The N2 bus and N2 devices were developed long before the definition of the BACnet protocol and the concept of a Priority Array. Therefore, each N2 command is executed as soon as it is presented to the N2 bus and is recognized by the target device. N2 devices have four basic commands that they support: N2 Read, N2 Write, N2 Override, and N2 Release.
However, BACnet expects devices to honor the Priority Array concept so the BACnet-N2 Router acts as a proxy for the N2 devices and emulates a Priority Array for them. From the standpoint of a BACnet client or device wanting to talk to a N2 device via the S4 Open: BACnet-N2 Router it can utilize all features of a BACnet Priority Array.