bf1systems BF1IRV3WE User Manual

bf1systems IRTPTMS V3 System Description

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Date

Modifications

Author

Version

Modified

Sheets

Approved

By

Date

Signed

04/11/2013

Document creation

SG

1_01

All

GMS

05/11/2013

GMS

bf1systems IRTPTMS V3 System Description

1 Modifications

If this document has been printed then it cannot be guaranteed that it is the most recent version. Please refer to the
document directory for the latest release.

The information in this document is the property of bf1systems and may not be copied, communicated to a third party or
used for any purpose other than for which it is supplied without the express written permission of bf1systems.

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2 Table of Contents

1 Modifications ......................................................................................................................................................................... 1

2 Table of Contents .................................................................................................................................................................. 2

3 Table of Figures ..................................................................................................................................................................... 3

4 Conformity to FCC-Rules ....................................................................................................................................................... 4

4.1 United States of America .............................................................................................................................................. 4

4.1.1 Statement FCC 15.19: Labelling requirements .................................................................................................... 4

4.1.2 Statement FCC 15.21: Information to the user ................................................................................................... 4

5 System and Functional Description ...................................................................................................................................... 5

5.1 System Description ....................................................................................................................................................... 5

5.2 Functional Description .................................................................................................................................................. 6

6 Warning Algorithm ................................................................................................................................................................ 6

6.1 Warning Limit “Minimum pressure” ............................................................................................................................ 6

6.2 Warning Limit “Nominal pressure minus relative deviation” (Nominal Pressure – 25%) ......................................... 6

7 System Components ............................................................................................................................................................. 7

7.1 Motorsport DigiTyre ECU (MDE) .................................................................................................................................. 7

7.1.1 Installation Area .................................................................................................................................................... 7

7.1.2 Temperature Range .............................................................................................................................................. 7

7.1.3 Voltage Range ........................................................................................................................................................ 7

7.1.4 Current Consumption ........................................................................................................................................... 7

7.1.5 MDE Pin Description ............................................................................................................................................. 7

7.1.6 CAN Bus Connection ............................................................................................................................................. 8

7.2 Wheel Electronics .......................................................................................................................................................... 8

7.2.1 Installation Area .................................................................................................................................................... 8

7.2.2 Versions ................................................................................................................................................................. 8

7.2.3 Temperature .......................................................................................................................................................... 8

7.2.4 Pressure ................................................................................................................................................................. 9

7.2.5 Environmental Requirements .............................................................................................................................. 9

7.2.6 Mechanical specification ...................................................................................................................................... 9

7.2.7 Measurement specification .................................................................................................................................. 9

7.2.8 Byte format ......................................................................................................................................................... 10

7.2.9 Specification for HF transmitter ........................................................................................................................ 10

7.2.9.1 Frequency ....................................................................................................................................................... 10

7.2.10 Transmission ....................................................................................................................................................... 11

7.2.11 Block diagram wheel electronics ....................................................................................................................... 11

7.3 Digital antenna ........................................................................................................................................................... 11

7.3.1 Installation area .................................................................................................................................................. 11

7.3.2 General dimensions and values ......................................................................................................................... 11

7.3.3 Temperature ranges .......................................................................................................................................... 11

7.3.4 Voltage supply .................................................................................................................................................... 11

7.3.5 Current consumption ......................................................................................................................................... 11

7.3.6 Environmental conditions .................................................................................................................................. 12

7.3.7 LIN communication with MDE/Combined Antenna ECU control unit ............................................................ 12

7.3.8 Connection occupancy, sleeve strip .................................................................................................................. 12

7.3.9 Block diagram ..................................................................................................................................................... 12

7.3.10 Assembly ............................................................................................................................................................. 12

7.4 Trigger transmitters ................................................................................................................................................... 13

7.4.1 Temperature ....................................................................................................................................................... 13

7.4.2 Mechanical requirements .................................................................................................................................. 13

7.4.3 Voltage range ..................................................................................................................................................... 13

7.4.4 Current consumption ......................................................................................................................................... 13

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7.4.5 Frequency ........................................................................................................................................................... 14

7.4.6 Modulation ......................................................................................................................................................... 14

7.4.7 Physical link ......................................................................................................................................................... 14

7.4.8 Protocol ............................................................................................................................................................... 14

7.4.9 Diagnostics .......................................................................................................................................................... 14

7.4.10 Connector ........................................................................................................................................................... 14

7.4.11 Environmental qualification .............................................................................................................................. 14

7.4.12 Schematic representation of the trigger transmitters ..................................................................................... 14

3 Table of Figures

Figure 2: Wheel electronics block diagram .............................................................................................................................. 11

Figure 3: Antenna pinout ........................................................................................................................................................... 12

Figure 4: RF Antenna structure ................................................................................................................................................. 12

Figure 5: RF Antenna dimentions .............................................................................................................................................. 13

Figure 6: LF Satellite Trigger ....................................................................................................................................................... 15

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4 Conformity to FCC-Rules

Electronic wheel sensors within the IRTPTMS system contains Transmitter Module FCC ID: xxx-xxxxxxxxx

4.1 United States of America

4.1.1 Statement FCC 15.19: Labelling requirements

This device complies with Part 15 of the FCC Rules.
Operation is subject to the following two conditions:

(1) This device may not cause harmful interference, and
(2) This device must accept any interference received, including interference that may cause undesired

operation.

