ML 1100 connected to three other PLCs

Hi,

I have an issue with ML1100.This PLC is connected to three more plc,one control logix and two compact logix.These PLCs are connected through ethernet with a unmanaged ethernet switch (normal 5 port hub).I have used messaging from both control logix and compact logix to transfer some data to ML 1100.This ML1100 is is configured as modbus slave.Now my problem is that ML 1100 getting freezed on its ethernet port.(data becoming steady).But in control logix and compact logix message instructions showing no errors.Any body please advice me how we can resolve this issue.Is it because of normal ethernet hub instead of a managed switch.

It is an unmanaged ethernet SWITCH or a HUB? There is a difference. If it's a Hub then I could possibly see that causing problems. For that application though I would think a single unmanaged switch would be fine, especially if it's all just standalone with maybe an uplink. If you currently have a hub, I would try a switch. They're not very expensive.

I had a similar issue with a Compact Logix that would constantly lose ethernet comms like you described. It would take a power cycle to get it "unstuck." Putting all the PLCs on their own subnet with managed switches solved that problem.

The three existing PLC using N tron unmanaged switch.So do I need to use a managed switch now.What is the advantages of using a managed ethernet switch with unmanaged switches.