Document ID: chunk:federal_register_of_legislation:F2025C00113:reg:4:p8
Version: federal_register_of_legislation:F2025C00113
Segment Type: reg
Provision Reference: reg 4 (pt 8/10)
Character Range: 91664–94851

during 'Selective Braking' initiated by the trailer (note: during a 'Selective Braking' event, the function may change to 'Automatically Commanded Braking').
 1.                            The data contacts of an ISO 7638 connector incorporating an electric 'Control Line' must be used to transfer information exclusively for braking (including the 'Vehicle Stability Function' and 'Antilock System') and running gear (steering, tyres and suspension) functions as specified in ISO 11992‑2:2003 including its amendment 1:2007.
     1.                     The braking functions have priority and must be maintained in the normal and failed modes.  The transmission of running gear information must not delay braking functions.
 2.                            The overall length of the electric 'Control Line' installed within a trailer may exceed the 18 m permitted by ISO 11992‑1:2013, where a device (e.g. CAN repeater) is installed to amplify and repeat messages in such a way that all communications throughout the electric 'Control Line' otherwise conform with ISO 11992‑1:2003 and ISO 11992‑2:2003 including its amendment 1:2007.
 3.                            A message routing device/function (e.g. CAN router) conforming to ISO 11992‑2:2003, paragraph 6.3 (Message Routing), is required for all trailers incorporating electric 'Control Line' through which messages are distributed between more than two electronic nodes (e.g. trailers for which multiple control units are used to provide the braking functions required by clause 7.2 of this standard).  Such a device/function is necessary to satisfy the point‑to‑point type requirement for the electric 'Control Line' between electronic devices.

 1.                                  Additional requirements for all trailers equipped to tow another trailer with an 'ATM' greater than 4.5 tonnes
     1.                            Except as provided in clause 3.1.1 below, each trailer (including any 'Converter Dolly') equipped to tow another trailer with an 'Aggregate Trailer Mass (ATM)' greater than 4.5 tonnes, must be fitted at the rear with a connector conforming to ISO 7638‑1:2003 and meeting the requirements of clause 1.2 of this appendix.[4]  This connector must be configured to distribute a 24 volt electrical supply, received via a connector in accordance with ISO 7638‑1:2003 at the front of the trailer, to a 'Vehicle Stability Function' and/or the 'Antilock Systems' of a towed trailer.[5]
         1.                     A 'Semi-trailer' that is equipped with a 'Fifth Wheel Coupling' towards the rear (i.e. an A-trailer / Lead-trailer) and is not designed for use in 'Road Train' combinations, may be fitted with a connector conforming to ISO 7638‑2:2003 in place of the 24 volt connector otherwise required above.  This connector must be configured to distribute a 12 volt electrical supply, received via a connector in accordance with ISO 7638‑2:2003 at the front of the trailer, to a towed trailer.
     2.                            The continuous current capacity of the electrical conductive material through which current flows between the contacts of the ISO 7638 connectors[6] at the front and rear of a