Elga Modbus Register 531: Elga varApplianceOnError
Technical documentation for Modbus register 531 on Elga. Data type: S DWORD. Includes Python and YAML configuration examples.
January 16, 2026
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1 min read
Technical Definition
The register Elga varApplianceOnError at address 531 is used to monitor elga varapplianceonerror on the Elga.
- Protocol: Modbus RTU
- Data Type: S DWORD
- Unit:
- 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 Elga varApplianceOnError (Address: 531)
# Note: Check if your device uses 0-based or 1-based addressing
result = client.read_input_registers(address=531, 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: "Elga varApplianceOnError"
address: 531
value_type: S_DWORD
unit_of_measurement: ""
Connection Diagram
Here is the standard RS485 wiring for this configuration:
graph TD
PLC[Host Controller / Home Assistant]
Device[Elga]
PLC -- "A+ (D+)" --> Device
PLC -- "B- (D-)" --> Device
PLC -- GND --> Device
💡 Engineer's Insight
Analysis: Indicates if the Elga appliance is currently in an error state. Typically a binary value (0=OK, 1=Error).
Troubleshooting: A non-zero value signifies a fault condition requiring investigation.