REST api getPerformanceMonitorDetails

REST api getPerformanceMonitorDetails

Hi,
 
Using OpManage 11 build 11200.  I'm trying to use the REST api to get the value of a single performance monitor, but the getPerformanceMonitorDetails api doesn't appear to be available (it is documented in the OpManager REST API)  as OpManager responds with "The specified URL in incorrect."
 
Questions a) is this the correct API call to use to get the value of a single performance monitor, and b) if not, what should I use?
                New to ADManager Plus?

                  New to ADSelfService Plus?