Mitsubishi Electric Melsec WS Series, User Manual

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MELSEC-WS
Troubleshooting
131
9.2 When data cannot be exchanged in polling mode
(reading/writing)
Troubleshooting
when data cannot be exchanged
in polling mode
*1,*2
Was the OPEN
instruction executed? (Was
M300 turned on?)
Is the Open complete
signal (M0) on?
YES
NO
YES
NO
Check if the QJ71E71-100
has sent a command
to the WS0-GETH.
YES
NO
Check the network totally including
the communication path between
the WS0-GETH and the QJ71E71-100,
a noise, and installation status.
NO
Is a response returned?
Check if the programs and network parameters
including a port number are correctly written
to the CPU module on the QJ71E71-100 side.
YES
Execute a PING test from the
QJ71E71-100 to the WS0-GETH.
Execute the OPEN instruction to open the connection.
(Turn on the open execution device (M300).)
Execute the BUFSND instruction and send the command.
(Turn on the send execution device (M400).)
Was the BUFSND
instruction executed? (Was
M400 turned on?)
YES
(M410 is on.)
NO
(M411 is on.)
Check the code of an error occurred by executing the
BUFSND instruction and eliminate the error.
(Eliminate the error, referring to the error code stored in D1.)
Check if the connection
has been opened.
YES
(M310 is on.)
NO
Check the code of an error occurred by executing the OPEN
instruction and eliminate the error.
(Eliminate the error, referring to the error code stored in D0.)
Was the
OPEN instruction
normally completed?
(Is M310 on?)
(The value was
added in C2.)
Was the
BUFSND instruction
normally completed?
(Is M410 on?)
(To the next page)
Figure 73:
Troubleshooting
flowchart when data
cannot be exchanged in
polling mode