Introduction to the BSS10 firmware

New algorithm highlights

• The new algorithm will improve the sensor's ability to better recognize bearing failures and avoid false positives.
• This algorithm is compatible with every type of axle (i.e. driven axles included!).
• This algorithm is trained on the vehicle wheel end during a learning phase which takes about 55 hours. Gone is the requirement of earlier firmware generations for a calibration process that spanned several months.
• The confidence level on wheel end failure detection is improved to 95%.

Sensor data

To make it easier for TSPs to map sensor statuses to the urgency of acting, we´ve put together an article that outlines general guidelines for Acting on sensor data.

Temperature warning

We've added a temperature alarm directly into the TraX sensor, complete with visual LED indicators and Mobile App status. The temperature measurement is checked against a predefined temperature threshold. If this temperature is above the threshold for the defined period, an alarm is triggered.

Similar to other failure statuses such as battery level or wheel end failure, the new temperature warning status is provided in the failure byte. For complete instructions, please review the technical spec: TraX - WEM200 - Technical Specification Connected

To make it easy for TraX implementors to test the new temperature warning field, we´ve updated the set of sensor data samples described in the Sensor data integration, with samples that include the new temperature warning status.

Vibration monitoring status

Sensors running BSS10 firmware need to complete a learning phase. After 39 measurements, the algorithm model is calculated, and the vibration monitoring is active. To be clear, the ability to detect wheel end failure based on vibration monitoring is only available for sensors that have completed the learning phase. Other measurements, such as temperature warnings, are still available.

TSPs can determine the vibration monitoring status by decoding the last byte using bitmask 0xC0. Below is a list of the available vibration monitoring statuses:

0. Vibration monitoring active
1. Learning phase complete
2. Learning phase ongoing
3. Inconsistent data

Firmware version

Since the temperature warning and vibration monitoring status are new features that are exclusive to firmware BSS10, TSPs need a way to determine whether to parse sensor data according to the BSS08 frame format, or the recent BSS10 frame format.

The firmware version is located in the second byte from the end. It's a hex value that needs to be converted to a decimal value.

The first digit represents the main BSS version, and the second digit is the corrective version. The corrective version needs to be mapped to a character, where the digit 1 = a, 2 = b, 3 = c ... and …9 = i.

For example, hex 0x54 translates to decimal 84, where "8" is the main BSS version, and "4" needs to be translated to the 4:th character in the alphabet, i.e. "d". So 0x54 translates to firmware version 8d (0x54 -> 84 -> 8d)

Sensor data frame format

The sensor data referred to in this article has been marked in bold. Note that the byte "Health status" is used for other statuses as well, in both BSS08 and BSS10.

BSS10 frame format

02 01 06 0A 09 57 45 4D 46 46 46 46 31 44 10 FF 0E 04 21 21 47 16 8A 00 00 00 00 00 00 00 00
── ── ── ── ── ──────── ───────────────── ── ── ───── ── ── ── ── ── ── ────────────── ── ──
|  |  |  |  |      |          |           |  |    |    |  |  |  |  |  |        |        |  |
|  |  |  |  |      |          |           |  |    |    |  |  |  |  |  |        |        |  |___ algoStatus
|  |  |  |  |      |          |           |  |    |    |  |  |  |  |  |        |        |__ Fw version
|  |  |  |  |      |          |           |  |    |    |  |  |  |  |  |        |
|  |  |  |  |      |          |           |  |    |    |  |  |  |  |  |        |
|  |  |  |  |      |          |           |  |    |    |  |  |  |  |  |        |_______ Debug data
|  |  |  |  |      |          |           |  |    |    |  |  |  |  |  |
|  |  |  |  |      |          |           |  |    |    |  |  |  |  |  |
|  |  |  |  |      |          |           |  |    |    |  |  |  |  |  |_______________ Frame Counter
|  |  |  |  |      |          |           |  |    |    |  |  |  |  |__________________ Tmax
|  |  |  |  |      |          |           |  |    |    |  |  |  |_____________________ Tmin
|  |  |  |  |      |          |           |  |    |    |  |  |________________________ Tcurrent
|  |  |  |  |      |          |           |  |    |    |  |__________ Position 2 | Axle 1
|  |  |  |  |      |          |           |  |    |    |_____________ Battery 2 | Health status 1
|  |  |  |  |      |          |           |  |    |___________ 0E 04 = Company Identifier code
|  |  |  |  |      |          |           |  |________________ FF = manufacturer specific data
|  |  |  |  |      |          |           |___________________ 10 = manufacturer data length
|  |  |  |  |      |          |________________ 46 46 46 46 31 44 “FFFF1D” End of MAC address
|  |  |  |  |      |_________________________ 57 45 4D = "WEM", zero terminated string
|  |  |  |  |__________________________________ 09 = local name
|  |  |  |_____________________________________ 0A = local name length
|  |  |________________________________________ Device in general discoverable mode | Only BLE supported
|  |___________________________________________ 01 = advertising
|______________________________________________ length

Reset with a magnet

In addition to using the Mobile App, we've introduced a handy new feature that allows you to reset the sensor using a magnet. This simplifies sensor management for fleet operators, providing more flexibility and convenience.

Other advertisement frame changes

The sensor will now broadcast data for a longer period (increased by 100%) to lower the risk of sensor data packet loss.

References

TraX - WEM200 - Technical Specification Connected

FAQ

What is the duration of the learning phase for the new BSS10 before it can detect a wheel end failure?

The learning phase for the BSS10 involves the TraX sensor operating under normal vehicle conditions at a minimum speed of 40 MPH for at least 55 hours.

When can you determine that the learning phase for the TSP is complete?

The last byte in the BLE advertising frame indicates the algorithm's status in the learning phase but requires decoding for information access.

Is it possible to reset or reconfigure the sensor to initiate a new learning phase?

Yes, you can reset or reconfigure the sensor.

Is recalibrating the sensor necessary for different seasons? For instance, if the learning phase occurred during the summer, is it required again in the winter?

No, it is not necessary.

Does the sensor have a default value before it establishes its value following the learning phase? If so, what is the default value?

No, there is no default value.

Does the sensor function and provide alerts during its learning phase?

The sensor is operational and analyzes vibrations to create the algorithm model. The wheel end failure cannot be set during this phase. Other failures, like temperature warnings or internal failures, are operational and can provide alerts.