F-54
FX Series PLC User's Manual - Data Communication Edition
Non-Protocol Communication (RS/RS2 Instruction)
6 Creating Programs (RS Instruction)
6.3 Operation of Control Line
6.3.2
FX
2N
(Ver. 2.00 or later), FX
2NC
, FX
3S
, FX
3G
, FX
3GC
, FX
3U
and FX
3UC
PLCs
FX
2N
PLCs Ver. 2.00 or later, and FX
2NC
, FX
3S
, FX
3G
, FX
3GC
, FX
3U
and FX
3UC
PLCs execute full-duplex,
bidirectional communication. When executing half-duplex, bidirectional communication, pay attention not to
set the sending request to ON while receiving. If the sending request is set to ON, the PLC starts to send. As
a result, the external equipment may not be able to receive data, and the sent and received data may be
destroyed.
In full-duplex, bidirectional communication, the sending wait flag M8121 does not turn ON.
In FX
3S
, FX
3G
, FX
3GC
, FX
3U
and FX
3UC
PLCs, however, the sending wait flag M8121 remains ON while the
DR (DSR) is OFF, the PLC waits to send, and the control line is in the standard mode or interlink mode.
1. Without control line
2. When the control line is in the standard mode
Use this mode when only sending or receiving.
The control line and transfer sequence are equivalent to those in FX
2N
PLCs (before Ver. 2.00). Refer to
Subsection 6.3.1.
3. When the control line is in the modem mode
Reset it in a sequence program.
While it remains ON, the PLC cannot receive the next set of data.
RS
instruction
driving
SD (TXD)
Send data
OFF ON
OFF
ON
Sending
request
M8122
Receiving
complete
M8123
OFF
ON
ON
Receiving wait status is
started.
RD (RXD)
Receive data
Message
1
Message
3
Message
5
Message 4
Message
2
Reset it in a sequence program.
While it remains ON, the PLC cannot receive the next set of data.
OFF
OFF
ON
ON
OFF
ON
RS
instruction
driving
SD (TXD)
Send data
ER (DTR)
ON
Receiving
complete
M8123
OFF
ON
RD (RXD)
Receive data
OFF
ON
Sending
request
M8122
DR (DSR)
Message
1
Message 4
Message 3
Message 2
Summary of Contents for FX-485ADP
Page 2: ......
Page 120: ...B 2 FX Series PLC User s Manual Data Communication Edition N N Network ...
Page 188: ...C 2 FX Series PLC User s Manual Data Communication Edition Parallel Link ...
Page 244: ...D 2 FX Series PLC User s Manual Data Communication Edition Computer Link ...
Page 344: ...E 2 FX Series PLC User s Manual Data Communication Edition Inverter Communication ...
Page 700: ...H 2 FX Series PLC User s Manual Data Communication Edition Programming Communication ...
Page 752: ...I 2 FX Series PLC User s Manual Data Communication Edition Remote Maintenance ...
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