Mitsubishi Electric MELSEC FX Series User Manual page 111

FX communication
4 ) Use normal mode 2 of control line (FX, FX
RS instruction
driving
Send data
SD (TXD)
Send request
M8122
Send wait
flag M8121
ER(DTR)
DR(DSR)
Receive data
RD (RXD)
Receive
completion
M8123
*1 Please turn OFF ER (DTR) of DR (DSR) later.
*2 When the data is sent, please turn OFF DR (DSR). When it is turned ON, the next data cannot
be communicated.
*3 When sending data to the programmable controller, please check to turn OFF the ER (DTR)
signal.
*4 Reset using a program. When it is turned ON, the next data cannot be received.
*5 This period should be longer than 2 scan times or more.
OFF ON
Data 1
OFF ON
Check OFF
OFF ON
OFF ON *1
*5
Check
OFF
*3
only)
2C
Data 3
ON
*2
Data 2
OFF ON *4
RS instruction 9
*1
9-9
9