L Connection Network Building Automation System Miscellaneous - Other Transformer - 24V, Plug-in Communicate with Prodigy Control System on Lennox Premium Rooftop Units, non-Prodigy Control Lennox or aftermarket equipment with optional Network Thermostat Controller, and other building functions with the Building Controller. Controls a wide range of HVAC and building operations - such as heating and cooling, lights, signs and exhaust fans - from a single point of contact Supports constant volume bypass and true variable air volume zoning applications with factory variable-frequency drives Compatible with Lennox rooftop units and split systems, as well as electromechanically controlled third-party equipment