scope:

The messaging between Transportation Management Center and field devices is accomplished by using the NTCIP Application Layer services to convey requests to access or modify values stored in a given device; these values are referred to as objects. The purpose of this publication is to identify and define these objects definitions that may be supported by multiple device types (e.g. actuated signal controllers and variable message signs). The grouping of objects for a given device type is performed in the device-type-specific object definition standard.