MITSUBISHI ELECTRIC QJ71C24N - Manual (Page 245)

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MELSEC-Q
9 DEDICATED INSTRUCTIONS
1 When setting "Word/byte units designation" by GX Configurator-SC, set the
number of bytes when bytes are designated and set the number of words when
words are designated as the unit types.
2 The settings are done by either of the following:
• User: Data set by the user before executing the BIDIN instructions.
• System: The PLC CPU stores the execution result of the BIDIN instructions.
Function
(1) The function stores in the device designated in (D1) and succeeding devices the data
received via the bidirectional protocol of the module designated in Un, according to
the control data of the device designated in (S) and succeeding devices.
(2) When a BIDIN instruction is executed on a channel, other BIDIN instructions
cannot be executed on the channel at the same time.
If an attempt is made during execution of a BIDIN instruction to execute another
BIDIN instruction, the second instruction will not be executed until the execution of
the first instruction is completed.
(3) It cannot be used along with BUFRCVS instruction (for interrupt programs).
(4) 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