With a utility network, you can model features to a high degree of realism with terminals on devices and junction objects. Features in the field have defined locations or ports from which resources, such as electricity and water, flow in and out. A utility network allows you to optionally model these ports with terminals.
For example, an electric distribution transformer (shown above) has five ports, two on the high side named H1 and H2 and three on the low side named x1, x2, and x3. You can model this transformer in one of two ways: with a simple two-terminal configuration or a detailed five-terminal configuration. The five-terminal configuration corresponds more closely to the ports on the physical transformer and is preferable if you want to achieve a high-fidelity representation.
To learn more about terminals, see Terminal management.
Connection points with terminals
A key use of terminals is to define the origin of a subnetwork. For example, in an electrical system, a subnetwork typically begins at the load side of a breaker in a substation. Some external analysis software, such as electric voltage drop analysis, relies on a complete definition of devices that includes terminal definitions.
Not all features require the definition of terminals. If a feature has two terminals that are equal and interchangeable, such as the two sides of a switch or valve, you do not need to define terminals.
The situations where you should define terminals are as follows:
- Features that will serve as a subnetwork controller
- Features with three or more physical ports that you need to model
- Features with two ports that are distinctly different, such as a high-side and low-side port on a transformer device
- Features with connection points that only allow flow in one direction, such as check valves in a water system or network protectors in an electric system
Terminals are not features and do not appear on the map. They exist as logical connection locations on a device or junction object that allow you to control how other features can connect, and the valid paths through which a network commodity can travel. Certain network rule types can be defined at the terminal level.
When you connect features with terminals to the endpoints of lines, edge objects, junctions, and other devices or junction objects (with or without terminals), you specify which terminal connects which feature.
For example, in an electric system, you connect the high-side terminal of a distribution transformer to a line with medium voltage, and the low-side terminal to a line with low voltage. This behavior is enforced using network rules.
Terminals are configured on a feature by assigning a terminal configuration. A terminal configuration is added to a utility network and assigned to specific asset groups and asset types in the Device feature class or JunctionObject table.
A terminal configuration has a directionality setting that dictates which way a resource flows through it. It has a set number of terminals, each with a name. Terminal configurations with three or more terminals have valid paths defined to constrain how the resources flow through the paths between pairs of terminals. To learn more, see Terminal management.