Fnc 87 - Rs2 / Serial Communication 2 - Mitsubishi Electric MELSEC FX3U Programming Manual

FX /FX /FX Series Programmable Controllers
3G 3U 3UC
Programming Manual - Basic & Applied Instruction Edition
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 PLCs, data can be sent and received in no-protocol communication by way of the standard built-in
3G
port (RS-422).
1. Instruction format
FNC 87
RS2
2. Set data
Operand type
S
S
1
m
D
n
n1
*1. Ch2 is not available in 14-point and 24-point type FX
Ch0 is available only in FX
3. Applicable devices
Bit Devices
Oper-
and System User
Type
X Y M T C S D .b KnX KnY KnM KnS T C D R U \G
S
S
1
m
S D
2
n
n1
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.
Command
input
FNC 87
RS2
492
Mnemonic
16-bit Instruction
11 steps RS2
Head device of data registers storing data to be sent
Number of bytes of data to be sent [setting range: 0 to 4,096]
Head device of data registers storing received data when receiving is completed
Number of bytes to be received [setting range: 0 to 4,096]
Used channel number [contents of setting: K0 = ch 0, K1 = ch 1, K2 = ch 2]
PLCs.
3G
Digit Specification
→ For detailed explanation, refer to the Data Communication Edition.
S m D
16 External FX Device – FNC 80 to FNC 89
16.8 FNC 87 – RS2 / Serial Communication 2
Operation Condition
32-bit Instruction
Continuous
Operation
Description
PLCs.
3G
Word Devices
Special
System User
Unit
V Z Modify K H
n n1
Mnemonic Operation Condition
−
Data type
16-bit binary or
character string
16-bit binary
16-bit binary or
character string
16-bit binary
*1
16-bit binary
Others
Con- Real Charac-
Index
stant Number ter String
E " "
Pointer
P