A32 Pro Esp32 S3 Modbus Register 100: S5140 Ch 1 Voltage – Fresh‑Water Tank (240‑33 Ω)

Technical Definition

The register S5140 Ch 1 Voltage – Fresh‑Water Tank (240‑33 Ω) at address 100 is used to monitor s5140 ch 1 voltage – fresh‑water tank (240‑33 ω) on the A32 Pro Esp32 S3.

• Protocol: Modbus RTU
• Data Type: U WORD
• Unit: V
• 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 S5140 Ch 1 Voltage – Fresh‑Water Tank (240‑33 Ω) (Address: 100)
# Note: Check if your device uses 0-based or 1-based addressing
result = client.read_input_registers(address=100, 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: "S5140 Ch 1 Voltage – Fresh‑Water Tank (240‑33 Ω)"
  address: 100
  value_type: U_WORD
  unit_of_measurement: "V"

Connection Diagram

Here is the standard RS485 wiring for this configuration:

graph TD
    PLC[Host Controller / Home Assistant]
    Device[A32 Pro Esp32 S3]

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

💡 Engineer's Insight

Analysis: Voltage measurement (in Volts, likely) for Fresh-Water Tank level sensor (S5140 Channel 1).

Troubleshooting: Zero voltage indicates no power, sensor malfunction, or tank empty/full depending on sensor type.