The MDR architecture incorporates Sensor to Manager communication and Manager to Manager communication.
A Sensor connected to an MDR pair maintains communication with both Managers at all times. The Primary Manager synchronizes data with the Secondary Manager every 15 minutes. However, the Primary and Secondary Managers receive system events from a Sensor independently, and store the events also independently. If the Sensor has trouble communicating with the Primary Manager, it will send a system event to the Secondary Manager about the communication error between it and the Primary Manager.