Constantly torn communication with the modem.

Constantly torn communication with the modem.

I have a device NPort 5210, it operates remotely
Virtual COM-port computer opmanager. In the previous version opmanager it worked steadily in the new 11.6 connection constantly lost only restores service after restarting opmanager.
Where can I read the logs and how to determine the cause. What can you advise me.

                New to ADSelfService Plus?