Mitsubishi Electric QJ71C24N User Manual page 197

7 DATA COMMUNICATION USING THE BIDIRECTIONAL PROTOCOL
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1) Starts the local station programmable controller.
The setting values for GX Developer are stored in the Q series C24.
2) Inputs the user data transmission instruction signal.
3) Executes the BIDOUT instruction after storing the transmission data and the
control data for the BIDOUT instruction in the device.
Data is sent when the BIDOUT instruction is executed.
4) A response message for the data transmission (for normal completion: ACK
message; for abnormal completion: NAK message) is received.
5) When the response is received, the Q series C24 transmission processing
completes and the device that has completed the BIDOUT instruction turns ON.
When the BIDOUT instruction ends abnormally due to the reception of an NAK
message, the complete device +1 (abnormal completion signal) turns ON and the
error code is stored in the control data completion status (S1+1).
(Program example)
When Q series C24 I/O signals are from X/Y00 to X/Y1F:
MELSEC-Q
Transmission command is converted to pulse.
Transmission data is stored.
Designate the number of the interface (CH
that will send the data.
Clear the transmission result storage device
to 0.
Designate the transmission data count in word
units. (Designate K10 when the unit is bytes.)
The transmission data stored in the
designated device is sent.
After the BIDOUT instruction is executed,
the user designated transmission complete
signal (M1) turns ON for one scan.
Storing the transmission data and writing the
transmission data count in the buffer memory,
and issuing a transmission request to the Q
series C24 are all executed by the
programmable controller CPU.
The completion flag is reset by the external
command.
)
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