Troubleshooting by Symptom
The troubleshooting measures for each symptom during CC-Link IE Field Network Basic are shown below. If an error has
occurred in the FX5-ENET, identify the error cause using the GX Works3. (Page 43 Checking the Module Status)
When the diagnostics function does not start
If the CC-Link IE Field Network Basic diagnostics does not start, check the following.
Is the master station power ON?
When the transmission status is disconnected or unfixed
If the CC-Link IE Field Network Basic diagnostics transmission state is disconnected or not established, check the following.
Are the IP address and subnet mask of the master station/slave stations
Is the IP address already in use?
Is there any device having the same IP address as the master station/slave
stations within the same network address?
Is the same network address set to the master station and slave stations?
Is the access blocked?
Is any access from slave stations blocked in "IP Filter Settings" of the master
Before an error was detected, has any device on the line, such as the master
station, slave station, or hub, been replaced with a device having the same IP
address as that of the device before replacement?
*1 There may be cases when duplicated master stations or duplicated slave stations are not detected as an error.
*2 Devices on Ethernet have a table of IP addresses and their corresponding MAC address, called the ARP cache. When a device on the
line is replaced with a device having the same IP address, the MAC address in the ARP cache becomes different from that of the
replaced device. This may cause incorrect data communications. The ARP cache is updated by resetting a device or after a certain time
has elapsed. The time varies depending on the device.
■CC-Link IE Field Network Basic
Are the devices specified in the refresh settings for the master station correct?
Are the devices specified in the refresh settings for the master station used in
Turn ON the power for the CPU module connected to the master station.
Check and correct the IP address and subnet mask of the master station/slave
Set a unique IP address to the master station/slave stations.
• Check and correct the IP address and subnet mask so that the network
addresses of the master station and slave stations match.
• Check and correct the subnet mask of the master station and slave stations
so that they match as normal values.
Check the security settings such as a firewall.
Allow the access from the IP address of the corresponding slave station.
If a device (master station, slave station, hub, etc.) on the line was replaced
with a new device having the same IP address, take one of the following
• Wait until the ARP cache is updated. (The waiting time varies depending on
• Restart all devices on the line.
Check and correct the refresh settings.
Check the settings and programs for the master station/slave stations, and
correct them if they are incorrect.
9.5 Troubleshooting by Symptom