Communication Cannot Be Performed Occasionally When Executing User Program; Station Is Disconnected; Communication Is Unstable - Mitsubishi Electric MELSEC SW1DNC-CCIEF-B User Manual

Communication cannot be performed occasionally when
executing user program
When the communication cannot be performed occasionally when executing a user program, check the following items.
Item
Is the error code returned to the user program?
Can the network error be monitored with utility?
Does the same error occur when adding the station to the
system?
If the problem is not solved by the above corrective actions, refer to the following section and contact us.
Page 166 Information Required for Inquiries

Station is disconnected

The following explains the troubleshooting when the following symptoms have occurred and the station is disconnected.
• The connected station is disconnected unexpectedly.
• Data cannot be read from/written to the accessed station.
• Communication with the accessed station occasionally fails.
• A relevant station repeats network connection and disconnection
When the station is disconnected, check the following items.
Item
Is there influence of ambient temperature or noise?
Is there an error in the cable or hub?
Is the wiring proper?
If the problem is not solved by the above corrective actions, refer to the following section and contact us.
Page 166 Information Required for Inquiries

Communication is unstable

When the link scan time and transmission delay time is abnormally longer or a timeout occurs during transient transmission,
check the following items.
Item
Is there influence of ambient temperature or noise?
Is the L ERR. LED of the master or slave station ON?
Does the error occur on the "Selected Station Communication
Status Monitor" screen in CC-Link IE Field Network diagnostics?
If the problem is not solved by the above corrective actions, refer to the following section and contact us.
Page 166 Information Required for Inquiries
Corrective action
Check the returned value of the communication function. (Page 167 Error Code List)
Check the network status with the utility. (Page 164 Checking network status with CC-
Link IE Field Network diagnostics)
Check if the same error occurs when adding the station in order next to the existing station
for the system configuration which is configured only by a master station and own station. If
the same error has occurred, check the added station.
• Page 157 Checking installation environment
• Page 157 Checking cables and wiring
• Page 161 Board test
Corrective action
Check the installation environment. (Page 157 Checking installation environment)
Check the cables and wiring. (Page 157 Checking cables and wiring)
Corrective action
Check the installation environment. (Page 157 Checking installation environment)
Check the LED and take corrective action in the case of L ERR. LED turned ON. (Page
163 L ERR. LED/L ER LED is turned ON)
When an error occurred on PORT1 and PORT2 , perform cable and self loopback tests.
(Page 55 Cable test, Page 49 Self-loopback test)
16 TROUBLESHOOTING
16.5 Troubleshooting for Data Link
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