Esp32 Srne Asf Example Modbus Register 532: Grid Current A

Technical Definition

The register Grid Current A at address 532 is used to monitor grid current a on the Esp32 Srne Asf Example.

• Protocol: Modbus RTU
• Data Type: U WORD
• Unit: A
• 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 Grid Current A (Address: 532)
# Note: Check if your device uses 0-based or 1-based addressing
result = client.read_input_registers(address=532, 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: "Grid Current A"
  address: 532
  value_type: U_WORD
  unit_of_measurement: "A"

Connection Diagram

Here is the standard RS485 wiring for this configuration:

graph TD
    PLC[Host Controller / Home Assistant]
    Device[Esp32 Srne Asf Example]

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

💡 Engineer's Insight

Analysis: Measured AC current flowing from the inverter to the grid, typically in Amperes (A). Reflects power output.

Troubleshooting: Zero implies no power generation or a fault in current sensing. High values may indicate overload.