In HART, what does a burst data frame carry?

• A. Firmware updates only
• B. Periodic device data such as secondary variable values or diagnostics when in burst mode
• C. Alarm history
• D. User access credentials

Answer: (B)

In burst mode the HART device sends a rapid stream of data frames that deliver live, periodic information without needing constant polling. The burst data frame is specifically used to carry periodic device data such as secondary variable values and diagnostic information. This lets the host receive current measurements and health/status data efficiently. Firmware updates aren’t part of burst frames, as updates follow separate procedures. Alarm history isn’t provided through burst frames, since burst data focuses on ongoing measurements and diagnostics rather than stored events. User access credentials aren’t transmitted in burst frames either, since security-related information is handled outside of burst data for safety.