Advanced HART Protocol Quiz: 25 MCQs with Detailed Explanations

In Burst Mode, a HART device sends the same data repeatedly, which is useful for monitoring real-time values without the master constantly requesting it.

In multi-drop mode, devices use digital communication only, so the analog current is fixed at 4 mA to maintain a consistent baseline without transmitting additional analog information.

Universal Commands, such as command #1 (“Read Primary Variable”), are essential for retrieving process variables, making them accessible across all HART devices.

The Device Status byte in HART messages reports errors, such as sensor faults or configuration issues, and provides general health information about the device.

HART supports multiple dynamic variables (PV, SV, TV, and QV) and uses extended device status to provide detailed information from a single device.

This command sets the polling address, critical in multi-drop mode for unique identification of each device.

HART superimposes digital FSK signals onto the analog 4-20 mA loop, allowing both data types to coexist.

The PV represents the main measurement from a field device, such as flow rate in a flow transmitter.

HART devices integrate with SCADA systems, enabling remote monitoring and control in process industries.

“Read Dynamic Variables” provides process values like pressure or temperature in real time, essential for monitoring.

A HART Communicator is a specialized tool that communicates with HART devices to retrieve data and configure settings.

In multi-drop mode, HART devices draw a constant current (fixed at 4 mA), relying on digital communication for data.

HART includes CRC error-checking to verify data integrity, though it lacks advanced encryption.

HART 7 increases device variables to 32, allowing for more detailed diagnostics and asset management.

Common-Practice Commands include calibration functions, such as setting zero and span adjustments.

HART supports up to two masters (primary and secondary), allowing for both local and remote communication.

In a master-slave model, the master controls the communication, prompting the slave (device) to respond only when requested.

HART updates the Primary Variable (PV) as often as every 500 milliseconds in most applications.

Device-Specific Commands control operations unique to a device, unlike Universal Commands that are common across devices.

HART communicates at a speed of 1200 bps using FSK, balancing reliability with low bandwidth requirements.

In multi-drop mode, up to 15 devices can be connected on one loop, each with a unique polling address.

HART uses FSK, where two distinct frequencies represent binary values, enabling digital communication over analog systems.

HART operates over a 4-20 mA current loop, allowing digital signals to be superimposed on the analog signal.

HART enables communication with field devices for remote diagnostics and configuration, often using existing analog wiring.