Hello,
Look at the following link. Hopefully this will help.
http://exchange.ni.com/servlet/ProcessRequest?RHIVEID=101&RPAGEID=135&HOID=506500000008000000CDB00000&UCATEGORY_0=_49_%24_6_&UCATEGORY_S=0&USEARCHCONTEXT_QUESTION_0=-2147312566&USEARCHCONTEXT_QUESTION_S=0
JLV