Hi Unobtanium,
Since this forum post is quite old, I would suggest creating a new post with the issue you are currently seeing as opposed to reviving this post. The following page should give you some help setting this parameter in LabVIEW:
http://zone.ni.com/reference/en-XX/help/371618K-01/lvmve/dsc_config_modbus_instance/
Thanks,
CH
Applications Engineering
National Instruments
http://www.ni.com/en-us/support.html