How does HART support device identification beyond a simple tag?

• A. By using a vendor-specific command set only.
• B. Through unique identifiers such as UID or serial numbers and long/extended addressing options for polling individual devices.
• C. By requiring manual inventory from maintenance records.
• D. By using a separate wireless beacon for each device.

Answer: (B)

HART lets you identify devices beyond a simple human-readable tag by using each device’s own unique identifiers and by enabling targeting of a single device on the loop. Each device can store a UID or serial number that is globally unique, and the master can read these values to confirm exactly which device is present. In addition, extended (long) addressing lets the master poll a specific device by its unique identifier rather than relying on a shared short address or a tag that could be the same as another device’s. This combination—reading the device’s UID/serial and using long addressing to address one device at a time—gives precise, automatic identification and asset-tracking, which a mere tag can’t provide.

Other options don’t fit because a vendor-specific command set isn’t required for device identification in HART—the protocol uses standardized identification commands. Manual inventory isn’t automatic or real-time, and a separate wireless beacon for each device isn’t how HART communicates, since it operates over the existing two-wire loop with digital signaling on top of the 4-20 mA current.