All Modbus Register 1000: Actual on/off state

Technical Definition

The register Actual on/off state at address 1000 is used to monitor actual on/off state on the All.

• 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 Actual on/off state (Address: 1000)
# Note: Check if your device uses 0-based or 1-based addressing
result = client.read_input_registers(address=1000, 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: "Actual on/off state"
  address: 1000
  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[All]

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

💡 Engineer's Insight

Analysis: Current operational status of the device or function. Units: Boolean (0=Off, 1=On).

Troubleshooting: Zero may indicate a stop command, safety interlock, or power failure. Verify control signals and power supply.