Atom S3 Lite Rs485 Modbus Register 30303: Battery Wifi Signal Strength
Technical documentation for Modbus register 30303 on Atom S3 Lite Rs485. Data type: U WORD. Includes Python and YAML configuration examples.
January 16, 2026
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1 min read
Technical Definition
The register Battery Wifi Signal Strength at address 30303 is used to monitor battery wifi signal strength on the Atom S3 Lite Rs485.
- Protocol: Modbus RTU
- Data Type: U WORD
- Unit: dBm
- 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 Battery Wifi Signal Strength (Address: 30303)
# Note: Check if your device uses 0-based or 1-based addressing
result = client.read_input_registers(address=30303, 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: "Battery Wifi Signal Strength"
address: 30303
value_type: U_WORD
unit_of_measurement: "dBm"
Connection Diagram
Here is the standard RS485 wiring for this configuration:
graph TD
PLC[Host Controller / Home Assistant]
Device[Atom S3 Lite Rs485]
PLC -- "A+ (D+)" --> Device
PLC -- "B- (D-)" --> Device
PLC -- GND --> Device
💡 Engineer's Insight
Analysis: Signal strength of the Wi-Fi connection for battery monitoring. Measured in dBm (decibels relative to one milliwatt).
Troubleshooting: 0 could mean no Wi-Fi connection, device offline, or Wi-Fi disabled. Check network, device power, and settings.