EmsTechLabs Logo EmsTechLabs

Schundmeter Modbus Register 380: Chint power factor phase 1

Technical documentation for Modbus register 380 on Schundmeter. Data type: S WORD. Includes Python and YAML configuration examples.

January 16, 2026 1 min read

Technical Definition

The register chint power factor phase 1 at address 380 is used to monitor chint power factor phase 1 on the Schundmeter.

  • Protocol: Modbus RTU
  • Data Type: S WORD
  • Unit: cosphi
  • 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 chint power factor phase 1 (Address: 380)
# Note: Check if your device uses 0-based or 1-based addressing
result = client.read_input_registers(address=380, 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: "chint power factor phase 1"
  address: 380
  value_type: S_WORD
  unit_of_measurement: "cosphi"

Connection Diagram

Here is the standard RS485 wiring for this configuration:

graph TD
    PLC[Host Controller / Home Assistant]
    Device[Schundmeter]

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


💡 Engineer's Insight

Analysis: Power factor for phase 1 (unitless). Ratio of real to apparent power in phase 1.

Troubleshooting: Zero indicates minimal or no real power consumption in phase 1. Low values may signal motor issues or phase imbalance.