Mitsubishi MELSEC QJ71C24, Руководство пользователя

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MELSEC-Q
10 DEDICATED INSTRUCTIONS
(3) Whether a BIDIN instruction was completed normally can be checked by the
completion device ((D2)) or status display device at completion ((D2)+1).
(a) Completion device: Turns on at the END processing of the scan where the
BIDIN instruction is completed normally, and turns off at
the next END processing.
(b) Status display device at completion: Does not change when left off.
[Operation during execution of a BIDIN instruction]
Execution of BIDIN instruction Completion of reception by
BIDIN instruction
ON
OFF
OFF
Sequence
program
BIDIN
instruction
Completion device
Status display device
at completion
END
processing
END
processing
One scan
END
processing END
processing
Error
(1) In case of operation errors, the error flag (SM0) turns on and the error code is
stored in SD0.
See one of the following manuals according to the error code, and check and
correct the error.
<Error code>
4FFF
H
or less : QCPU User's Manual
(Hardware Design, Maintenance and Inspection)
Program example
The following example shows a program that receives any data using the bidirectional
protocol and stores that data in D10 or later.
The input/output signals of the Q series C24 are from X/Y00 to X/Y1F:
Clear the receive data count storage device to 0.
Designate the allowable receive data count.
•
Designate the receive channel.
•
With the normal completion, the receive data within
the allowable receive data count (user designated)
is read from the receive data storage area in the
buffer memory.
After the BIDIN instruction is executed, the user
designated read completion signal (M0) comes
on for 1 scan.
The reading of received data is performed by the
programmable controller CPU.