Asynchronous Data

Due to the asynchronous nature of how DTM's battery-operated sensors purge their data to Dor's servers, foot traffic events are not available on a real-time basis as each sensor records events. Sensors attempt to check in with Dor servers on a fixed interval based on your account configuration. The default interval is 1 hour when foot traffic events need to be purged from a sensor. When no new foot traffic events have been generated, DTM sensors may move to a slower update interval to preserve battery life.

Occasionally, DTM sensors may be delayed in purging their foot traffic data when they have poor connectivity. During a loss of connectivity, DTM sensors continue recording foot traffic events and store them locally. When connectivity is restored the DTM sensor will purge these events to the server. During this time the API may not have the most up-to-date representation of foot traffic at any given location. The DTM API was designed with this asynchronous nature in mind as described below.

Data in the API can only be as up-to-date as the most recent check-in from each sensor. Sensors may check in with data recorded in the past (hours or possibly even days old). This makes simple implementations such as querying every hour for the previous hour's data problematic.