FactoryTalk View SE - rslinx enterprise

Hello
I have a running configuration with

FactoryTalk View SE 8.0 connected with 2 compactlogix and 20 micro 850

i have a problem i think with rslinx enterprise cause i loose the connection
with some of the micro 850 but not all at the same time for example 1 every 2 hours. When i restart the service RslinxNG all the connections are ok again. but after some hours some stations are lost again. I don't know exactly what to do with this..

i also have a factorytalk view ME 7.0 application on this configuration with the same rslinx enterprise configuration and it works perfectly..

if someone can help ?
thanks

no idea ? ...
maybe if i can't find the problem a solution could be to detect when a communication is lost. and to restart it.
also i had the idea of create a batch file with net stop RslinxNG then net start RslinxNG
and run it every...hour..day

What about your data switch. Please tell us about your data switch and network connections.

Hello
the switches are Alcatel omniswitch 6500 (2) r 6212 (5)
this is a optical fiber ring. it is unique for the plant, i would say every computer or device from the plant is connected on it.
i have a specific subnet for my devices 192.168.88.xx but there is no VLAN to separate the ports of the switches. it is Schedule to have one in a near future but at the moment there is no.

from the Alcatel switches we have ethernet copper links to connect the different stations everywhere in the plant.
every utilization station is managed with a small micro 850 from AB which is communicating with Ethernet/IP with the FactoryTalk View SE local station.
I also have a Ethernet/IP link with a compactlogix CPU which is always ok
. What i loose is the connection with the micro 850's. please find attached the architecture in pdf file. If you need additionnal info..