ISO 16844-3:2022

Road vehicles — Tachograph systems — Part 3: Motion sensor communication interface

This document specifies the communication interface between motion sensor and recording equipment. This includes the mechanical, electrical and logical requirements.

Véhicules routiers — Systèmes tachygraphes — Partie 3: Interface de communication pour capteur de mouvement

General Information

• Status: Published
• Publication Date: 02-May-2022
• ICS: 43.040.10 - Electrical and electronic equipment
• Technical Committee: ISO/TC 22/SC 31 - Data communication
• Drafting Committee: ISO/TC 22/SC 31/WG 4 - Network applications
• Current Stage: 6060 - International Standard published
• Start Date: 03-May-2022
• Due Date: 15-Oct-2021
• Completion Date: 03-May-2022

Relations

• Revises: ISO 16844-3:2004 - Road vehicles — Tachograph systems — Part 3: Motion sensor interface
• Effective Date: 23-Apr-2020

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 16844-3
Second edition
2022-05
Road vehicles — Tachograph
systems —
Part 3:
Motion sensor communication
interface
Véhicules routiers — Systèmes tachygraphes —
Partie 3: Interface de communication pour capteur de mouvement
Reference number
ISO 16844-3:2022(E)
© ISO 2022

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ISO 16844-3:2022(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2022
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
or ISO’s member body in the country of the requester.
ISO copyright office
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Phone: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
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ISO 16844-3:2022(E)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Symbols and abbreviated terms.2
5 Connector . . 4
5.1 Dimensions and pin allocation . 4
5.2 Electrical specification . 4
5.2.1 Electrical requirements . 4
5.2.2 Block diagram data signal, in/out . 5
5.2.3 Voltage monitoring and watchdog signal . 6
5.2.4 Block diagram of the speed signal, real-time . 7
6 Cable . 8
7 Interface protocol . 9
7.1 Transmission . 9
7.1.1 Bit rate and frame structure . 9
7.1.2 Frame specification . 9
7.1.3 State diagram — Communication and execution of instructions . 11
7.2 Motion sensor state at the end of production .12
7.3 Instructions . 12
7.4 Initialisation of communication between motion sensor and recording equipment .13
7.4.1 General .13
7.4.2 Necessary sequence of instruction for pairing .13
7.4.3 Pairing initialisation of recording equipment and motion sensor . 14
7.4.4 Transmission of encrypted serial number of motion sensor . 14
7.4.5 Transmission of session key from recording equipment to motion sensor .15
7.4.6 Transmission of pairing information from recording equipment to motion
sensor . 15
7.4.7 Request from recording equipment for pairing information and
authentication to motion sensor . 16
7.5 Communication of motion sensor and recording equipment in regular use . 16
7.5.1 Sequence of instruction for communication in regular use. 16
7.5.2 Latch of counter value and encrypt data . 17
7.5.3 Transmission of encrypted data . 18
7.6 Read information . 19
7.6.1 Necessary sequence of instruction for reading information . 19
7.6.2 Request . 19
7.6.3 General message structures. 20
7.6.4 Data block chaining . 21
7.6.5 Structures of selected data . 21
7.6.6 Pairing data . 24
8 Optional functionality .25
8.1 Additional direction information in the MF byte . 25
Bibliography .26
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ISO 16844-3:2022(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www.iso.org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to
the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see
www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 22, Road vehicles, Subcommittee SC 31,
Data communication.
This second edition cancels and replaces the first edition (ISO 16844-3:2004), which has been
technically revised. It also incorporates the Technical Corrigendum ISO 16844-3:2004/Cor. 1:2006.
The main changes are as follows:
— part 5 of this series (ISO 16844-5) has been removed due to its technical irrelevance,
— correction of the typos and mistakes in the text,
— adoption of the content according to the new version of the ISO guidelines,
