
10-FN
C19
Mov
e & Com
pare
10
FNC
20-FNC
29
Arith. & Lo
gi
c
Operati
on
7.1
LD, LDI
Outline
LD and LDI instructions are contacts connected to bus lines.
When combined with ANB instruction described later, LD and LDI instructions can be used for the start of branches.
1. Instruction format
→
For the number of instruction steps, refer to Section 7.15.
2. Applicable devices
S
1: Special auxiliary relays (M) and 32-bit counters (C) cannot be indexed with index registers (V and Z).
S
2: State relays (S) cannot be indexed with index registers (V and Z).
S
3: "D
.b" is available only in FX
3U
and FX
3UC
PLCs. However, index modifiers (V and Z) are not available.
S
4: This function is supported only in FX
3U
/FX
3UC
PLCs.
Explanation of function and operation
1. LD instruction (initial logical operation, NO contact type)
Instruc-
tion
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
LD
3 3
S
1
3
S
1
S
2
S
3
S
4
LDI
3 3
S
1
3
S
1
S
2
S
3
S
4
LD
Load
Basic Instruction
LD
−
Continuous
Operation
Pulse (Single)
Operation
Mnemonic
Operation Condition
LDI
Load
Inverse
Basic Instruction
LDI
−
Continuous
Operation
Pulse (Single)
Operation
Mnemonic
Operation Condition
X000
Y000
LD instruction
Circuit program
List program
LD
OUT
0000
0001
X000
Y000
Connection to bus line
ON
ON
X000
ON
ON
Y000
Timing chart
Bus line