METER Group · Weather station
ATMOS 41 Gen 2 (Modbus RTU enabled) Modbus register map
Default configuration
- Protocol
- RS485
- Port
- 502
- Unit ID
- 1
- Addressing
- 1-based
- Byte order
- Big endian
- Word order
- High word first
- Baud rate
- 9600
- Parity
- Even
- Data bits
- 8
- Stop bits
- 1
This device has an RS-485 interface. Reach it through a Modbus RTU-to-TCP gateway, configured with the factory serial settings above.
Register map
| Address | Count | Name | Type | Unit | Scale | Access |
|---|---|---|---|---|---|---|
| 3001 | 2 | Solar radiation Average solar radiation since the last measurement. Register number 3001 in the vendor table; the PDU address is 3000 (see notes on addressing). | Float32 | W/m2 | 1 | R |
| 3003 | 2 | Total precipitation Total combined rainfall from the dual rain gauges since the last measurement. | Float32 | mm | 1 | R |
| 3005 | 2 | Precipitation drop counter Total rain drops detected by the drop counter since the last measurement (count, 0-65535). | Float32 | - | 1 | R |
| 3007 | 2 | Precipitation tip counter Total precipitation tipping-spoon tips since the last measurement (count, 0-65535). | Float32 | - | 1 | R |
| 3009 | 2 | Precipitation electrical conductivity Average precipitation basin bulk EC since the last measurement. Reads 0 if no tipping-spoon tips were detected since the last measurement. | Float32 | µS/cm | 1 | R |
| 3011 | 2 | Lightning strike count Total lightning strikes since the last measurement (count, 0-65535). | Float32 | - | 1 | R |
| 3013 | 2 | Average lightning strike distance Average strike distance from the sensor since the last measurement; 0 when no strikes were detected. | Float32 | km | 1 | R |
| 3015 | 2 | Wind speed Average wind speed magnitude since the last measurement (0.00-60.00 m/s). | Float32 | m/s | 1 | R |
| 3017 | 2 | Wind direction Average wind heading clockwise from north (0.0-359.9 deg) since the last measurement. | Float32 | ° | 1 | R |
| 3019 | 2 | Gust wind speed Maximum wind speed magnitude seen since the last measurement (0.00-60.00 m/s). | Float32 | m/s | 1 | R |
| 3021 | 2 | Air temperature Average air temperature since the last measurement (-65.0 to 60.0 °C). | Float32 | °C | 1 | R |
| 3023 | 2 | Vapor pressure Average vapor pressure since the last measurement (1.00-47.00 kPa). | Float32 | kPa | 1 | R |
| 3025 | 2 | Atmospheric pressure Average atmospheric pressure since the last measurement (1.00-120.00 kPa). | Float32 | kPa | 1 | R |
| 3027 | 2 | Relative humidity Average relative humidity since the last measurement as a fraction: 0.000-1.000, i.e. multiply by 100 for %. The vendor table gives the unit as '% / 100'. | Float32 | - | 1 | R |
| 3029 | 2 | Humidity sensor temperature Average temperature of the relative-humidity sensor since the last measurement (-40.0 to 85.0 °C). | Float32 | °C | 1 | R |
| 3031 | 2 | Single-value orientation Average sensor polar orientation since the last measurement (0.0-180.0 deg). | Float32 | ° | 1 | R |
| 3033 | 2 | Minimum air temperature Lowest air temperature seen since the last measurement (-65.0 to 60.0 °C). | Float32 | °C | 1 | R |
| 3035 | 2 | Maximum air temperature Highest air temperature seen since the last measurement (-65.0 to 60.0 °C). | Float32 | °C | 1 | R |
| 3037 | 2 | North wind speed Average wind speed from a northerly direction since the last measurement (-60.00 to 60.00 m/s). | Float32 | m/s | 1 | R |
| 3039 | 2 | East wind speed Average wind speed from an easterly direction since the last measurement (-60.00 to 60.00 m/s). | Float32 | m/s | 1 | R |
| 3041 | 2 | X-direction orientation Average sensor orientation in the X direction since the last measurement (-90.0 to 90.0 deg). | Float32 | ° | 1 | R |
| 3043 | 2 | Y-direction orientation Average sensor orientation in the Y direction since the last measurement (-90.0 to 90.0 deg). | Float32 | ° | 1 | R |
| 3401 | 1 | Sensor type Sensor type number; 88 for the ATMOS 41 Gen 2. | UInt16 | - | 1 | R |
| 3402 | 2 | Sensor numeric serial number Numeric part of the serial number, i.e. the XXXXXXX in A41G2MXXXXXXX. | UInt32 | - | 1 | R |
| 3404 | 1 | Sensor firmware version METER digital-sensor firmware version; divide by 100 for the version number (e.g. 608 = 6.08). | UInt16 | - | 1 | R |
| 3405 | 1 | Sensor build version Firmware build/patch version. Appended to the firmware version it forms the full version (e.g. 16 appended to 6.08 is 6.08.16). | UInt16 | - | 1 | R |
| 3406 | 1 | Sensor hardware revision Hardware revision number, indicating hardware version and capabilities. | UInt16 | - | 1 | R |
| 3419 | 7 | Sensor ASCII serial number Full serial number as a 13-character ASCII string plus one null terminator (A41G2MXXXXXXX), packed into 7 registers. | Ascii | - | 1 | R |
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Related guides
Notes
Source: METER Group 'ATMOS 41 Gen 2 Integrator Guide', document 18036-03, edition 01.2025 — sensor description, Table 20 (Modbus communication configuration), section 'Data representation and registers', Table 23 (holding registers), Table 24 (input register measurement map, register numbers 3001-3044) and Table 25 (identity registers 3401-3425). The guide is the integration document for the Modbus RTU enabled variant of the ATMOS 41 Gen 2 all-in-one weather station (serial numbers A41G2M...); SDI-12-only units (serial A41G2...) do not serve this map. Addressed as printed: the guide states that registers are listed with their 1-based register number and that the address in a Modbus PDU is the register number minus 1, so the printed numbers are stored with addressing = one_based. 32-bit values are big-endian with the most significant word first (Table 22), hence byte_order BigEndian and word_order HighFirst. Factory frame from Table 20 and the text below it: 9600 baud, 8 data bits, even parity, 1 stop bit, server address 1. Note the reader semantics: a read of the measurement input registers resets the sensor's averaging counters/accumulators for all measurements, even the ones not read, which is why the guide recommends a single burst read of the whole 3001-3044 block. Deliberately omitted: the 3407-3418 model string (UTF-16 array, no Ascii encoding of UTF-16 in the app) and registers below 3001/above 3425 (none documented). Not seeded: the SDI-12 register view and the CR6 datalogger example, which are not part of the Modbus map. MIRROR-SOURCED: metergroup.com answers automated requests with HTTP 403, so the 18036-03 copy read here is the distributor mirror https://candh.co.kr/upload/1784693309_6.pdf (vendor document title/edition unchanged; sha256 94d5929806fc30fd4216eb67e2babda0352a873b7083aef7137cd016fb7c641d).