TIDUF98A October   2024  – February 2025

 

  1.   1
  2.   Description
  3.   Resources
  4.   Features
  5.   Applications
  6.   6
  7. 1System Description
    1. 1.1 End Equipment
      1. 1.1.1 Electricity Meter
    2. 1.2 Key System Specifications
  8. 2System Overview
    1. 2.1 Block Diagram
    2. 2.2 Highlighted Products
      1. 2.2.1 ADS131M03
      2. 2.2.2 MSPM0L2228
      3. 2.2.3 THVD1400
      4. 2.2.4 ISO6731
      5. 2.2.5 DRV5032
    3. 2.3 Design Considerations
      1. 2.3.1 Design Hardware Implementation
        1. 2.3.1.1 Analog Inputs
          1. 2.3.1.1.1 Voltage Measurement Analog Front End
          2. 2.3.1.1.2 Current Measurement Analog Front End
      2. 2.3.2 Energy Metrology Software
        1. 2.3.2.1 Software Architecture
        2. 2.3.2.2 Setup
          1. 2.3.2.2.1 Clocking Scheme
          2. 2.3.2.2.2 SPI
          3. 2.3.2.2.3 UART Setup for GUI Communication
          4. 2.3.2.2.4 Real-Time Clock
          5. 2.3.2.2.5 LCD Controller
          6. 2.3.2.2.6 Direct Memory Access
    4. 2.4 Hardware, Software, Testing Requirements, and Test Results
      1. 2.4.1 Required Hardware and Software
        1. 2.4.1.1 Cautions and Warnings
        2. 2.4.1.2 Hardware
          1. 2.4.1.2.1 Connections to the Test Setup
          2. 2.4.1.2.2 Power Supply Options and Jumper Settings
        3. 2.4.1.3 Calibration
      2. 2.4.2 Testing and Results
        1. 2.4.2.1 Test Setup
          1. 2.4.2.1.1 Viewing Metrology Readings and Calibration
            1. 2.4.2.1.1.1 Viewing Results From LCD
            2. 2.4.2.1.1.2 Viewing Results From PC GUI
        2. 2.4.2.2 Electricity Meter Metrology Accuracy Testing
        3. 2.4.2.3 Electricity Meter Metrology Accuracy Results
  9. 3Design Files
    1. 3.1 Schematics
    2. 3.2 Bill of Materials
    3. 3.3 PCB Layout Recommendations
      1. 3.3.1 Layout Prints
    4. 3.4 Altium Project
    5. 3.5 Gerber Files
    6. 3.6 Assembly Drawings
  10. 4Related Documentation
    1. 4.1 Trademarks
  11. 5About the Authors
  12. 6Revision History
2.4.2.1.1.2 Viewing Results From PC GUI

To view the metrology parameter values from the GUI, perform the following steps:

  1. Select whether to use the RS-485 or UART connection for communication to the PC GUI. The testing was done using UART with 9600, 8N1 setting on pins PA8 and PA9.
  2. Connect the reference design to a PC:
    • UART option: Connect the reference design to a PC using a UART cable, wired to pins PA8 and PA9, or pin 22 and 23, respectively. Blue wires to pins 4 and 5 of U11, which is the RS-485 isolation device, are used in this case.
    • RS-485 option: Use a USB to RS-485 adapter to communicate between the PC GUI and the RS-485 port on this design. The USB to RS-485 adapter needs to create a COM port on the PC when plugged in. The other end of the adapter needs to have wires for the RS-485 Data A and Data B connections as well as a GND connection and a 3.3V power connection.
  3. Open the GUI folder and open calibration-config.xml in a text editor.
  4. Change the port name field within the meter tag to the COM port connected to the system. As Figure 2-7 shows, this field is changed to COM7.
    TIDA-010940 GUI Configuration File Changed to Communicate With Energy Measurement System Figure 2-7 GUI Configuration File Changed to Communicate With Energy Measurement System
  5. Run the calibrator.exe file, which is located in the GUI folder. If the COM port in the calibration-config.xml was changed in the previous step to the COM port connected to the reference design, the GUI opens (see Figure 2-8). If the GUI connects to the design properly, the top-left button is green. If there are problems with connections or if the code is not configured correctly, the button is red. Click the green button to view the results.
    TIDA-010940 GUI Startup Window Figure 2-8 GUI Startup Window

When clicking the green button, the results window opens (see Figure 2-9). In the figure, there is a trailing "L" or "C" on the Power factor values to indicate an inductive or capacitive load, respectively. Note that by default, the column in the GUI labeled "Phase A" is actually the shunt channel and the column labeled "Neutral" is actually the CT channel. If the system and shunt is referenced with respect to the neutral, the shunt can actually measure the neutral current and the CT can measure the line current, unlike how the GUI is labeled.

TIDA-010940 GUI Results Window Figure 2-9 GUI Results Window

From the results window, the total-energy consumption readings can be viewed by clicking the Meter Consumption button. After the user clicks this button, the Meter events and consumption window pops up, as Figure 2-10 shows.

TIDA-010940 Meter Events and Consumption Window Figure 2-10 Meter Events and Consumption Window

From the results window, the meter settings can be viewed by clicking the Meter features button, view the system calibration factors by clicking the Meter calibration factors button, or open the window used for calibrating the system by clicking the Manual cal. button.