— adoption of the content according to the new technical requirements,
— alignment of the content regarding to the referred standards.
A list of all parts in the ISO 16844 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.
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ISO 16844-3:2022(E)
Introduction
This document supports and facilitates the communication between electronic control units (ECUs)
and a digital tachograph.
The digital tachograph concept is based upon a recording equipment storing data, related to the
activities of the various drivers driving the vehicle, on which it is installed.
During the normal operational status of the recording equipment, data stored in its memory are
accessible to different entities (drivers, authorities, workshops, transport companies) in different ways
(displayed on a screen, printed by a printing device, downloaded to an external device). Access to stored
data is controlled by a smart card inserted in the tachograph.
A typical tachograph system is shown in Figure 1.
Key
1 data and service IF connector standardized in ISO 4 CAN-based data IF including parameter groups
16844-1 standardized in ISO 16844-4
2 electrical data and service IF requirements 5 optional CAN-based service IF standardized in ISO
standardized in ISO 16844-2 16884-6
3 communication interface between motion sensor 6 data identifier (DID) specification for the optional
and RE standardized in this document service IF standardized in ISO 16844-7
Figure 1 — Typical ISO 16844 conformant tachograph system
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INTERNATIONAL STANDARD ISO 16844-3:2022(E)
Road vehicles — Tachograph systems —
Part 3:
Motion sensor communication interface
1 Scope
This document specifies the communication interface between motion sensor and recording equipment.
This includes the mechanical, electrical and logical requirements.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 15170-1, Road vehicles — Four-pole electrical connectors with pins and twist lock — Part 1: Dimensions
and classes of application
ISO 16844-1, Road vehicles — Tachograph systems — Part 1: Recording equipment data and service
connector
ISO/IEC 8859-1, Information technology — 8-bit single-byte coded graphic character sets — Part 1: Latin
alphabet No. 1
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 16844-1 and the following
apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1
check sum
sum (two byte value) of the bytes pointed out at the corresponding location
3.2
direction of movement
bit 6 of byte MF indicating whether the vehicle moving direction is forward or reverse
3.3
direction of movement On
bit 7 of byte MF indicating whether the additional direction information is available or not
3.4
identification key
key necessary for initialisation of a motion sensor, not stored in the sensor memory
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ISO 16844-3:2022(E)
3.5
inter byte timing
possible pause between two bytes of a message
3.6
header
first four bytes of a message containing sync-byte, target, STX and length of the message
3.7
master key
key necessary for initialisation of a motion sensor, not stored in the sensor memory
3.8
pairing key
key only used during the pairing sequence
Note 1 to entry: Every pairing key is unique to the motion sensor to which it belongs. All the cryptography uses
the AES-based encryptions.
3.9
reset
restart of the motion sensor processing unit program
3.10
RxD_in
signal within the motion sensor to the RxD input of the processing unit
3.11
session key
key used for messages to be encrypted
Note 1 to entry: Every session key is unique to a special motion sensor and the recording equipment to which it
belongs.
3.12
tail
last two bytes of a message containing ETX and LRC
3.13
TxD_out
signal within the motion sensor from the TxD output of the processing unit
3.14
voltage monitor
hardware function that detects a drop of the supply voltage below a defined level
4 Symbols and abbreviated terms
For the purposes of this document, the following the following symbols and abbreviated terms apply:
CAN controller area network
CS check sum
CS high byte of CS
high
CS low byte of CS
low
CV control vector
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ISO 16844-3:2022(E)
CVPI check value previous instruction
