SLUUDN8 July   2026 TMS320F28P550SJ , TMS320F28P650DK

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
  5. 2Library Notice
  6. 3Library Architecture
    1. 3.1 Background Processing
    2. 3.2 Foreground Processing
    3. 3.3 Data Transfer Mechanism
  7. 4Metrology Calculations
  8. 5Configuration and Data Structures
  9. 6Calibration Module
  10. 7User Specific Configurations
    1. 7.1 Debug Mode
      1. 7.1.1 The Function of Debug Mode
      2. 7.1.2 How to Configure DEBUG Mode Parameters
    2. 7.2 ADC Mode
      1. 7.2.1 Using the On-Chip ADC
      2. 7.2.2 Two Point Calibration
        1. 7.2.2.1 Step 1 – Offset Calibration (Zero-Input Point)
        2. 7.2.2.2 Step 2 – Gain Calibration (Full-Scale Point)
      3. 7.2.3 Using an External ADC
    3. 7.3 Switching Between Modes
    4. 7.4 THD Algorithm Selection
      1. 7.4.1 Method 1 – Based on PLL (Default When the HARMONICS_SUPPORT Macro is Not Defined)
      2. 7.4.2 Method 2 – Goertzel DFT (When the HARMONICS_SUPPORT and USE_GOERTZEL_THD Macros are Both Defined)
      3. 7.4.3 Method 3 – 2048-Point Real FFT (When the HARMONICS_SUPPORT Macro is Defined But the USE_GOERTZEL_THD Macro is Not)
    5. 7.5 Topology Selection
    6. 7.6 Enable Features
    7. 7.7 System Parameters
    8. 7.8 Scaling Factors Per Phase
  11. 8Running the Example
    1. 8.1 Accessing the Parameters Per Phase
    2. 8.2 Accessing the Total System Measurements
    3. 8.3 Accessing the Phase Status Flags

5 Configuration and Data Structures

These files define constants (for example, nominal voltage or frequency, or sample rates), preprocessor macros for feature enablement (for example, HARMONICS_SUPPORT and NEUTRAL_MONITOR_SUPPORT), and the critical data structures that hold all information related to metrology.

  • metrologyData: The top-level global structure, an instance of which holds all data for all phases, neutral, totals, and system status.
  • phaseMetrology or neutralMetrology: Structures within metrologyData containing parameters (params) and readings (readings) for each phase and the neutral line.
    • params: Stores configuration, intermediate accumulations from background (like dotProd arrays), calibration-derived values, and state variables (for example, for PLL, and sag and swell).
    • readings: Stores the final calculated metrology values (RMS, power, PF, and so forth).
  • calibrationData (metrology_nv_structs.h): Holds the calibration coefficients.