Communications

The Communications Applications Concepts is located at V3_applications_concepts.

=Communications Module=

The communication module will be based upon a simple performance model. Essentially, it will perform as a dispatching “black box”. Messages or commands are created by external objects, delivered into the network model via a network interface device, network delays are applied, and the message is delivered to the appropriate object via another network interface device. The “black box” will initially consist of a number of simplified network properties to demonstrate the anticipated delay times found within the network.

The following will be broken into three sections, each dealing with different aspects that will need to be addressed to develop the communications module. First, descriptions and requirements of the “black box” network will be provided. Second, parameters and behaviors of the network interface devices will be described. Finally, the general modifications required to existing objects for usage of the communication module will be described.

Network Object
The network object will collect all of the applicable signals desired by the overlaying system and then determine the amount of time necessary to deliver the signal to the appropriate object. Actual collection and delivery of the messages will be handled by the network interface device, and will be further described in a later section. As an initial model, the network module will only be concerned with a few parameters; these will include average network latency, bandwidth limitations, and queuing of messages during high levels of congestion. In addition to accepting and delivering messages, the network object will need to communicate to the network interface device any cases where the message was not accepted by the network due to limitations. All of the routing information contained within a standard network will not be explicitly modeled.

Network Object Inputs
Table 1: Network inputs.

Network Interface Device
The network interface device will be required to bridge the communications module with any other existing module. This is analogous to triplex meters in power flow being used to attach residential models to the power system; however, due to the constraints of the parent-child relationships, the order will need to be reversed. The network interface device will become the child of the object is controlling. Similar to when using the meter object, any object that interfaces with the network module will need additional logic to detect if a communication device is present. Additionally, each object that interfaces with the device will need logic designed specifically for handling the control signals that will be now sent across the communication module as opposed to directly. For example, the volt var control object will need to deliver the modified set points to the network interface device as opposed to directly to the regulator object. For communication to occur between two objects, both will be required to be attached to a network interface device.

The network interface device will either deliver messages from the object to the network or from the network to the object. It will also handle any processing delays that may be required, or when the network is in reject mode, it will be required to store and resubmit data as necessary.

Network Interface Device Inputs
Table 2: Network Interface Device inputs.

How information will be passed
Messages will be passed within the communication module as a structure. Minimally, this will contain the source, destination, size, bandwidth, delay, and data, and may be expanded later to include other information. bandwidth will be assigned by the network object and delay will define the amount of latency determined by the network object.