Since you have the Serial RS-485 connection you will need to get some type of RS-485 board. The built in serial terminals that are in some computers use the RS-232 protocol. Here is a link to more information about NI Serial devices. From here just look at the RS-485 devices we have USB, PCI and PXI solutions. Also here's a KnowledgeBase that will give you a Serial Communication Starting Point. This should get you started there are also allot of other KnowledgeBases to find more information you can also go to ni.com and do a search for Serial and RS-485.
Regards Krista S. Applications Engineering National Instruments