Bms Test Modbus Register 4924: Bat2 Temp Sensor 3

Technical Definition

The register Bat2 Temp Sensor 3 at address 4924 is used to monitor bat2 temp sensor 3 on the Bms Test.

• Protocol: Modbus RTU
• Data Type: U WORD
• Unit: °C
• 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 Bat2 Temp Sensor 3 (Address: 4924)
# Note: Check if your device uses 0-based or 1-based addressing
result = client.read_input_registers(address=4924, 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: "Bat2 Temp Sensor 3"
  address: 4924
  value_type: U_WORD
  unit_of_measurement: "°C"

Connection Diagram

Here is the standard RS485 wiring for this configuration:

graph TD
    PLC[Host Controller / Home Assistant]
    Device[Bms Test]

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

💡 Engineer's Insight

Analysis: Temperature reading from the third sensor on Battery 2. Units: Degrees Celsius (°C).

Troubleshooting: Unusual readings (high/low) could signal a faulty sensor, poor thermal contact, or environmental issues. Zero may indicate sensor failure.