Module: powerNodeBase

Executive Summary

The powerNodeBase class is used generate a standard interface and list of features for modules that consume or provide power. Specifically, each PowerNodeBase:

1. Writes out a PowerNodeUsageMsgPayload describing its power consumption at each sim update

2. Can be switched on or off using an optional PowerNodeStatusMsgPayload

3. Can also be switched on or off using the public variable powerStatus

Core functionality is wrapped in the evaluatePowerModel() protected virtual void method, which is assumed to compute power usage based on a module specific mathematical model.

Protected methods prepended with custom are intended for module developers to override with additional, module-specific functionality.

For more information on how to set up and use classes derived from this module, see the simple power system example: scenarioPowerDemo.

Module Assumptions and Limitations

The power draw or supply for this module is assumed to be constant.

Message Connection Descriptions

The following table lists all the module input and output messages. The module msg variable name is set by the user from python. The msg type contains a link to the message structure definition, while the description provides information on what this message is used for.

Module I/O Messages

Msg Variable Name	Msg Type	Description
nodePowerOutMsg	PowerNodeUsageMsgPayload	Writes out the net power used/generated by a PowerNodeBase instance.
nodeStatusInMsg	DeviceStatusMsgPayload	(optional). If powerStatus is 0, the node is disabled; other values indicate various power modes depending on the module.

User Guide

• To specify the modules simulated power draw (neg. value) or generation (pos. value), set the variable nodePowerOut to the desired value in units of Watts.

• The module power status can be set using the public variable powerStatus. The default value is 1 meaning the device is on. If set to 0 the device is off and the power value returns to 0.

• The module power status can be set also through an optional input message. By connecting nodeStatusInMsg the status message is read in at every time step.

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class PowerNodeBase : public SysModel

#include <powerNodeBase.h>

power node base class

Public Functions

PowerNodeBase()

This method initializes the messaging parameters to either empty strings for message names or -1 for message IDs.

Returns

void

~PowerNodeBase()

Destructor.

Returns

void

void Reset(uint64_t CurrentSimNanos)

This method is used to reset the module. In general, no functionality must be reset.

Returns

void

void computePowerStatus(double currentTime)

Core compute operation that implements switching logic and computes module-wise power consumption.

void UpdateState(uint64_t CurrentSimNanos)

Provides logic for running the read / compute / write operation that is the module’s function.

Parameters

CurrentSimNanos – The current simulation time in nanoseconds

Public Members

Message<PowerNodeUsageMsgPayload> nodePowerOutMsg

output power message

ReadFunctor<DeviceStatusMsgPayload> nodeStatusInMsg

note status input message

double nodePowerOut

[W] Power provided (+) or consumed (-).

uint64_t powerStatus

Device power mode; by default, 0 is off and 1 is on. Additional modes can fill other slots.

BSKLogger bskLogger

BSK Logging

Protected Functions

void writeMessages(uint64_t CurrentClock)

This method writes out a message.

Returns

void

bool readMessages()

This method is used to read incoming power status messages.

Returns

void

virtual void evaluatePowerModel(PowerNodeUsageMsgPayload *powerUsageMsg) = 0

Virtual void method used to compute module-wise power usage/generation.

virtual void customReset(uint64_t CurrentClock)

Custom Reset method, similar to customSelfInit.

Custom Reset() method. This allows a child class to add additional functionality to the Reset() method

Returns

void

virtual void customWriteMessages(uint64_t CurrentClock)

custom Write method, similar to customSelfInit.

custom Write method, similar to customSelfInit.

Returns

void

virtual bool customReadMessages()

Custom read method, similar to customSelfInit; returns true by default.

Custom read method, similar to customSelfInit; returns true by default.

Returns

void

Protected Attributes

PowerNodeUsageMsgPayload nodePowerMsg

buffer of output message

DeviceStatusMsgPayload nodeStatusMsg

copy of input message

double currentPowerConsumption

class variable

double previousTime

Previous time used for integration.