Yes, you do have to use the flexmotion functions in order to access the analog input on the FW-7344.
See this post for more explanation:
http://exchange.ni.com/servlet/ProcessRequest?RHIVEID=101&RPAGEID=135&HOID=5065000000080000001D6D0000&UCATEGORY_0=_14_&UCATEGORY_S=0
-Julie