Nilan Cts400 Modbus Register 57: Alarm list 2 info
Technical documentation for Modbus register 57 on Nilan Cts400. Data type: INT16. Includes Python and YAML configuration examples.
January 16, 2026
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Technical Definition
The register Alarm list 2 info at address 57 is used to monitor alarm list 2 info on the Nilan Cts400.
- Protocol: Modbus RTU
- Data Type: INT16
- 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 Alarm list 2 info (Address: 57)
# Note: Check if your device uses 0-based or 1-based addressing
result = client.read_input_registers(address=57, 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: "Alarm list 2 info"
address: 57
value_type: INT16
unit_of_measurement: ""
Connection Diagram
Here is the standard RS485 wiring for this configuration:
graph TD
PLC[Host Controller / Home Assistant]
Device[Nilan Cts400]
PLC -- "A+ (D+)" --> Device
PLC -- "B- (D-)" --> Device
PLC -- GND --> Device
💡 Engineer's Insight
Analysis: Detailed information or status related to the second active alarm. Units depend on the specific alarm code.
Troubleshooting: May indicate an error, be unavailable if no alarm is active, or be a placeholder if the alarm is cleared.