Mitsubishi Electric MELSEC iQ-R Series User Manual page 198

Communications are unstable
When cyclic data transfer processing time or transmission delay time is long or when a transient transmission timeout
occurred, check the following items.
Check item
Is the L ER LED of the RJ71GN11-T2 turned on?
Is the ambient temperature for the module outside the specified range?
Is any error shown in "Selected Station Communications Status Monitor"
of CC-Link IE TSN/CC-Link IE Field diagnostics?
Is there any noise affecting the system?
If the above actions do not solve the problem, perform the following test to check for an error.
• Module communication test ( Page 168 Module Communication Test)
SLMP communications failed
When communications using the SLMP cannot be performed, check the following items.
Check item
Has the connection with the external device been opened?
Is the correct command format used for the command type, device
specification, address specification, and others?
Did the external device send a command?
Was a response returned to the device that had sent the command?
Is the same communication speed set for the connected device and
access destination?
In multicast mode, is a standard Ethernet device connected to a local
station or remote station that does not support the multicast filter?
In multicast mode, are a local station and an Ethernet device connected
on the end side via a switching hub?
If the above actions do not solve the problem, perform the module communication test to check for hardware failure. (
Page 168 Module Communication Test)
*1 If the connection of only the external device is closed due to communication cable disconnection, personal computer restart, or other
reasons, reopen the connection using the same port used before the error occurred. A connection is not closed if another Active open
request is received from the external device with a different IP address or a port number.
■If the RJ71GN11-T2 with a firmware version of "13" or earlier is used
If the RJ71GN11-T2 with a firmware version of "13" or earlier is used, also check the following items.
Check item
In multicast mode, is a standard Ethernet device connected to the
master station?
4 TROUBLESHOOTING
196
4.4 Troubleshooting by Symptom
Action
If turned on, perform troubleshooting for a case when the L ER LED is turned on.
( Page 165 When the L ER LED turns on)
Keep the ambient temperature within the specified range by taking action such as
removing heat source.
If an error is identified at P1 or P2, perform a module communication test.
Change the placement and/or wiring of the modules so that the system is not
affected by noise.
Action
• If the connection with the external device is not opened, perform the open
*1
processing.
• If an error occurs, check and eliminate the error cause.
Correct the command format. ( SLMP Reference Manual)
If the external device did not send a command, send a command to the RJ71GN11-
T2.
• If no response was returned, check if the correct IP address was specified in the
command. If not, correct the IP address and send the command again.
• If a response was returned, check the end and error codes to correct the faulty
area.
Change the connection destination so that the connected device and access
destination have the same communication speed.
• Connect the standard Ethernet device to a local station or remote station that
supports the multicast filter.
• Set unicast mode.
• Take actions so that the Ethernet device does not receive cyclic data in multicast
mode.
• Configure settings with the switching hub so that the multicast frame (with
multicast MAC address 09:00:70:00:10:02 and 09:00:70:00:10:05) will not be
transferred to the port of the standard Ethernet device.
• Check the connected device and do not connect both a local station and an
Ethernet device on the end side of the switching hub.
• Set unicast mode.
• Take actions so that the Ethernet device does not receive cyclic data in multicast
mode.
Action
• Connect the standard Ethernet device to a local station or remote station that
supports the multicast filter.
• Set unicast mode.
• Take actions so that the Ethernet device does not receive cyclic data in multicast
mode.