The PDW-700 cameras are balanced for daylight optically and then corrected electronically for tungsten etc.
Traditionally cameras were balanced for Tungsten and then added colour correction optical filters to get to daylight. This was done as CC filters absorb light and thus make the camera less sensitive. Normally when shooting outdoors in daylight sensitivity is not an issue while shooting indoors under tungsten light you used to need every bit of sensitivity you could get.
The down side to this approach is that tungsten contains very little blue light so to get a natural picture the blue channel was often running at quite a high level of gain which increases noise in the blue channel and thus overall noise. In addition when you rotated in the CC filters to get to daylight the sensitivity of the camera was reduced, so you did not have constant gain.
With the PDW-700 (and also the F350 I believe) the cameras are essentially balanced for daylight, without the use of any CC filters, which helps reduce noise in the blue channel. Then for tungsten shooting you electronically re balance the camera. By doing this the overall sensitivity of the camera is constant whether shooting at 3.2K or 5.6K and you only get additional blue channel noise while shooting under tungsten. If you are worried by blue channel noise you can always correct from daylight down to tungsten with an optical CC filter (80A) and leave the camera set to daylight, although this will reduce the systems overall sensitivity by around 1 and a half stops.