Mitsubishi Electronics FX3G User Manual
697
FX
3S
/FX
3G
/FX
3GC
/FX
3U
/FX
3UC
Series
Programming Manual - Basic & Applied Instruction Edition
30 External Device Communication – FNC270 to FNC276
30.7 FNC276 - MODBUS Read/Write Instruction
21
FNC160
-F
NC1
69
69
R
eal
T
T
ime C
lock
C
ontrol
22
FNC17
0-F
NC
179
179
E
xternal D
evice
23
FNC
180
Alternate
Instructions
24
FN
C181-
FNC18
9
O
thers
25
FNC190
-F
NC1
99
99
Bl
oc
k D
ata
ata
Op
er
er
ation
26
FNC20
0-F
NC209
C
har
ac
te
r S
trin
g
Con
tro
tro
l
27
FNC2
10-
FNC21
10-
FNC21
9
Dat
a
a
Operati
on 3
28
FNC220
-F
NC2
49
49
Da
ta
C
omp
ari
ari
son
29
FNC25
0-F
N
C
269
D
ata T
abl
e
e
Operation
30
FNC2
70-
FNC276
FNC276
Ex
-Dev
ice
30.7
FNC276 - MODBUS Read/Write Instruction
Outline
This instruction allows the MODBUS Master to communicate (read/write data) with its associated Slaves.
→ For explanation of the instruction, refer to the MODBUS Communication Edition.
1. Instruction Format
2. Set Data
3. Applicable Devices
S1: Except special auxiliary relay (M) and special data register (D).
S2: Only available for FX
S2: Only available for FX
3G
/FX
3GC
/FX
3U
/FX
3UC
PLCs.
Explanation of function and operation
1. 16-bit operation (ADPRW)
Command Code
is operated on Slave Node
according to Parameters
,
, and
/
.
Use 0 as the Slave Node Address for Broadcast commands.
Operand Type
Description
Data Type
Slave Node Address (K0 to K32)
16-bit binary
Command Code
16-bit binary
Command Parameter depending on the Command Code (See Subsection 30.7.1)
16-bit binary
Command Parameter depending on the Command Code (See Subsection 30.7.1)
16-bit binary
/
Command Parameter depending on the Command Code (See Subsection 30.7.1)
Bit or 16-bit binary
Operand Type
Bit Devices
Word Devices
Others
System User
Digit Specification
System User
Special
Unit
Index
Con-
stant
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
S1 S2
S1 S2
S1 S2
S1 S2
/
S1
S1 S2
FNC 276
ADPRW
16-bit Instruction
11 steps
ADPRW
Continuous
Operation
Operation
Mnemonic Operation Condition
32-bit Instruction
Mnemonic Operation Condition
S
S
1
S
2
S
3
S
4
D
S
S
1
S
2
S
3
S
4
D
S
1
S
S
2
S
3
S
4
D
Command
input
FNC276
ADPRW
ADPRW
S
Slave
Node
Address
Command
code
/
Command Code Parameters
Command Parameters
depending on the
Command Code
Command Code
Slave Node Address
K0 to K32 (00H to 20H)
S
1
S
2
S
3
S
4
D