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Sdm630 Modbus Register 8: Device name L2 Current

Technical documentation for Modbus register 8 on Sdm630. Data type: FP32. Includes Python and YAML configuration examples.

January 16, 2026 1 min read

Technical Definition

The register device name L2 Current at address 8 is used to monitor device name l2 current on the Sdm630.

  • Protocol: Modbus RTU
  • Data Type: FP32
  • 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 device_name L2 Current (Address: 8)
# Note: Check if your device uses 0-based or 1-based addressing
result = client.read_input_registers(address=8, 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: "device_name L2 Current"
  address: 8
  value_type: FP32
  unit_of_measurement: "A"

Connection Diagram

Here is the standard RS485 wiring for this configuration:

graph TD
    PLC[Host Controller / Home Assistant]
    Device[Sdm630]

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


💡 Engineer's Insight

Analysis: Phase L2 current reading. Unit: Amperes (A). Measures electrical current flowing through phase L2.

Troubleshooting: Zero value could mean no load on L2, a broken conductor, or a faulty current transformer/sensor. Verify load and wiring.