Chapter 4: DataStore DataStore items are data points at the Fleet Manager and each AMR that can be evaluated for status and other monitoring purposes. They are specific to the Fleet Manager and each AMR. Each DataStore item describes the data point, i.e. data type, its name, source, etc. Some examples of DataStore items are: l Cumulative number of jobs an AMR has completed l The distance driven by an AMR l An AMR's current location l An AMR's current battery state l Information about the SetNetGo software version At startup, the Integration Toolkit generates or updates its list of available DataStore items (a common list is kept for all AMRs).
To see a complete list of all DataStoreItem items that are available on your system, issue a REST call or review the data_store_item_view view. Refer to DataStore on page 23 and SQL with PostgreSQL on page 12 for more information. Values for these DataStore items are made available from the Integration Toolkit through a subscription model (available through all three channels) or with the DataStoreValueLatest REST command, which ignores subscription state and obtains the latest value from the entity in question.
With the subscription model, a user specifies a subscription interval for a DataStore item and the Integration Toolkit will obtain DataStore values from the target entity at the subscription interval specified, and provide access to it via all communication channels. Both SQL and REST will return the most current DataStore values from the last subscription period. Streaming interfaces will return entries every time a DataStore value changes. If there are no changes to the value of a DataStore item, the value will not be updated. IMPORTANT:
Care should be taken to avoid high frequency subscription rates that are less than 1 second to prevent over-subscription on large numbers of data entities. Though testing has been done at higher levels, subscription rates producing 200 or more updated values per second should be avoided. 4.1 Common DataStore Use Cases Common use cases when working with the DataStore are provided below. Manually Obtain a List of Possible DataStore Items This use case is typically executed during the initial programming phase to learn about what data can be obtained from the system.
A programmer should query the data_store_item_view to get the most current list of DataStore items and details that can be accessed during the auto- mated run time. This information can also be obtained with a REST call (/DataStoreItem) but the SQL query method provides an easier way for a programmer to view this information. 20964-000 Rev. C Fleet Operation Workspace Core Integration Toolkit 23 User's Manual