Mitsubishi Electric Melsec Q Series User Manual page 217

6 DEDICATED INSTRUCTIONS
[Operation of the local station when the SREAD instruction is being executed]
Sequence program
SREAD instruction
Send/receive
direction flag
Completion device
Status display device
at completion
[Operation of the other station when the SREAD instruction is being executed]
Sequence program
OFF
Completion device
Errors
Program example
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END END
processing processing
ON
OFF
ON
OFF
OFF
OFF
END END
processing processing
(5) When the instruction is executed using J.SREAD/G.SREAD, the next read
processing is executed in succession after one read processing is completed
while the read command is on.
When the instruction is executed using JP.SREAD/GP.SREAD, the read
processing is executed only once when the read command switches from off to on
(at rise).
(1) When a dedicated instruction ends with an error, the abnormal completion signal
(D2) + 1 turns on and the error code is stored in the completion status (S1) + 1.
See the following manuals regarding the error code, check the errors and take
corrective actions.
<Error codes>
4FFF or less : User's Manual (Hardware Design, Maintenance and Inspection)
H
C000 or higher: User's Manual (Basic)
H
See the program example of the READ instruction described in Section 6.4.
The SREAD instruction only differs from the READ instruction on one point,
namely that the read notification device (D3) is designated at the end of
arguments.
SREAD instruction execution
is completed
Completion of send of
device data designated with
the SREAD instruction.
for the CPU module used
MELSEC-Q/L
END END
processing processing
ON
Abnormal
ON
completion
Normal
completion
One scan
END END
processing processing
ON
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