SLTA is not managed by the LonWorks Interfaces software. I think it is only controlled via the SLTA Link Manager software.
In the SLTA Link Manager software, look at Devices, Link Associations to see what LON number has been assigned to the SLTA-10. Then try running NodeUtil on that SLTA-10 to see if you can access it as a network interface:
NodeUtil -dLONx (where x is the number you see in the Link Manager).