Network Connection Problems - Omron CS1W-FLN22 Operation Manual

Troubleshooting Procedures

10-4-2 Network Connection Problems

Failed commu- Power supply
nications problems
Unstable or failed communications Does each node respond correctly to the
154
Is the main power supply indicator lit?
Is the power supply indicator lit on the
Communications Unit?
Is the HUB power supply indicator lit?
Ping command?
Is the collision indicator lit frequently?
Are there a maximum of four repeater lev-
els?
Is the distance between the hub and nodes
(cable length) within 100 m?
Are the hubs turned ON?
Is the correct communications cable con-
nected?
Is the communications cable connector
correctly attached?
Is the communications cable wired cor-
rectly (straight/crossed)?
Are the hub settings correct?
Are there too many cascade connections
from the switching hub?
Are Ethernet communications other than
FL-net being performed on the same net-
work?
Is the network load too high?
Section 10-4
Check the power supply, power cable con-
nection and voltage.
Check the power supply, power cable con-
nection and voltage.
Check the power supply, power cable con-
nection and voltage.
Check the power supply and cables of
nodes that fail to respond.
Check the contact between cables and
connectors.
Check the error with an analyzer.
Reconfigure the network using four repeat-
ers max.
Reconfigure the network with a distance
between the hub and nodes of 100 m max.
Check the hub power supply and power
cable connection.
Use the correct communications cable,
referring to 1-5 Specifications. For a baud
rate of 100 Mbps, the cable must be cate-
gory 5 or 5e.
Check that the communications cable con-
nector is securely attached.
Check the hub specifications and use the
correct wiring for the cable. Check the hub
settings.
Correct the settings if the hub uses
SCADA ports or individual settings for
each port. For details, refer to the hub's
operation manual.
Switching hubs are subject to transmission
delays. Therefore, the cycle time will be
affected if multiple switching hubs are con-
nected using cascade connections. Either
increase the minimum allowable frame
interval or reconfigure the network.
Communications will not be performed cor-
rectly if another network is combined with
the FL-net network. Make sure that only
FL-net communications are performed on
the FL-net network.
If a high network load (data link capacity,
number of nodes) is high, increase the
value of the minimum allowable frame
interval. The minimum allowable frame
interval can be changed using the CX-
FLnet or FL-net Unit Support Software.
After changing the setting, restart the FL-
net Unit or cycle the PLC power.