D data for authentication
A
D data of file selected
Fs
DON direction of movement On
DM direction of movement
D data of sensor (encrypted, i.e. two-key triple DES)
S
eA()
encrypted data A using a particular key K
K
x
x
EXT end of text marker
I current power supply
S
K master key
K identification key
ID
K pairing key
P
K′ key derived from the pairing used to encrypt the pairing data
P
K session key
S
LSB least significant byte
LRC longitudinal redundancy check
MF multi-function byte
MSB most significant byte
NARA new audit record available
n number of bytes
N extended serial number
S
P pairing data
D
R
type approval number of the recording equipment (VU)
type_approval_no
R
serial number of the recording equipment (VU)
serial_no
STX start of text
t
date of pairing
pairing
U speed signal voltage low value
low
U input signal voltage low value
low in
U output signal voltage low value
low out
U speed signal voltage high value
high
U input signal voltage high value
high in
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ISO 16844-3:2022(E)
U output signal voltage high value
high out
U positive supply voltage
pos sply
VU recording equipment
XOR arithmetical exclusive OR
5 Connector
5.1 Dimensions and pin allocation
The connector used (see Figure 2) shall be according to ISO 15170-1, with coding No. 1, application class
2
K3 (contact temperature range −40 °C to +140 °C, maximum acceleration of vibrations 300 m/s ).
The pin allocation shall be in accordance with Table 1.
Key
1 to 4 pin numbers
Figure 2 — Marking zone at fixed or free connector — Code 1
Table 1 — Pin allocation
Pin No. Function
1 Positive supply
2 Battery minus
3 Speed signal, real-time
4 Data signal, in/out
5.2 Electrical specification
5.2.1 Electrical requirements
The allocated connector function shall be in accordance with Table 2 and shall be valid within the
temperature range −40 °C to +135 °C.
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ISO 16844-3:2022(E)
Table 2 — Electrical requirements of allocated connector function
Electrical requirements
Pole
Function Parameter Remark
No.
min. typical. max.
b
1 Positive Voltage 6,5 V — 9 V Reverse voltage protected
supply
Current I — — 15 mA Total unit current without direction signal
S
current, see Clause 8.
2 Battery — — — — See ISO 16844-2.
minus
b
3 Speed signal U — — 0,8 V I = 250 µA
low
a
real-time
b
U U — — I = −150 µA
high pos sply
–1,5 V
Rise time — 50 µs — Test condition: external pull-up resis-
(10 % to 90 %) tor 22 kΩ to positive supply (U );
pos sply
U = 6,5 V; external capacitor 2 nF to
pos sply
Fall time — 10 µs —
battery minus.
(90 % to 10 %)
Frequency — — <1,6 kHz —
b
4 Data signal U — — 1,2 V I = −1 mA
low in
a
in/out
b
U 5,2 V — — I = − 0,5 mA
high in
b
U — — 1 V I = 1 mA
low out
b
U 5,4 V — — I = –20 µA
high out
Rise time — 110 µs — Test condition: external pull-up resis-
(10 % to 90 %) tor 10 kΩ to positive supply (U );
pos sply
U = 6,5 V; external capacitor 5 nF to
pos sply
Fall time — 10 µs —
battery minus.
(90 % to 10 %)
bit rate — 1 200 bit/s — Accuracy ±3 %
a
Outputs shall be short-circuit protected up to 28 V for 1 min.
b
Values are measured relatively to pin 2.
5.2.2 Block diagram data signal, in/out
Figure 3 shows a block diagram of the data interface hardware. If no communication takes place, the
state of pin 4 shall be U . The incoming signal at pin 4 shall be filtered, before it is used as an input
high
signal to the processing unit.
The data TxD_out shall only be transmitted, if the voltage monitor shows that the supply voltage is
within the specified range. See also 7.5.3.1.
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ISO 16844-3:2022(E)
Key
R3 10 kΩ
R4 330 Ω
C3, C4 2,2 nF
V2 npn transistor
Figure 3 — Interface data signal — Example
5.2.3 Voltage monitoring and watchdog signal
5.2.3.1 Electrical requirements
The electrical requirements of the voltage monitoring of supply voltage over pins 1 and 2, and the
watchdog signal, both submitted via pin 4, shall be in accordance with Table 3. If the supply voltage is
below 6,5 V, the motion sensor may reply to requests; but if it is below 5,0 V, it shall not reply.
Table 3 — Requirements of the watchdog signal voltage monitor
Electrical requirements
Parameter Remark
Min. Typical Max.
a
Voltage monitor 5,0 V — U No remark
pos sply
6,5 V
