Hey Cosec,
The following links apply to J1939 for CAN.
http://exchange.ni.com/servlet/ProcessRequest?RHIVEID=101&RNAME=ViewQuestion&HOID=506500000008000000DDAD0000&ECategory=Industrial+Networks.CAN
http://digital.ni.com/public.nsf/websearch/18DC960767E6D1D986256CA8007965C3?OpenDocument
Basically, J1939 is an application layer protocol that uses the CAN standard. National Instrument sells several different NI-CAN devices that you can use to communicate with J1939 devices using LabVIEW, CVI, or C.
http://sine.ni.com/apps/we/nioc.vp?cid=1329〈=US
I hope this helps out.
JoshuaP