Tracer Settings Modbus Register 36893: Line Impedance

Technical Definition

The register Line Impedance at address 36893 is used to monitor line impedance on the Tracer Settings.

• Protocol: Modbus RTU
• Data Type: U WORD
• Unit: mOhm
• 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 Line Impedance (Address: 36893)
# Note: Check if your device uses 0-based or 1-based addressing
result = client.read_input_registers(address=36893, 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: "Line Impedance"
  address: 36893
  value_type: U_WORD
  unit_of_measurement: "mOhm"

Connection Diagram

Here is the standard RS485 wiring for this configuration:

graph TD
    PLC[Host Controller / Home Assistant]
    Device[Tracer Settings]

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

💡 Engineer's Insight

Analysis: Electrical impedance of the connected line or load. Units: Ohms.

Troubleshooting: A value of 0 suggests a short circuit or faulty measurement. Verify line integrity and sensor calibration.