Installation of an FDR

An FDR needs three things:


  1. A 110 Volt outlet both to power the device and as the subject of the frequency measurement.,
  2. A clear window view of the sky to receive GPS satellite timing information, and
  3. A broad-band internet connection for sending its measurements to the central server at Virginia Tech. University.


Assuming that your broadband access to the World Wide Web, is via DHCP (a plug and play method of getting an internet address) then installation is simply a matter of finding a good location and plugging everything in. In the case of a network involving fixed static IP addresses, then the FDR can be configured before it is sent to the end user.

A good location would be where an internet connection, a 110V wall outlet, and a window with an unobstructed view of the sky for GPS satellite communication are all together. Many university offices meet these requirements and hence a great many FDRs are installed in professor's offices. An unobstructed view would preferably be higher in the building overlooking an open space, not an opposing building across a narrow alley. Trees can also block the GPS signal. While the GPS is getting its geographic "fix" it will need to see 4 or more satellites at a time, but during operation a single satellite will be sufficient for the timing signal so sometimes a slightly obstructed view will suffice with a penalty of a longer wait to obtain a fix.

The window sill is the best location but actually fastening it to the window works as well. It may take extra time to "fix" from this non-standard orientation.


Once it is all plugged in, set up, and turned on you will need to wait through an initialization period until the GPS gets a "fix". The front display will then show the measured power frequency and voltage along with the Coordinated Universal Time (UTC) (also known as Greenwich Mean Time), and the number of GPS satellites currently locked. The green LED above the NET label should flash to indicate effective data transmission to the central FNET server.


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