Test5 Modbus Register 5: Netzteilspannung

Technical Definition

The register Netzteilspannung at address 5 is used to monitor netzteilspannung on the Test5.

• Protocol: Modbus RTU
• Data Type: U WORD
• 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 Netzteilspannung (Address: 5)
# Note: Check if your device uses 0-based or 1-based addressing
result = client.read_input_registers(address=5, 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: "Netzteilspannung"
  address: 5
  value_type: U_WORD
  unit_of_measurement: ""

Connection Diagram

Here is the standard RS485 wiring for this configuration:

graph TD
    PLC[Host Controller / Home Assistant]
    Device[Test5]

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

💡 Engineer's Insight

Analysis: Power Supply Voltage (likely in Volts). The voltage provided by the external power source to the device.

Troubleshooting: Zero if power supply is disconnected, faulty, or no output is detected by the device.