A Guide to Trailer EBS and CANbus

EBS & CANbus
Trailer-EBS-Canbus-cover-300

We have created this document to explain Seven TelematicsÔÇÖ capability for retrieving and presenting data read from a trailerÔÇÖs EBS CANbus, and transmitted to the SevenEye┬« system via Seven TelematicsÔÇÖ trackers.

To print or distribute the document  Download our Guide to Trailer EBS and CANbus PDF here

1.0 Introduction

This document explains Seven TelematicsÔÇÖ capability for retrieving and presenting data read from a trailerÔÇÖs EBS CANbus, and transmitted to the SevenEye┬« system via Seven TelematicsÔÇÖ trackers.

2.0 CANbus Information

The CANbus information thatÔÇÖs available and which is of use within SevenEye┬«, is categorised as follows:

            2.1 Operational

ÔÇó Trailer weight
ÔÇó A single value that represents the static vertical load of the whole trailer and its load (e.g. 10,500 KGs)

            2.2 Maintenance

ÔÇó Electrical Supply Sufficient/Insufficient
ÔÇó Indicates whether the actual supply voltage is sufficient or insufficient for proper function of the brake

ÔÇó Automatic Braking Active
ÔÇó Indicates whether the trailerÔÇÖs pneumatic service brakes have failed and that the spring brakes have automatically been applied

ÔÇó Amber Warning Light Request
ÔÇó Indicates whether the trailer has activated the amber trailer fault warning light in the cab (EBS manufacturer specific)

ÔÇó Red Warning Light Request
ÔÇó Indicates whether the trailer has activated the red trailer fault warning light in the cab (EBS manufacturer specific)

ÔÇó Pneumatic Supply Pressure
ÔÇó The supply pressure of the compressed air in the brake system, (e.g. 870 kPa)

ÔÇó Pneumatic Supply Pressure Sufficient/Insufficient
ÔÇó Whether the EBS thinks the supply pressure (above) is sufficient or sufficient to run the brakes properly

2.3 Driver Style

ÔÇó ABS Active
ÔÇó The number of times the ABS has been activated can be counted, indicating how often the driver has braked hard enough to lock the wheels

3.0 Supported EBSÔÇÖs

The following EBSÔÇÖs can be considered for interfacing to via Seven TelematicsÔÇÖ trackers:

  • Haldex EB+ Gen 2 (2011 onwards) or Gen 3
  • Wabco Type E
  • Knorr-Bremse TEBS G2

4.0 EBS Port

EBS

For this solution to work, there needs to be a spare port supplying CANbus on
the EBS system, to plug a tracker connection into. Typically there is only
one suitable port and itÔÇÖs possible that for any given trailer it is already in use.

An example of a CANbus port (with blanking plug inserted) on a Haldex EB+ Gen 2 EBS is circled in red here:

5.0 EBS Configuration

For Haldex EBS systems, an EBS system parameter that is off by default needs to be
turned on for this solution to work. A Haldex technician can do this. This may also be the case with Wabco and Knorr-Bremse systems.

6.0 Integration within SevenEye®

6.1 SevenEye® Sensor Data

EBS weight data can be seen on the SevenEye® Sensor Data page:

weight-data

A threshold line is shown for the 24 Tonne limit for trailers.

An over-weight email or SMS alert can be set up if required

6.2 SevenEye® Daily Trailer Activity Report

Other EBS data is presented within the SevenEye® Daily Trailer Activity Report, in conjunction with GPS data and TranScan® data:

daily-trailer-activity-980

7.0 Explanatory Notes

Distance
This is the total distance travelled by the trailer for the day, as measured by GPS calculations.

Utilisation
This is the duration between the first Journey Start of the day and the last Journey End of the day, divided into 24 hours, and expressed as a percentage.

Empty Running
This is calculated using the total trailer weight value provided via the trackerÔÇÖs CANbus connection to trailerÔÇÖs EBS.

All weight readings are used from when the trailer was in journeys, and the number of weight readings greater than 6,000 Kgs (=> loaded) is divided into the total number of weight readings.

The resulting percentage is %Loaded, and 100 minus that figure is %Unloaded.

Temperature
All readings from TranScan temperature probes for the day are shown here.

Weight
All trailer weight readings from the trackerÔÇÖs CANbus connection to the trailerÔÇÖs EBS are shown here.

Journey Log
This lists all journeys for the day that were at least 1 mile long. The latest temperatures and weight at the time of each Journey End are included.

EBS Monitoring
This section shows the most meaningful data available via the trackerÔÇÖs CANbus connection to the trailerÔÇÖs EBS (i.e. in addition to weight). It is understood that this data is available for each of the latest Haldex, Wabco & Knorr-Bremse EBSs.

The EBS Monitoring values are colour-coded green, amber & red, to indicate whether a value implies: normal running (green), a warning situation (amber) or a definite problem (red).

Amber Warning Light Activations
EBS systems have the ability to signal an amber warning light in the towing tractor unit. This value counts the number of amber warning light activations for the day.

Red Warning Light Activations
EBS systems have the ability to signal a red warning light in the towing tractor unit. This value counts the number of red warning light activations for the day.

Electrical Supply Sufficient
This value indicates whether the EBS thinks the electrical supply voltage to the EBS is sufficient to operate the trailerÔÇÖs brakes correctly.

Pneumatic Supply Pressure
This is the average pneumatic supply pressure reading read from the EBS whilst the trailer was in journeys.

Pneumatic Supply Pressure Sufficient
This value indicates whether the EBS thinks pneumatic supply pressure is sufficient to operate the trailerÔÇÖs brakes correctly.

ABS Activations
This value counts the number of times the antilock brakes were engaged during the day, to prevent its wheels from locking whilst braking.

Note that the first 5 metrics above are maintenance related, whereas the last is an indication of driver style.