When Data Cannot Be Exchanged In Polling Mode (Reading/Writing) - Mitsubishi Electric Melsec WS Series User Manual

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