HOW TO: manage event and list of devices in tables on Snap4City Dashboards

Snap4Event

In the IoT world, sensors and devices of various kinds share the data they detect with centralized units with the aim of analyzing and displaying the data. For example, pollution sensors scattered around the city can indicate on a map which areas are most polluted in real time.

Although the IOT world is perfectly suited to a case like the one reported above, the exception is made for events that may or may not have a temporal duration. In this scenario we evaluate the types of events to represent, then we move on to the representation of a unified model for their registration and finally we develop a graphical dashboard for viewing. Moreover, the events may be ONESHOT or REPEAT.

ONESHOT events are for example landslide, accidents, etc. They are Device Orinented, realted to the device, a set of devices are events

• They occur at a given time instant and may evolve chaiging the status in the successive time instants, and thus on messages posted on the IoT Device representing the Event.
• The evolution could be marked by some state: inception, stable, present, solved.
• Thus once the event is finished its visualization is completely part of the story and the event it not anymore active.
• In most cases, this kind of events are interesting only for the last message on the IoT Device representing the event. 
• in this case, one should ask which are the ACTIVE Event, menas to search in a category of Devices (according to the same device model used) and get those that have still non CLOSED status

REPEAT events are for exmaple: entertainment events on a theater, taxation registered on a speed measruing device of police, maintenance events of a certain machine or car, etc., They are message oriented, related to the messages of a unique Device.

• They have an initial description at the creation of the entity as an IoT Device in which the events occur.
• The single event is substantially an instance message of the IoT device of the entity.
• The temporal duration of the events is usually declared into the message variable, e.g., the datetime in which the show at the theter is going to be represented, the datetime in which the advertising can start and the final day of the representations. 
• In this casem on should ask to the list of messages of a certain device, for example occurred in a certain day, or period; or which have a certain date in a certain range of values 

Future / Past Events

Past-> Past events with respect to local time.

Future-> Future Events with respect to local time. for example for planning entertainment event, for project planning, etc.

Events with temporal Duration

Events with time duration are those events that have a Beginning, a Progress and an End. The duration of the event is assumed to be unknown, it will be the responsibility of the IoT devices to report the progression of the event and then indicate its opening, progress and termination.

An example could be road maintenance events, cataclysmic or dangerous events.

Events with no temporal duration (instant)

For Instant events we mean those events that do not have a temporal duration, this type of events can only be reported as having occurred at a given moment, they do not have a progression, nor a termination.

In the modeling these events will be represented as Events with Duration where the event start date and event end date coincide.

An example of these events can be Traffic Fines.

 

Possible Models

The idea is to identify the single model to which all types of events must refer, within it the model can in turn host the models that refer to particular cases, for example. seismic events, fines, maintenance work, etc.

Other features like device name, location etc. they are already specified in the structure of any IOTDevice.

General Model

Name	Description	Value for example
dateObserved	timestamp	timestamp
dateStart	Start event timestamp	Timestamp
dateStartShow	Strat promotion timestamp	Timestamp
dateEnd	End event timestamp	Timestamp, se non previsto = null
status	Event status	“Start” – Event start, “In Progress” – Event in progress, “End” – Event closed, “Future” – Future event
colorStatus	Icon color	Colors
iconID	Id of the icon	URL
shownStatus	Visualition Active/Not active	Active – Active for the visualization Inactive – Not active for the visualization
eventSeverity	Some coded status	integer
description	Description or event update	Text
eventType	Relatd/Not related from the device: ONESHOT or REPEAT	“DeviceUnrelated” – Not related to the device “DeviceRelated”- Related to the device
eventKind	Streent of the incident
uniqueEventIdentifier	Unique identifier of the event type REPEAT	Unique data of the device + progressive number assigned from the IOT device
Attributes: Address Cap Civic number Number of peole Relevance ….	Attributes	Specific attributes based on the event type (sismic, Attribuiti specifici in base al tipo di evento(seismic, fines, maintenance etc.)

Specific Models

As examples, here are represented some specific attributes.

 

Fines model for the AutoVelox (REPEAT)

Name	Description	Value for example
Plate	license plate	Alphanumeric
Speed	Speed	Numeric
SpeedLimit	Speed Limit	Numeric
UM	Unit of Measure	Alphanumeric

 

Maintenance Model (REPEAT)

Name	Description	Value for example
Company	Company in charge of the work	Alphanumeric
Type	Kind of work	Alphanumeric
Description	Description of work	Alphanumeric

 

Emergencies Model (ONESHOT)

Name	Description	Value for example
Category	Emergency category	Geophysical, Meteorological, Safety, Security, Fire Etc.
Emergency	Brief description of the emergency	Alphanumeric Es. building on fire
Description	Detailed description of the emergency	Alphanumeric
Urgency	Urgency of the emergency	Immediate, Expected, Future, Past
Severity	Emergency Severity	Extreme, Severe , Moderate, Minor, None
Certanty	Certainty about the emergency	Observed, Likely, Possible, Unlikely
PeopleAffected	Number of people involved in the emergency (Observed)	Numeric

 

Event Table User Manual

After downloading the node-red-contrib-snap4city-user updated package, to start using Event Table, use the Event Table node available in the S4CDashboard section of the Node-RED library column:

The following image shows an example with various configurations and can be downloaded here [ADD LINK]

Once the flow has been created and deployed in the chosen dashboard, following Widget is available on the dashboard:

To start viewing the data it is necessary to go in the node configuration, in this case in the function node before WidgetEvent:

Here we found::

• ordering: name of the column;prefix:
• devices URI prefix;
• devices: devices to which an event to be displayed is connected
• actions: actions available to be displayed in the actions column, by default the "pin" action is available and a pin icon is shown;
• columnsToShow: columns to be displayed in the widget, all non-chosen columns will be available via the drop-down menu

The “columnsToShow” and “ordering” fields must have columns available in the following list:

• device
• description
• severity
• startDate
• endDate
• dateObserved
• type
• colorStatus
• dateStartShow
• eventKind
• shownStatus
• status
• uniqueEventIdentifier
• latitude
• longitude
• specificData

Now, by clicking the inject node (timestamp) immediately the widget and the loaded events on the dashboard are loaded:

please note that the look and feel of the table would depend on the Style Chosen  the representation here are in editing 

By clicking on the + it will be possible to view the columns excluded from the view, this action is sent to node-red by default as "expanded" when it is opened and "closed" when it is closed:

please note that the look and feel of the table would depend on the Style Chosen  the representation here are in editing 

In the same way, by clicking on the sorting columns, the order change is notified:

By clicking on a certain action in the Actions column is possible to view the following data in the node-red debug area:

Where the following fields are shown:

• device: The selected device
• prefix: device URI prefix
• ordering: current ordering column
• action: Selected actions in the column “Actions”

If the loaded devices do not comply with the minimum requirements of the general model illustrated above, an error is reported on node-red where the missing values for each device are specified, as shown in the following image.

In this case we can see 3 devices that are not compliant with the requirements and with the respectively missing fields.