Appendix 2

This Appendix lays down a procedure that may be used by the Technical Service to check tractors and towed vehicles equipped with an electric control line against the functional and performance requirements referred to in point 2.2. of Annex XII.

The references to ISO 7638 within this Appendix apply to ISO 7638-1:2003 for 24V applications and ISO 7638-2:2003 for 12V applications.

The simulator shall:

1. 2.1.1.

   Have a connector meeting ISO 7638:2003 (7 pin) to connect to the vehicle under test. Pins 6 and 7 of the connector shall be used to transmit and receive messages complying with ISO 11992:2003 including ISO 11992-2:2003 and its Amd.1:2007;

2. 2.1.2.

   Be capable of receiving all of the messages transmitted by the motor vehicle to be type approved and be capable of transmitting all towed vehicle messages defined within ISO 11992-2:2003 and its Amd.1:2007;

3. 2.1.3.

   Provide a direct or indirect readout of messages, with the parameters in the data field shown in the correct order relative to time; and

4. 2.1.4.

   Include a facility to measure coupling head response time in accordance with point 2.6 of Annex III.

Confirm that the manufacturer's/supplier's information document demonstrates compliance with the provisions of ISO 11992 with respect to the physical layer, data link layer and application layer.

Check the following, with the simulator connected to the motor vehicle via the ISO 7638 interface and whilst all towed vehicle messages relevant to the interface are being transmitted:

Control line signalling:

1. 2.2.2.1.1.

   The parameters defined in EBS 12 byte 3 of ISO 11992-2:2003 and its Amd.1:2007 shall be checked against the specification of the vehicle as follows:

   This specification of vehicle is prohibited following point 2.1.4.1.3 of Annex I.
   Control Line Signalling	EBS 12 Byte 3
   	Bits 1-2	Bits 5-6
   Service braking demand generated from one electrical circuit	00b
   Service braking demand generated from two electrical circuits	01b
   Vehicle is not equipped with a pneumatic control linef1		00b
   Vehicle is equipped with a pneumatic control line		01b

Service/Secondary brake demand:

1. 2.2.2.2.1

   The parameters defined in EBS 11 of ISO 11992-2:2003 and its Amd.1:2007 shall be checked as follows:

   Optional on tractors with electric and pneumatic control lines when the pneumatic control line fulfils the relevant requirements for secondary braking.
   Test condition	Byte reference	Electrical control line signal value
   Service brake pedal and secondary brake control released	3 - 4	0
   Service brake pedal fully applied	3 - 4	33280d to 43520d (650 to 850 kPa)
   Secondary brake fully appliedf2	3 - 4	33280d to 43520d (650 to 850 kPa)

Failure warning:

1. 2.2.2.3.1.

   Simulate a permanent failure in the communication line to pin 6 of the ISO 7638 connector and check that the yellow warning signal specified in point 2.2.1.29.1.2 of Annex I is displayed.

2. 2.2.2.3.2.

   Simulate a permanent failure in the communication line to pin 7 of the ISO 7638 connector and check that the yellow warning signal specified in point 2.2.1.29.1.2 of Annex I is displayed.

3. 2.2.2.3.3.

   Simulate message EBS 22, byte 2 with bits 3 - 4 set to 01_b and check that the warning signal specified in point 2.2.1.29.1.1 of Annex I is displayed.

Supply line braking request:

For power-driven vehicles which can be operated with towed vehicles connected via an electric control line only:

• Only the electric control line shall be connected.

• Simulate message EBS 22, byte 4 with bits 3 - 4 set to 01_b and check that when the service brake, secondary brake or parking braking system is fully actuated the pressure in the supply line falls to 150 kPa within the following two seconds.

• Simulate a continuous absence of data communication and check that when the service brake, secondary brake or parking braking system is fully actuated the pressure in the supply line falls to 150 kPa within the following two seconds.

Response time:

1. 2.2.2.5.1.

   Check that, with no faults present, the control line response requirements laid down in point 2.6. of Annex III are met.

Simulate message EBS 22 byte 4 bits 5 to 6 set to 00 and check that the stop lamps are not illuminated.

Simulate message EBS 22 byte 4 bits 5 to 6 set to 01 and check that the stop lamps are illuminated.

At the discretion of the Technical Service the checking procedures laid down in points 2.2.1 and 2.2.2 may be repeated with the non-braking functions relevant to the interface in different states or switched off.

Point 2.4.1. of Appendix 1 defines additional messages that shall under specific circumstances be supported by the tractor. Additional checks may be carried out to verify the status of supported messages to ensure the requirements of point 2.3 are fulfilled.

The simulator shall:

1. 3.1.1.

   Have a connector meeting ISO 7638:2003 (7 pin) to connect to the vehicle under test. Pins 6 and 7 of the connector shall be used to transmit and receive messages complying with ISO 11992:2003 including ISO 11992-2:2003 and its Amd.1:2007;

2. 3.1.2.

   Have a failure warning display and an electrical power supply for the towed vehicle;

3. 3.1.3.

   Shall be capable of receiving all of the messages transmitted by the towed vehicle to be type approved and be capable of transmitting all motor vehicle messages defined within ISO 11992-2:2003 and its Amd.1:2007.

4. 3.1.4.

   Provide a direct or indirect readout of messages with the parameters in the data field shown in the correct order relative to time; and

5. 3.1.5.

   Include a facility to measure brake system response time in accordance with point 4.5.2 of Annex III.

Confirm that the manufacturer's or supplier's Information Document, demonstrates compliance with the provisions of ISO 11992:2003 including ISO 11992-2:2003 and its Amd.1:2007 with respect to the physical layer, data link layer and application layer.

