Hello,
UseDataTemplate property from series has to be set to ‘true’ if you want to create your own data point template. If you want to use default appearance of data points set UseDataTemplate to ‘false’.
Please use this document which shows how to create a data point template:
http://help.infragistics.com/Help/NetAdvantage/WPF/2007.2/CLR3.X/html/xamChart_Using_a_DataTemplate_to_Style_DataPoints.html
Thanks,GoranS