Mitsubishi FX3U-USB-BD User Manual page 548

FX Series PLC User's Manual - Data Communication Edition
Non-Protocol Communication (RS/RS2 Instruction)
4. When the control line is in the interlink mode
RS2
instruction
OFF ON
driving
SD (TXD)
Send data
Sending
request
M8402
DR (DSR)
RD (RXD)
Receive data
Time-out
check
flag M8409
Receiving
complete
M8403
ER (DTR)
*1. On the external equipment side, set the DR (DSR) signal to ON when the external equipment is ready
to receive.
The FX
3G
request turn ON.
*2. In the interlink mode, the PLC sets the ER (DTR) signal to OFF 30 characters before reaching the
specified amount of received data, and asks the external equipment to stop sending. After that, the
PLC can only receive up to 30 characters. In this case, temporarily stop sending, and then send the
remaining data after the ER (DTR) signal turns ON again.
When sending is stopped, the PLC finishes receiving after the time-out time setting is reached.
When sending is not stopped, the PLC finishes receiving after it has received the final send data or 30
characters. Accordingly, make sure that the number of receive characters are "30 + α".
F-68
Message
2
ON
OFF ON
*1
Message
1
OFF ON
ON OFF
/FX /FX PLC sends the send data when both the DR (DSR) signal and the sending
3U 3UC
Message
4
OFF
*1
Up to 30 characters can be
received.
Message 3
Time-out
time setting
D8409 × 10 ms
Reset it in a sequence program.
While it remains ON, the PLC cannot receive the next set of data.
8 Creating Programs (RS2 Instruction)
8.3 Operation of Control Line
Message
4
*1
*2
Message
3
ON ON