Mitsubishi Electric MELSEC FX Series - Page 111

FX communication
RS instruction 9
9-9
9
4 ) Use normal mode 2 of control line (FX, FX
2C
only)
*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.
Data 1
RS instruction
driving
Send wait
flag M8121
Send data
SD (TXD)
OFF ON
Data 3
Data 2
OFF ON
Send request
M8122
Receive data
RD (RXD)
Receive
completion
M8123
OFF ON
ON
ONOFF
OFF
ER(DTR)
DR(DSR)
*4
*5
*1
*2
*3
*1
Check
OFF
ON
Check OFF