Inverter Modbus Register 315: Friendly name Battery Discharge Limit Current

Technical Definition

The register friendly name Battery Discharge Limit Current at address 315 is used to monitor friendly name battery discharge 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 Discharge Limit Current (Address: 315)
# Note: Check if your device uses 0-based or 1-based addressing
result = client.read_input_registers(address=315, 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 Discharge Limit Current"
  address: 315
  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: Maximum allowed battery discharging current in Amperes (A). Limits discharge rate for battery safety.

Troubleshooting: Zero or low: Temperature limit reached, voltage limit reached, BMS protection active, or communication fault.