Omron CQM1H-SCB41 Operation Manual page 112

Using Protocol Macros
Waveform image for send/receive signals in 2-wire connection
When the Echoback Disable Mode Flag is ON, signal reception
will be disabled while the modem control RS signal is ON.
RS signal (PC side)
SD signal (PC side)
RD signal (PC side)
Echoback data receive data
When the Echoback Disable Mode
Flag is ON, this data is ignored.
Note The condition of the 20700 to 20707, 20711, and 20715 flags is also main-
tained during interruptions in the power supply.
When 20711 or 20715 (Forced Abort Bit for Port 1 or Port 2) is set to 1 (ON),
signals will not be sent or received.
Use a Programming Device to clear the flag, or use a ladder program to form
a circuit that sets these bits
ON during scan 1 at program start
25315
Send data
to 0 (OFF).
MOV
#0000
207
Section 5-7
Proper response receive
data
97