Receiving Complete Flag [M8123] - Mitsubishi FX3U-USB-BD User Manual

FX Series PLC User's Manual - Data Communication Edition
Non-Protocol Communication (RS/RS2 Instruction)

12.2.5 Receiving complete flag [M8123]

This device turns ON when receiving is completed.
1. Detailed contents
This device turns ON when receiving is completed.
Receiving is completed in one of the following three conditions.
• When the PLC receives the amount of receive data specified by RS instruction
• When "terminator provided" is selected in the communication format, and the PLC receives the code set in
the terminator
• When data receiving is suspended and the PLC does not receive the next set of data within the time set in
the time-out time setting device
When the receiving complete flag turns ON, transfer the received data to another storage destination, and
then set this flag to OFF.
When this flag is set to OFF, the PLC waits to receive.
2. Cautions on use
When RS instruction is driven while the amount of received data is set to "0", the PLC does not wait to
receive. In such a case, set the amount of received data to "1" or more, set the receiving complete flag to ON,
and then set it to OFF.
12.2.6 Carrier detection flag [M8124]
This device turns ON and OFF in synchronization with the CD (DCD) signal.
1. Detailed contents
The CD (DCD) signal (channel receiving carrier detection) turns ON when the modem line is established.
While the carrier detection flag is OFF, the dial number can be sent.
While the carrier detection flag is ON, data can be sent and received.
12.2.7 Time-out check flag [M8129]
This device turns ON when data receiving is suspended, and the next set of receive data is not given within
the time set by the time-out time setting device.
1. Detailed contents
This device turns ON when data receiving is suspended and the next set of receive data is not given within
the time set by the time-out time setting device. The receiving complete flag also turns ON.
The time-out check flag turns OFF when the PLC waits to receive.
Using this function, the PLC can receive data from equipment where the amount of send data varies without
the terminator.
Receiving
Time-out check flag
M8129
Receiving complete
M8123
F-86
Receive data is
suspended.
Data
D8129
× 10 ms
ON
ON
12.2 Details of related devices (RS instruction)
Set to OFF in sequence program.
12 Related Data