In an end-to-end industrial telemetry system, which sequence correctly describes the data flow from sensors to alarms?

• A. Data is stored first, then sensors measure.
• B. SCADA to MTU to sensors.
• C. Sensors measure temperature, pressure and flow; signals conditioned and digitized; data transmitted via RF link to a central SCADA/MTU; data stored and displayed on dashboards; alarms triggered on thresholds.
• D. Alarms triggered on thresholds before sensors measure.

Answer: (C)

Data flows from the physical world into a monitoring system in a natural sequence: sensors measure the physical quantities, those signals are conditioned and digitized, the digital data is transmitted to a central SCADA/MTU, then stored and displayed on dashboards, and finally alarms are triggered when readings cross predefined thresholds. This order makes sense because you can’t store or alarm on data that hasn’t been measured and digitized yet, and the central system needs to receive and visualize the data before it can evaluate thresholds to raise alarms. The other descriptions reverse or skip steps (for example, storing data before measurement, alarms before sensing, or routing from the control system back to sensors), which breaks the actual flow of data in an end-to-end telemetry setup.