I’ve noticed that the gauge populated with “n/a” text. Is that a real state and is it accessible elsewhere in the platform? For example, could I force a gauge into a n/a state through a certain value placed into the attribute?
I see that occur when you have dashboard widget configured for a device property that isn’t defined against the device.
T
A great question - N/A on a gauge means that either the selected attribute is invalid for the selected device, or that we have no reported data for the attribute for the device for the selected time period. This is the equivalent to the notice “No Data To Display” that a lot of our other dashboard blocks show when there is no data. So it is not a “real” state, and not something you could deliberately get to display with a state report (well, unless it is a string attribute, and you actually reported the string N/A 
).
How about if you set the attribute to null?
If null is reported for an attribute, the data point will be ignored.
The Indicator Block does work similar to the Gauge Block, but does give you control over the specific text being displayed. You could use that to display N/A based on a specific attribute value of your choosing.
I’ve noticed that if you have a attribute defined for a dashboard gauge, and there has never been data against that attribute for a given device that it will correctly report “n/a” however it always says “a few seconds ago”. I think this is because I have my blocks set to show the “last data point” and there is none at all. However, other attributes that have had some history will say “3 days ago” for example if there has been null data in the past 3 days".
It makes sense on one level, but its a bit confusing sometimes since it suggests that something has happened “a few seconds ago”.