Subnetwork controllers

A subnetwork controller defines the origin of a subnetwork. The type of subnetwork controller defines how a resource flows through a network. Once a feature is set as a subnetwork controller, its asset group and asset type cannot be changed.

Define what features can be subnetwork controllers

The subnetwork controller network category is a system-provided network category that can be assigned to asset types from the Device feature class and JunctionObject table. This is required to allow terminals on the features to be set as subnetwork controllers. Subnetwork controllers are used in subnetwork management to define the origin of a subnetwork.

This network category is set on a device or junction object at the asset group and asset type levels by the utility network administrator at the time of configuration using the Set Network Category tool.

Types of subnetwork controllers

There are two types of subnetwork controllers: sources and sinks. The subnetwork controller type determines how the network resource flows through all subnetworks in a domain network.

If the domain network is defined with the source subnetwork controller type, a resource can only flow away from or exit subnetwork controllers; the resource cannot travel toward or into them.

Source-based subnetwork

If the domain network is defined with a sink subnetwork controller type, a resource can only flow toward and enter subnetwork controllers; the resource cannot travel away from or exit them.

Sink-based subnetwork

Dive-in:

For partitioned domain networks, the Modify Subnetwork Controllers pane filters the terminals drop-down menu when setting a subnetwork controller based on the subnetwork controller type:

  • Source-based domain networks— Only downstream terminals are listed in the terminals drop-down menu for features with a directional terminal configuration.
  • Sink-based domain networks— Only upstream terminals are listed in the terminals drop-down menu for features with a directional terminal configuration.

Create a subnetwork controller

Subnetwork controllers are set at the terminal level on features from the Device feature class and JunctionObject table. A single device or junction object can have multiple terminals that are defined as subnetwork controllers. Subnetwork controllers define the origin of a subnetwork and the flow direction a resource can travel in a subnetwork.

The following administrative configurations must be set for a subnetwork controller to be defined:

  • A directional terminal configuration with upstream and downstream terminals must be created and assigned to the desired asset type if it belongs to a partitioned network.
  • Subnetwork controller network category—Specify which asset types are valid subnetwork controllers, for example, circuit breakers and power transformers.
  • Domain network—Define the subnetwork controller type allowed for subnetworks in a domain network: source or sink.
  • Tier group—A tier group must be defined for hierarchical domain networks.
  • Tier—A tier must be defined for the subnetwork to participate in.
  • Subnetwork definition—Specify the device or junction object asset allowed to be set as a subnetwork controller for subnetworks in a tier.

Once the administrative configurations have been set, terminals on individual features are set as subnetwork controllers. For a terminal to be set as a subnetwork controller, the following must be true:

  • The feature to which the terminal belongs must be from the Device class or JunctionObject table.
  • The feature must be deemed a valid asset type; the feature has an asset type that can be set as a subnetwork controller (network category) and can participate in the desired tier (subnetwork definition).

Once these requirements are met, a subnetwork controller can be set using the Modify Subnetwork Controller pane. Aside from manually setting subnetwork controllers, you can import them using the Import Subnetwork Controllers tool. All prerequisites and restrictions previously mentioned apply to importing subnetwork controllers.

Assign a subnetwork controller

When a terminal is set on a feature as a subnetwork controller, a unique name for the controller in the tier must be provided. The name of the subnetwork controller is stored in the Subnetwork Controller Name attribute on devices or junction objects with one or more subnetwork controllers. This Subnetwork Controller Name attribute is also stored in the Subnetworks table and the SubnetLine feature class. The Subnetwork Controller Type parameter is set during the creation of the domain network and can be found on the utility network's Layer Properties dialog box in the General section for each domain network on the Network Properties tab. To learn more, see Subnetwork name.

Only upstream and downstream terminals can be set as subnetwork controllers if the network is partitioned. In a partitioned network, upstream and downstream terminals allow flow direction within a feature to be determined on the fly during tracing events. Flow direction for an entire subnetwork is determined by the type of subnetwork controller. Upstream terminals act as subnetwork sinks; a resource can only flow toward this type of terminal, not away from it. Downstream terminals act as subnetwork sources; a resource can only flow away from this type of terminal, not toward it.

Both radial and mesh subnetworks support multiple subnetwork controllers. If a trace detects subnetwork controllers with different subnetwork names, an error is returned. This is true for all types of traces except connected traces. The error that is returned indicates that there are two or more subnetworks that are traversable (as specified in the subnetwork's trace configuration). To learn how subnetwork controllers behave in upstream and downstream traces, see Utility network trace types.

After a device or junction object has been assigned as a subnetwork controller, the feature cannot be deleted, and the asset type and asset group attribute fields are read-only. Subnetwork controllers are assigned at the terminal level, so it is important to ensure that the assigned terminal configuration is not modified. For example, do not remove terminals or change the valid paths of a terminal configuration that has been assigned to an asset type that has the subnetwork controller network category assigned to it. Create a terminal configuration specifically for your controller features.

To make changes to the asset group and asset type attributes or to the assigned terminal configuration, you must first remove the subnetwork controller by using the Modify Subnetwork Controller pane. To learn more, see Remove a subnetwork controller.