%5Bssd1306%20128X32%5Denergymeter Modbus Register 79: Frequency

Technical Definition

The register Frequency at address 79 is used to monitor frequency on the %5Bssd1306%20128X32%5Denergymeter.

• Protocol: Modbus RTU
• Data Type: U DWORD
• Unit: Hz
• Access: Read Only

How to Read (Python pymodbus)

Use this code snippet to read this specific value via RS485:

from pymodbus.client.sync import ModbusSerialClient

client = ModbusSerialClient(method='rtu', port='/dev/ttyUSB0', baudrate=9600)
client.connect()

# Read Frequency (Address: 79)
# Note: Check if your device uses 0-based or 1-based addressing
result = client.read_input_registers(address=79, count=2, unit=1)

if not result.isError():
    print(f"Raw Value: {result.registers}")
else:
    print("Error reading register")

client.close()

Integration (Home Assistant)

Paste this into your configuration.yaml:

- platform: modbus_controller
  name: "Frequency"
  address: 79
  value_type: U_DWORD
  unit_of_measurement: "Hz"

Connection Diagram

Here is the standard RS485 wiring for this configuration:

graph TD
    PLC[Host Controller / Home Assistant]
    Device[%5Bssd1306%20128X32%5Denergymeter]

    PLC -- "A+ (D+)" --> Device
    PLC -- "B- (D-)" --> Device
    PLC -- GND --> Device

💡 Engineer's Insight

Analysis: Frequency of the AC power supply in Hertz (Hz). Essential for grid synchronization and motor speed control.

Troubleshooting: Zero value may indicate no power or a device malfunction. Verify power source and device status.