DIGI ONE on a VM Connectivity problems


we are using DIGI ONE SP to connect a GSM modem to a Windows Server 2008 R2 virtual machine on Vmware ESX DRS Cluster.

The modem itself works fine, however the Event viewer display occasional timeouts with this error message:

Serial Port COM3 could not be opened for svchost.exe. The device either lost its network connection to the device or the local driver is being disabled.

The modem generally will recover from this error and function. However there were instances where the modem did not recover.

Digione itself is configured as RealPort. I configured “optimizate for latency”.

Could you recommend any troubleshooting procedures that I could try?

I am guessing for some reason the COM3/realport is being ‘cycled’ by the app, so closed and reopened too rapidly. Thus the ‘old’ COM3 has not yet closed by the time the ‘new’ COM3 is attempted to open. So to close the port, the DOSP has to agree, which may take longer than your tool is waiting.

If you go into the ‘device manager’ (if they have one in Win Srver), you’ll find a ‘multi-port device’ which has various internal RealPort settings. I can’t offer any specific setting, but you’ll find some in here to disable some of the ‘round-trip’ hand-shaking used to open/write the port. For example, I THINK (if memory serves me) you can make ‘writes’ always succeed, which means if the DOSP is slow to respond your app will gloss of this it as a serial corruption error & not a serious port failure, etc.