Keith,
It depends on what kind of the program is written in the MNL-200 and V2 to have acces to the controller there is no plug-in you need Workplacetech for siebe\Invensys\TA. Some engineers are programming these controllers with a limted number of connected snvt. If you don't workplacetech it will be in the future difficult to replace devices. The only solution in that case is using an other manufacturer who has AX plug-ins for his lon VAV controllers ( Distech or Honeywell). In the current situatie these contrllers are comminisoned with a LNS tool so if you have the database you can see which bindings there are and snvt. you can try with a lns browser to write a value to that snvt like minflow and see what is happening.
succes
Frank