b
Watchdog signal t — — 1 s Sensor watchdog reset delay time
don
t — — 1 s Sensor watchdog recover time
doff
t 1 s — — Watchdog on time
won
t 1 s — — Watchdog off time
woff
a
See block diagram of data signal in Figure 3.
b
Voltage level: see data signal in/out (in) U , see 5.2.3.2.
low in
5.2.3.2 Timing diagram watchdog signal
If the recording equipment discovers a time-out of an expected response, it shall be possible to start
another attempt or send a watchdog signal to the motion sensor in accordance with Figure 4 and, for
voltage levels and timing, in accordance with Table 3. If the motion sensor detects a watchdog signal at
pin 4, it shall restart its program (see 7.5.3.6).
The reset shall not affect the speed real-time signal of pin 3.
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ISO 16844-3:2022(E)
Key
1 normal data signal 4 watchdog detection
2, 3 tachograph sends watchdog signal 5 sensor watchdog recover time
Figure 4 — Timing of watchdog signal
5.2.4 Block diagram of the speed signal, real-time
The speed signal, real-time is a digital signal with a frequency proportional to the rotary speed of the
scanned impulse wheel. Manipulations of this signal shall be of no effect to the messages. Resistance R2
of Figure 5 limits the input current, so it is responsible for overload and short circuit protection.
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ISO 16844-3:2022(E)
Key
R1 4,7 kΩ
R2 1,5 kΩ
C1, C2 1 nF
V1 npn transitor
Figure 5 — Speed signal, real-time — Example
6 Cable
The cable for connecting the motion sensor to the recording equipment shall provide distributed core
capacitances of Cs < 2,0 nF. The cable impedances depend on parasitic capacitances, inductances,
resistances, etc., which influence the transfer characteristic of the cable. The parasitic capacitances
(see Figure 6) are of the greatest influence for the frequency range.
Key
1 – 4 connector motion sensor
B1 – B4 connector vehicle unit
Cs see text
Figure 6 — Equivalent circuit of the cable parasitic capacitances
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ISO 16844-3:2022(E)
7 Interface protocol
7.1 Transmission
7.1.1 Bit rate and frame structure
The transfer of data shall be serial and asynchronous with a bit rate of 1 200 bit per second.
The transmission of one byte shall be according to Figure 7: 1 start bit, 8 data bits, 1 parity bit (even)
and 1 stop bit.
Key
1 don't care
D0 least significant bit
D7 most significant bit
Start bit at low state
Stop bit at high state
Figure 7 — Transmission of one byte
7.1.2 Frame specification
7.1.2.1 Request frame from recording equipment to motion sensor
The request frame from the recording equipment to the motion sensor shall be according to Table 4.
Table 4 — Structure of the request frame
Header Data bytes Tail
a
Sync Target STX Length Instruction Data ETX LRC
number (depend on the instruction number)
a
LRC = XOR from Sync to ETX.
7.1.2.2 Acknowledge frame from motion sensor to recording equipment
The acknowledge from the motion sensor shall be sent as single byte, with the instruction number
appropriate to the recording equipment, if a correct request is detected.
7.1.2.3 Break frame from the recording equipment
If the recording equipment receives an incorrect acknowledge from the motion sensor, the recording
equipment may send a break frame "single byte - value doesn't care".
If the motion sensor detects a break frame, then the scheduled reply shall be aborted, and the motion
sensor shall be ready for a new request. See also 7.1.2.
7.1.2.4 Reply frame from the motion sensor to the recording equipment
The motion sensor shall send the reply frame according to Table 5 if motion sensor data have been
requested from the recording equipment.
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ISO 16844-3:2022(E)
Table 5 — Structure of reply frame
Header Data bytes Tail
a
Sync Target STX Length Data ETX LRC
a
LRC = XOR from Sync to ETX.
7.1.2.5 Sync byte
The sync byte shall be a byte of the value 192 decimal, used for controlling the bit rate.
7.1.2.6 Target byte
The target byte shall identify the direction of transmission, where
— logic “0” identifies transmission direction from the recording equipment to the motion sensor, and
— logic “1” the direction from the motion sensor to the recording equipment.
