Inverter Modbus Register 314: Friendly name Battery Charge Limit Current

Technical Definition

The register friendly name Battery Charge Limit Current at address 314 is used to monitor friendly name battery charge limit current on the inverter.

• 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 friendly_name Battery Charge Limit Current (Address: 314)
# Note: Check if your device uses 0-based or 1-based addressing
result = client.read_input_registers(address=314, 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: "friendly_name Battery Charge Limit Current"
  address: 314
  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[inverter]

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

💡 Engineer's Insight

Analysis: Sets the maximum current allowed for charging the battery. Units are typically Amperes (A). Essential for battery longevity and safety.

Troubleshooting: Zero value means no charging is permitted. Check charging source, battery state, and configuration settings. May indicate a fault preventing charge.