471
FX3G/FX3U/FX3UC Series Programmable Controllers
Programming Manual - Basic & Applied Instruction Edition
16 External FX Device – FNC 80 to FNC 89
16.8 FNC 87 – RS2 / Serial Communication 2
11
FNC30-FNC39
Rotation and
Shift
12
FNC40-FNC49
Data Operation
13
FNC50-FNC59
High Speed
Processing
14
FMC60-FNC69
Handy
Instruction
15
FNC70-FNC79
External FX I/O
Device
16
FNC80-FNC89
External FX
Device
17
FNC100-FNC109
Data
Transfer 2
18
FNC110-FNC139
Floating Point
19
FNC140-FNC149
Data
Operation 2
20
FNC150-FNC159
Positioning
Control
16.8 FNC 87 – RS2 / Serial Communication 2
Outline
This instruction sends and receives data in no-protocol communication by way of serial ports in accordance with
RS-232C or RS-485 provided in the main unit.
In FX
3G PLCs, data can be sent and received in no-protocol communication by way of the standard built-in port
(RS-422).
1. Instruction format
2. Set data
*1. Ch2 is not available in 14-point and 24-point type FX3G PLCs.
Ch0 is available only in FX
3G PLCs.
3. Applicable devices
Explanation of function and operation
1. 16-bit operation (RS2)
This instruction sends and receives data in no-protocol communication by way of serial ports in accordance with
RS-232C or RS-485 provided in the main unit.
→ For detailed explanation, refer to the Data Communication Edition.
Operand type Description Data type
Head device of data registers storing data to be sent
16-bit binary or
character string
m Number of bytes of data to be sent [setting range: 0 to 4,096] 16-bit binary
Head device of data registers storing received data when receiving is completed
16-bit binary or
character string
n Number of bytes to be received [setting range: 0 to 4,096] 16-bit binary
n1
Used channel number [contents of setting: K0 = ch 0, K1 = ch 1, K2 = ch 2]
*1
16-bit binary
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
33 3
m 33 33
33 3
n 33 33
n1 33
FNC 87
RS2
−
Mnemonic Operation Condition
16-bit Instruction
11 steps RS2
Mnemonic Operation Condition
Continuous
Operation
32-bit Instruction
S
1
S
D
S
1
S
S
2
D
FNC 87
RS2
mS
Command
input
D
n n1