Em340 Package Modbus Register 38: modbus controller name sys L-L

Technical Definition

The register modbus controller name sys L-L at address 38 is used to monitor modbus controller name sys l-l on the Em340 Package.

• Protocol: Modbus RTU
• Data Type: S DWORD R
• Unit: V
• 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 modbus_controller_name sys L-L (Address: 38)
# Note: Check if your device uses 0-based or 1-based addressing
result = client.read_input_registers(address=38, 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: "modbus_controller_name sys L-L"
  address: 38
  value_type: S_DWORD_R
  unit_of_measurement: "V"

Connection Diagram

Here is the standard RS485 wiring for this configuration:

graph TD
    PLC[Host Controller / Home Assistant]
    Device[Em340 Package]

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

💡 Engineer's Insight

Analysis: System voltage measured Line-to-Line (L-L). Important for verifying phase balance and supply integrity.

Troubleshooting: Zero indicates a complete loss of voltage or a critical wiring fault.