Troubleshooting USB Communications
You may occasionally experience difficulty communicating with a vbSeries portable instrument when using a USB connection and version of Ascent and instrument firmware released prior to 2009. This usually indicates a communications conflict or firewall activation. We recommend upgrading to the latest release of Ascent, which includes a ‘Plug and Play' USB driver that will prevent these issues. If this is not possible, the steps below may resolve the conflict
- Connect the powered instrument to the PC using the supplied USB cable.
- In the Ascent software, select Edit>Manage>vbInstruments... The Manager - VB Unit window will open.
- Double-click your instrument (identifiable by its serial number) in the new window. The instrument properties window will open.
Note: if your vbSeries instrument is not listed, it has not yet been added to the Ascent software's instrument database.
- Check the instrument's IP address in the IP address: field.
- On the vbSeries instrument press
Options, then 
Network. Check that the IP listed beside the 
USB button matches the IP in the Ascent software. If the IP addresses do not match, change the address in the software Properties window to match the instrument IP, then restart the instrument (press and hold
then press
). Close the Properties window and attempt to connect to the instrument once again. - If you are still unable to communicate with your instrument, temporarily disable any firewalls and check whether doing so resolves the problem. If communication is restored, add a firewall exception for the Ascent application 'masvb32.exe' (in the Program Files\Commtest\Ascent folder on your PC) or open port 13000.
Last Reviewed: 08/Jun/2009 Source: Ascent Software Guide Revision 15 April 2009 - page 358 & 359