Event Attributes are additional pieces of data that can be associated with each event period generated by Flow. These additional pieces of data, when associated with event periods and overlaid onto time periods, provide context rich information that support decision making and provide insight.
Let’s add context to the “Filler 1 Run” Event you created earlier. Open the “Filler 1 Run” Event and expand the “Attributes” section. Undeploy your Event so that you can make configuration changes to it:
Right-click in the “Attributes” section and select “New”, “Attribute”. Name your new Attribute “Product”. Locate the “FL001.Product” tag in your Historian and drag it onto the “Product” Attribute.
Flow creates a new “Attribute Segment” name “FL001.Product” …
For the properties of this segment, change the “Enumeration” property to “Filler Product”.
An Event Attribute can be made up of one or more Segments concatenated together. The following Segment types are available:
- Retrieved – the value of the segment is retrieved from a Data Source. If the retrieved value is an integer, the segment can be linked to an Enumeration to map the integer values to string values.
- Constant – this is a constant string that can be added as part of an Attribute. This is useful for generating Attributes for Batch Numbers.
- Period Start – this segment uses the start date and time of the event period. Use the “Format” property to change the way you want the date and time to be displayed.
- Period End – this segment uses the end date and time of the event period. Use the “Format” property to change the way you want the date and time to be displayed.
- Period Index – this segment uses a unique Index that Flow assigns to each event period created (see section below).
Every event period created by Flow for an Event will generate a unique Index identifier. This Index auto-increments every event period. Expand the “Index” section of the “Filler 1 Run” Event …
There are a few properties that can be defined for an Event’s Index:
- Initial Value – this is the initial value that will be used the first time the Event is deployed (or, the first value that will be used of an Index “Reset”).
- Reset using – this specifies the Calendar to be used when applying a “Reset” rule to the Index. Leaving this blank will ensure the Index will never reset.
- Reset interval – this specifies how often the Index will reset using the above Calendar.
Use Attributes to generate additional Context
By making use of the Attribute Segments, you can actually generate information without the need to access your Historian. For example, your Historian does not provide any data relating to the Work Order being run by your Filler. Let’s create a “Work Order” Attribute for your “Filler 1 Run” event.
Create a new Attribute called “Work Order”, and add the following Segments to it:
- Constant “FL001”
- Period Start formatted to “yyyy” (i.e. only the year)
- Period Index formatted to “0000” (i.e. always 4 digits)
Deploy your “Filler 1 Run” event again, open the diagnostic grid on the Attributes and confirm the attribute values coming through for each event period:
Notice how the “Product” attribute has been mapped to a string value for the product. Notice how the “Work Order” attribute has been made up of:
“FL001” + Period Start (yyyy) + Period Index (0000) = “FL00120150141”