Check the following, with the simulator connected to the towed vehicle via the ISO 7638 interface and whilst all tractor messages relevant to the interface are being transmitted:

Service brake system function:

The towed vehicle response to the parameters defined in EBS 11 of ISO 11992-2:2003 and its Amd.1:2007 shall be checked as follows:

The pressure in the supply line at the start of each test shall be ≥ 700 kPa and the vehicle shall be laden (the loading condition may be simulated for the purpose of this check).

For towed vehicles equipped with pneumatic and electric control lines:

• Both control lines shall be connected;

• Both control lines shall be signalled simultaneously;

• The simulator shall transmit message byte 3, bits 5-6;

• Of EBS 12 set to 01_b to indicate to the towed vehicle that a pneumatic control line should be connected.

Parameters to be checked:

Towed vehicles equipped with pneumatic and electric control lines or an electric control line only:

Only the electric control line shall be connected

The simulator shall transmit the following messages:

Byte 3, bits 5-6 of EBS 12 set to 00_b to indicate to the towed vehicle that a pneumatic control line is not available, and byte 3, bits 1-2 of EBS 12 set to 01_b to indicate to the towed vehicle that the electric control line signal is generated from two electric circuits.

Parameters to be checked:

For towed vehicles equipped with only an electric control line, the response to messages defined in EBS 12 of ISO 11992-2:2003 and its Amd.1:2007 shall be checked as follows:

• The pneumatic supply line at the start of each test shall be ≥ 700 kPa.

• The electric control line shall be connected to the simulator.

• The simulator shall transmit the following messages:

  • Byte 3, bits 5-6 of EBS 12 set to 01_b to indicate to the towed vehicle that a pneumatic control line is available.

  • Byte 3-4 of EBS 11 shall be set to 0 (no service brake demand)

The response to the following messages shall be checked:

For towed vehicles connected with only an electrical control line, the response of the towed vehicle to a failure in the electric control transmission of the towed vehicle which results in a reduction in braking performance to at least 30 % of the prescribed value shall be checked by the following procedure:

• The pneumatic supply line at the start of each test shall be ≥ 700 kPa.

• The electric control line shall be connected to the simulator.

• Byte 3, bits 5-6 of EBS 12 set to 00_b to indicate to the towed vehicle that a pneumatic control line is not available.

• Byte 3, bits 1-2 of EBS 12 set to 01_b to indicate to the towed vehicle that the electric control line signal is generated from two independent circuits.

The following shall be checked:

Check that the appropriate warning message or signal is transmitted under the following conditions:

1. 3.2.2.2.1.1.

   Where a permanent failure within the electric control transmission of the towed vehicle braking system precludes the service braking performance being met, simulate such a failure and check that byte 2, bits 3-4 of EBS 22 transmitted by the towed vehicle is set to 01_b. A signal should also be transmitted via pin 5 of the ISO 7638 connector (yellow warning).

2. 3.2.2.2.1.2.

   Reduce the voltage on pins 1 and 2 of the ISO 7638 connector to below a value nominated by the manufacturer which precludes the service braking system performance from being fulfilled and check that byte 2, bits 3-4 of EBS 22 transmitted by the towed vehicle are set to 01_b. A signal should also be transmitted via pin 5 of the ISO 7638 connector (yellow warning).

3. 3.2.2.2.1.3.

   Check compliance with the provisions of point 5.2.4 of this Annex by isolating the supply line. Reduce the pressure in the towed vehicle pressure storage system to the value nominated by the manufacturer. Check that byte 2, bits 3-4 of EBS 22 transmitted by the towed vehicle is set to 01_b and that byte 1, bits 7-8 of EBS 23 is set to 00. A signal should also be transmitted via pin 5 of the ISO 7638 connector (yellow warning).

4. 3.2.2.2.1.4.

   When the electrical part of the braking equipment is first energised check that byte 2, bits 3-4 of EBS 22 transmitted by the towed vehicle is set to 01_b.F1After the braking system has checked that no defects that require identification by the red warning signal are present the message referred to in this point shall be set to 00 _b .

Check that, with no faults present, the braking system response time requirements laid down in point 4.5.2 of Annex III are met.

In case the towed vehicle includes a function where its operation results in an automatically commanded braking intervention, the following shall be checked:

• If no automatically commanded braking intervention is generated, check that message EBS 22 byte 4 bits 5 to 6 are set to 00.

• Simulate an automatically commanded braking intervention, when the resulting deceleration is ≥ 0,7 m/sec², check that message EBS 22 byte 4 bits 5 to 6 are set to 01.

In the case of a towed vehicle equipped with a vehicle stability function, the following checks shall be carried out:

When the vehicle stability function is inactive, check that message EBS 21 byte 2 bits 1 to 2 are set to 00.

Where the towed vehicle braking system does not support braking via the electric control line check that message EBS 22 byte 4 bits 7 to 8 are set to 00.

Where the towed vehicle braking system supports the electric control line, check that message EBS 22 byte 4 bits 7 to 8 are set to 01.

At the discretion of the Technical Service the checking procedures laid down in points 3.2.1 and 3.2.2 may be repeated with the non-braking messages relevant to the interface in different states or switched off.

Where repeat measurements of the brake system response time are carried out, variations in the value recorded may occur due to the reaction of the vehicle pneumatics. In all cases the prescribed response time requirements shall be met.

Point 2.4.2 of Appendix 1 defines additional messages that shall under specific circumstances be supported by the towed vehicle. Additional checks may be carried out to verify the status of supported messages to ensure the requirements of point 2.3 of this Annex are fulfilled.