EmsTechLabs Logo EmsTechLabs

Srne Hf2430U60 Modbus Register 258: Battery Current

Technical documentation for Modbus register 258 on Srne Hf2430U60. Data type: S WORD. Includes Python and YAML configuration examples.

January 16, 2026 3 read

Technical Definition

The register Battery Current at address 258 is used to monitor battery current on the Srne Hf2430U60.

  • Protocol: Modbus RTU
  • Data Type: S 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 Battery Current (Address: 258)
# Note: Check if your device uses 0-based or 1-based addressing
result = client.read_input_registers(address=258, 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: "Battery Current"
  address: 258
  value_type: S_WORD
  unit_of_measurement: "A"

Connection Diagram

Here is the standard RS485 wiring for this configuration:

graph TD
    PLC[Host Controller / Home Assistant]
    Device[Srne Hf2430U60]

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


💡 Engineer's Insight

Analysis: Current flow to or from the battery. Positive for charging, negative for discharging. Units: Amperes (A).

Troubleshooting: Zero means no battery current, indicating charging/discharging is complete or inactive.