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Sample Ladder Programs Section 4-5
4-5-3 Sample Ladder Program Processing Flow
The following flowchart shows the flow of processes in the sample ladder pro-
grams.
END
Initial processing
# Executed automatically.
Connection open processing
Connection open
successful?
Abnormal completion signal
M101 turns ON and the error code
is stored in the completion
status area (D101).
Abnormal completion signal
M301 turns ON and the error
code is stored in the completion
status area (D3001).
Abnormal completion signal
M501 turns ON and the error
code is stored in the completion
status area (D5001).
Abnormal completion signal
M201 turns ON and the error
code is stored in the completion
status area (D2001).
Monitor message creation
BUFSND instruction execution
Message
communication
successful?
Request message
communications
processing
Status
monitor
processing
Connection
open
processing
Response
message transmission
processing
Connection
close
processing
BUFRCV instruction execution
Message
reception
successful?
Connection close processing
Connection close
successful?
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