4.1.2 Statement FCC 15.21: Information to the user

The user manual or instruction manual for an intentional or unintentional radiator shall caution the user that changes or
modifications not expressly approved by the party responsible for compliance could void the user’s authority to operate
the equipment.

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5 System and Functional Description

5.1 System Description

The Infrared Tyre Pressure & Temperature Monitoring System (IRTPTMS) monitors vehicle tyre pressures and
temperatures.

A typical system is comprised of the following components:

 1 Motorsport DigiTyre ECU (MDE)
 Up to 4 wheel electronics including mounting system
 Up to 4 digital antennas
 Up to 4 trigger transmitters

The wheel electronic mounted on the wheel rim measures tyre pressure ambient temperature and tyre carcass
temperature at regular intervals and transfers the values wirelessly to the reception antenna(s). The current pressure
and temperature values can be requested specifically via the LF trigger function. In the digital antenna, the radio data
telegram is decoded and transferred to the ECU unit as a digital signal. The ECU unit evaluates the received data and
forwards the information as required.

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5.2 Functional Description

The wheel electronic is mounted on the wheel rim and measures tyre pressure, temperature and wheel electronic
status. The measured data is sent from the wheel via a transmit stage in the wheel electronics. A system with relatively
seldom-measured data transfer is adequate for tyre pressure monitoring, provided it features the additional option of
detecting sudden pressure loss. This enables the electronics in the wheel to be designed for minimal power draw and
thus maximize battery life.

All wheel electronics have a unique ID code that is forwarded along with data at each transfer. The HF transfer occurs in
the 433MHz range, referred to as the ISM range. The trigger functionality is achieved by the use of a 125 kHz LF channel.

The control unit calls up the wheel electronics via the trigger transmitters when power is supplied to the MDE. When a
pressure loss > 0.2 bar on the previously measured pressure value is detected, the wheel electronics switch immediately
to fast-transmit mode. In this situation, the wheel electronics measure and transmit every 0.8 seconds.

The IRTPTMS measures and transfers considerably more data than is necessary to ensure reliable basic function. It can
therefore use a data transfer path this is not assigned for the error-free transfer of each individual data protocol. Using
the trigger function, an implausible and/or non-received data message can be requested again from the corresponding
wheel electronics.

The data sent by the wheel electronics is received via the digital antenna and is subsequently decoded. The decoded
data is transferred onwards to the MDE unit via a digital interface (LIN interface). The MDE unit evaluates the received
data and forwards the information to the driver information system as required. This provides the driver with
information on the necessary tyre pressure or temperature.

The main functional characteristics of the control unit are:

 A central warning algorithm and an algorithm for the wheel manager.
 The vehicle-specific connection for the power supply system and manufacturer-specific operation and display

philosophy.

6 Warning Algorithm

The system monitors a nominal pressure, which is set automatically when the tyre speed exceeds 30kph, and a fixed set
minimum warning pressure. The higher value in each case is used to generate the deflation warning.

6.1 Warning Limit “Minimum pressure”

At this warning limit, a check is made against the minimum warning pressure Abs
into the system as a fixed value.

The corresponding warning bit is set, if the measured pressure lies below this threshold twice in succession.

6.2 Warning Limit “Nominal pressure minus relative deviation” (Nominal Pressure – 25%)

This warning limit is calculated from the nominal pressure less a relative deviation of 25% of the nominal pressure. The
nominal pressure is specified by the driver. An accuracy reserve of 0.1 Bar is added to the warning limit.

The corresponding warning bit is set if the measured pressure lies below this threshold twice in succession.

Minimum, which is programmed

Pressure

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System Connection (8STA2-10-35PN, Male, Circular)

Pin

Description

Pin

Description

1

Protected Ignition, +12 V

8

CAN L (DASH), BLUE

2

GND, LIN GND, RS232 GND

9

RS232 DATA TX / Configure Input A

3

LIN V RL TRIGGER Switched

10

RS232 DATA RX / Configure Input B

4

LINV TRIG FR/RR ANT FRT/REAR

11

LIN DATA RL TRIG/FRT ANT

5

LIN V FL TRIGGER Switched

12

LIN DATA FL TRIG/REAR ANT

6

LIN DATA FR TRIGGER

13

LIN DATA RR TRIGGER

7

CAN H (DASH), RED

7 System Components

The system components of the IRTPTMS are described in the following sections.

