Why does TS8 stop communicating

Windows 2008 R2
Digi TS8 version 82000684_V1
Using realport

The TS8 intermittently stops communicating. The only way to start it again is to reboot the TS8.
Can some please let us know what could cause this freezing up.

Also, is there any information anywhere on the system event log messages for DIGIRPS. What the events mean etc.