Mitsubishi FX3U-USB-BD User Manual page 533

FX Series PLC User's Manual - Data Communication Edition
Non-Protocol Communication (RS/RS2 Instruction)
8. Creating Programs (RS2 Instruction)
This chapter explains how to create programs for non-protocol communication using RS2 instruction and how
such programs operate.
RS2 instruction is supported only in FX
RS2 instruction has the following additional functions which are not provided in the RS instruction:
1) Up to 4 characters (bytes) can be specified as the header and terminator.
2) The sum check can be added automatically.
3) The communication port (channel) can be specified.
8.1 Checking Contents of Related Devices
The tables below show devices used in non-protocol communication using RS2 instruction.
1. Bit devices
Device
*1
ch1 ch2
ch0
M8062 M8063 M8438
M8371 M8401 M8421 Sending wait flag
M8372 M8402 M8422 Sending request
M8373 M8403 M8423 Receiving complete flag
— M8404 M8424 Carrier detection flag
*2 — M8405 M8425 Data set ready (DSR) flag
M8379 M8409 M8429 Time-out check flag
R: Read only
W: Write only
R/W: Read or Write
*1. Ch0 is supported only in FX
*2. Available in Ver.2.30 or later of FX
, FX
3G 3U
Name
This device turns ON when a communication error occurs.
Serial communication When this device (serial communication error) turns ON,
error D8062, D8063 or D8438 stores the corresponding error
code.
This device remains ON while the PLC is waiting to send.
When this device is set to ON, the PLC starts to send.
This device turns ON when receiving is completed.
While this device (receiving complete flag) is ON, the PLC
cannot receive any receive data.
This device turns ON in synchronization with the CD (DCD)
signal.
This device turns ON in synchronization with the DR (DSR)
signal.
This device turns ON when data receiving is suspended and
the next set of receive data is not given within the time set by
the time-out time setting device.
PLCs.
3G
or FX
3U
8 Creating Programs (RS2 Instruction)
and FX PLCs.
3UC
Description
PLC. Available in all FX
3UC
8.1 Checking Contents of Related Devices
R/W
R/W
R/W
R/W
PLCs.
3G
F-53
A
B
C
D
E
R
R
F
R
R
G
H
I
Apx.