B3 Report
Compact TAU binary report of 47 bytes that packs GPS position, device status and cell data into a single frame. It is designed to reduce the transmitted data volume: about 70% less than the equivalent text report.
TAU binary reports (B3 and B9) are assigned to events just like text reports (type CQ / CY). The device encodes and transmits them directly in binary.
What is it for?
- 📉 Minimize mobile data usage across large fleets
- 🛰️ Satellite / LPWA links where every byte counts
- 📍 Position report with network and cell status in a single frame
- 🔋 Shorter transmissions = lower modem energy consumption
Event assignment
The report is assigned to an event with the two-letter code B3, exactly like the text reports CQ or CY. When the event fires, the device builds the 47-byte binary frame and sends it to the configured destination.
SMS is not a valid destination for binary reports. If the assigned destination is SMS, the frame is discarded (binary is not transmitted over SMS). Use GPRS, Wi-Fi, backend or log.
Terminal query (QBUS)
When querying the buffer from the terminal with QBUS, the frame is shown as a hex dump with the RB3: prefix.
>QBUS<
>RB3:3E52423368...< // 47 bytes in hexadecimalBinary layout (47 bytes)
| Bytes | Field | Description |
|---|---|---|
| 0–3 | Header | ASCII >RB3 |
| 4–7 | Date/time | TAU epoch (uint32, big-endian) |
| 8 | Event | Event code that triggered the report |
| 9–12 | HDOP + longitude | HDOP (6 bits) + 26-bit TAU longitude (lon × 10⁵ + 18000000) |
| 13–16 | Fix + satellites + latitude | Fix (2 bits) + satellites (4 bits) + 25-bit TAU latitude (lat × 10⁵ + 9000000) |
| 17 | Position age | Seconds since last valid fix (max. 255) |
| 18–19 | GSM signal + speed | CSQ (6 bits) + speed km/h (10 bits) |
| 20–21 | Network registration + heading | GSM/GPRS registration (3 + 3 bits) + heading in degrees (9 bits) |
| 22–23 | Outputs + inputs | Digital outputs XP (5 bits) + inputs IN (10 bits) |
| 24–25 | Power + battery | GPS/CEL status + battery voltage (12 bits) |
| 26–29 | Odometer | Total odometer (uint32, big-endian) |
| 30 | Backup battery | LiPo level mapped to 0–100% |
| 31 | Network technology | -90 no network, -91 2G, -92 3G, -93 4G LTE, -94 Cat-M1, -95 Cat-NB1 |
| 32–33 | MCC | Mobile Country Code (uint16, big-endian) |
| 34–35 | MNC | Mobile Network Code (uint16, big-endian) |
| 36–37 | LAC | Location Area Code (uint16, big-endian) |
| 38–39 | Cell ID | Cell identifier (uint16, big-endian) |
| 40–43 | Device ID | Device identifier (4 bytes) |
| 44–45 | Message number | Message counter (uint16, big-endian) |
| 46 | Checksum | XOR of bytes 0–45 |
Coordinates: latitude and longitude are transmitted with a TAU offset (lat × 10⁵ + 9000000, lon × 10⁵ + 18000000) to avoid the sign. The network technology field uses negative values as the RAT identifier.