I just ran into something and I wondered if anyone else ran into this issue, which could just be a limitation of the PI WebServices currently? I have a PI tag that stores wind speed in m/s. In the PI AF I have two attributes for wind speed. One uses the default UOM of m/s, but the second one has UOM as km/s. When I view this attribute (km/h) in Processbook or PI Web Parts, I see the value in km/h. When I ask for the same data using PI Webservices, for the attribute, I get the values back in m/s. When I check the UOM property for the collection, it is in km/h. Has anyone else seen this, or is my system just nuts?
If anyone is interested, I am calling the PI WebServices from Silverlight, but that shouldn't make any difference.