I have Siemens now running my larger HVAC and lighting with 23 MBC's and lots of DPU's and TEC's . In the future I will have a central ice plant to cool 3 new 4-story buildings and eventually the entire college where i work. The people at the top want to use Lonworks for the central plant and some other control system that will interface with my current Siemens EMS. The powers that be say we are favoring one control system while spending public money. Has anyone encountered any major problems with Lonworks and interfacing two EMS control systems? I still have time to try and head this off and remain 100% Siemens if I can raise major objections to going with Lonworks.