Hello,
If your device has a regular RS 232 port, you can use Visa to communicate with your device (open, read, write,...)The VIs are in LV in the Block Diagramm under Functions>>InstrumentI/O>>Visa. I am not sure if you need to make any special configuration but you should be able to use "Visa Open" or "Visa configure Serial Port" to open a Sessin to a COM port (ASRL1 = COM1, ASRL2 = COM2) then use "Visa Write" or "Visa Read" to communicate with your device. Dont forget to use "Visa Close" to end your Session.