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A32 Pro Modbus Register 103: S5140 Channel 4 Current (24V) - Air Conditioning

Technical documentation for Modbus register 103 on A32 Pro. Data type: U WORD. Includes Python and YAML configuration examples.

January 16, 2026 1 min read

Technical Definition

The register S5140 Channel 4 Current (24V) - Air Conditioning at address 103 is used to monitor s5140 channel 4 current (24v) - air conditioning on the A32 Pro.

  • Protocol: Modbus RTU
  • Data Type: U WORD
  • Unit: A
  • 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 Channel 4 Current (24V) - Air Conditioning (Address: 103)
# Note: Check if your device uses 0-based or 1-based addressing
result = client.read_input_registers(address=103, 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 Channel 4 Current (24V) - Air Conditioning"
  address: 103
  value_type: U_WORD
  unit_of_measurement: "A"

Connection Diagram

Here is the standard RS485 wiring for this configuration:

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

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


💡 Engineer's Insight

Analysis: Air Conditioning Current (24V). Measured current draw in Amps (A) for the AC unit.

Troubleshooting: Zero means no current. Check AC unit status, fuses, and wiring. Could indicate failure.