7.1.2.7 STX byte
The STX byte shall be a constant byte of the value 2 decimal.
7.1.2.8 Length byte
The length byte specifies the length of the complete frame from the sync byte to the LRC; the LRC byte
is included.
7.1.2.9 Data bytes
The data bytes shall contain information interchanged between motion sensor and recording
equipment.
The data bytes shall be sent as MSB first, LSB last.
7.1.2.10 ETX byte
The ETX byte shall be a constant byte of the value 3 decimal.
7.1.2.11 LRC byte
The LRC byte shall be an arithmetical XOR from sync until ETX, including ETX.
7.1.2.12 Timing
During normal operation, the timing parameters shall be those according to Figure 8, which shall be in
accordance with Table 6.
Figure 8 — Structure of timing during normal operation
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ISO 16844-3:2022(E)
Table 6 — Timing values
Value
Timing Description
min. max.
ms ms
P1 0 10 Inter byte timing for the external request
Timing between the external request and the acknowledge from motion sen-
P2 0 25
sor
P3 0 10 Timing in which the break of an acknowledged request is possible
P4 10 30 Timing between the acknowledge and the motion sensor response
P5 0 10 Inter byte timing for the motion sensor response
Timing between the motion sensor responses and start of a new external
a
P6 30 to 25 200 —
request
a
Minimum timing of period P6 depend on the instruction number, as specified in Table 5.
7.1.3 State diagram — Communication and execution of instructions
Figure 9 shows the execution of the programs within the motion sensor and the recording equipment
and how it is affected by the communication.
Figure 9 — State diagram of communication and execution of instructions
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ISO 16844-3:2022(E)
7.2 Motion sensor state at the end of production
The motion sensor shall be prepared for pairing when it leaves the factory, i.e. the following values shall
be stored in its non-volatile memory:
— the extended serial-number of the motion sensor is not encrypted, N , see 7.6.5.6;
S
— the extended serial-number of the motion sensor encrypted with the identification key, e (N )
K S
ID
1)
and all relevant versions of e (N ) ;
K S
ID
1)
— all relevant pairing keys of the motion sensor are not encrypted, K ;
P
1)
— all relevant versions of e (K ), encrypted with the master key of the related version .
K P
The master key and identification key shall not be stored in the non-volatile memory of the motion
sensor. The pairing key shall be unique to each motion sensor. The pairing key is only used to pair the
motion sensor and the recording equipment. A unique session key is generated during the pairing. The
session key is different from the pairing key.
The following information shall also be stored in the non-volatile memory of the motion sensor when it
is shipped:
— motion sensor type is not encrypted;
— date of production of the motion sensor is not encrypted;
— operating system identifier of the motion sensor is not encrypted;
— security identifier of the motion sensor (type of processor used) is not encrypted;
— type approval number of the motion sensor is not encrypted;
— name of the motion sensor manufacturer is not encrypted.
7.3 Instructions
Instruction numbers shall be in accordance with Table 7.
Table 7 — Instruction numbers
Motion sensor Timing
Recording equipment
to next
request
Instruc- Reply
instruction
tion-number
Header Instruction Data Tail Acknowledge Header Instruction Data Tail
ms
bytes bytes bytes bytes bytes bytes bytes bytes bytes
12 600 to
21 000 de-
b a a a a
10 4 1 8 2 1 pending on the
file
d
number
e
11 4 1 0 2 1 4 0 2 30
a
No response to the request except the acknowledge is awaited.
b
The data bytes of the concerned instruction is transmitted encrypted.
c
The data bytes shall not be encrypted.
d
See Table 17.
e
See Table 29 and Table 30.
Key
x motion sensor manufacturer specific
1) For the implementation further specification is needed, which is not in the scope of this document.
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ISO 16844-3:2022(E)
Table 7 (continued)
Motion sensor Timing
Recording equipment
to next
request
Instruc- Reply
instruction
tion-number
Header Instruction Data Tail Acknowledge Header Instruction Data Tail
ms
bytes bytes by
...