How To Use Rs Instruction - Mitsubishi Electric FX3U-232-BD User Manual

FX Series PLC User's Manual - Data Communication Edition
Non-Protocol Communication (RS/RS2 Instruction)
6.2

How to Use RS Instruction

This section explains the function, operation and programming method of RS instruction.
1. 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 V Z Modify K H
S
m
D
n
: Applicable only in FX
m, n: 0 to 4096 points in FX
(However, "m + n" should not be more than 8000 points in FX
0 to 256 points in FX
2. Program example
M0
Head device storing send data
Number of send data: 0 to 4096 points
(0 to 256 points in FX
FX , FX and FX
1S 1N
6.2.1 Applicable frames
Message frames used in communication can be selected by setting the communication format.
The table below shows the message frames applicable to the RS instruction.
1
2
3
4
1. Header
When "header provided" is selected in the communication format settings, the lowest-order byte of D8124 is
used.
When data is sent, the lowest-order byte of D8124 is added at the head of the specified send data to be sent.
When data is received, receiving begins when the data on lowest-order byte of D8124 is received.
2. Terminator
When "terminator provided" is selected in the communication format settings, the lowest-order byte of D8125
is used.
When data is sent, the lowest-order byte of D8125 is added at the end of the specified send data.
When data is received, receiving is completed
*1. Receiving is completed also when the amount of received data specified by the RS instruction is
received or when the receiving of data is suspended and the next set of data is not executed within the
timeout time set by D8129.
F-46
Digit Specification
, FX , FX , FX
3G 3GC 3U
, FX , FX
2N 2NC
(FX), FX , FX
2 2C
S 
FNC 80
D100
RS
(FX), FX , FX ,
2 2C 0N
PLCs)
1NC
Data
Data
Header Data
Header Data
Word Devices
Special
System/User
Unit
 
 
 
 
PLCs.
3UC
, FX , FX , FX and FX
3S 3G 3GC 3U
, FX , FX and FX
0N 1S 1N 1NC
m D  n
D0 D200 D1
Amount of received data: 0 to 4096 points
(0 to 256 points in FX
FX
Head device storing receive data
Terminator
Terminator
*1
when the data on lowest-order byte of D8125 is received.
6 Creating Programs (RS Instruction)
6.2 How to Use RS Instruction
Others
Con- Real
Index
stant Number
E

 

 
PLCs
3UC
and FX PLCs.)
2N 2NC
PLCs
(FX), FX
2
, FX and FX PLCs)
1S 1N 1NC
Header: Not provided
Terminator: Not provided
Header: Not provided
Terminator: Provided
Header: Provided
Terminator: Not provided
Header: Provided
Terminator: Provided
Charac-
Pointer
ter String
"" P
, FX ,
2C 0N