7.1 Motorsport DigiTyre ECU (MDE)

The MDE control unit consists of a printed circuit board with a microcontroller and interfaces for CAN, RS232 and TPMS­LIN.

The tyre information received from the digital antennae is recorded and evaluated in the control unit. The pressure
information and, if applicable, the warning information, is forwarded via the CAN bus to the display systems in the
vehicle.

The information from the digital antennae is transferred to the control unit via a LIN bus communication link. The
control unit is the master here, while the antennae and/or the trigger transmitters work as slaves. The control unit
interrogates the digital antennae at set intervals with respect to radio messages. The trigger transmitters are contacted
in sequence. The control unit also provides the supply voltage to the trigger transmitters and the antennae. The most
important details of the control unit are described below.

7.1.1 Installation Area

The control unit is intended to be installed in the interior of the vehicle. If not stated otherwise, the values stated in the
following chapters relate to a temperature of 25°C and to the current sample control units based on the HCS12
processor.

7.1.2 Temperature Range

Operating temperature: -40°C to +80°C
Storage temperature: -40°C to +85°C

7.1.3 Voltage Range

Nominal voltage: 12V
Operating voltage: 9V to 16V
Maximum voltage: 0 to +18V, with polar protection
Under voltage switch off: The control unit is switched off when V
No. of Antennas / triggers that can be supplied: 6

7.1.4 Current Consumption

Normal operation: < 200 mA @ 12V (without antennae or trigger)

7.1.5 MDE Pin Description

< 7.5V

batt

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Secondary Connection (8STA2-10-35SA, Female, Circular)

Pin

Description

Pin

Description

1

Configure Input C

8

N/C

2

Configure Input A / RS232 DATA TX

9

N/C

3

Configure Input B / RS232 DATA RX

10

N/C

4

Daughterboard Out 2

11

N/C

5

GND Sense

12

N/C

6

RS232 GND

13

N/C

7

N/C

Min

Max

Units

Working temperature

0

+125

°C

Storage temperature > 50°C max. 30 days

+50

+70

°C

Storage temperature (6 months)

0

+50

°C

Temperature gradient in the working temperature range

-16

+16

K/s

7.1.6 CAN Bus Connection

Vehicle bus: High speed CAN, transfer rate 1Mbits/sec
TPMS bus messages: Programmable to customer requirements
Start-up behaviour: Power applied to the MDE

CAN interface data:
Driver module: TJA1050T
CAN H / CAN L – line: Resistant to short circuits against GND and +V

batt

7.2 Wheel Electronics

The wheel electronics measure the pressure, the air temperature inside the tyre, plus the tyre carcass temperature and
transmit this data via a HF radio route, together with its residual battery life and ID code to the digital antenna.

7.2.1 Installation Area

The wheel electronics are mounted on the inside of the wheel rim.
During assembly, the bf1systems assembly guidelines must be noted.

7.2.2 Versions

The working frequency of 433MHz is used exclusively.

7.2.3 Temperature

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Pressure overload

Maximum 2000 kPa

Measurement range

50 kPa to 732.5 kPa

Vibration with overlying temperature

Temperature profile

0°C to 125°C

Vibration profile 1

20Hz to 2000Hz: 2 g2/Hz to 0.035 g2/Hz

Acceleration

Static acceleration (vertical to PCB)

12 x half sine shock pulses of 80g pk acceleration,
pulse width 6ms

Evaluation criteria

No malfunction during and after the test

7.2.6 Mechanical specification

Dimension

70.1mm x 33.4 x 26.8mm

Wheel Sensor Assembly Weight

45g ±1g

7.2.7 Measurement specification

Pressure

Comment

Min

Nom

Max

Units

Measurement range

Nominal

0.882

-

4.631

bar

Accuracy

0°C to +50°C

-29.4

-

+29.4

mbar

Resolution

LSB

-

14.7

-

mbar

Pressure Sensor
Temperature

Comment

Min

Nom

Max

Units

Measurement range

-

-40

-

215

°C

Accuracy

0°C to +50°C

-1

-

+1

°C

Resolution

LSB

-

1

-

°C

IR Sensor Temperature

Comment

Min

Nom

Max

Units

Measurement range

-

-2

-

125

°C

Accuracy

-

-0.5

-

0.5

°C

Resolution

LSB

-

0.125

-

°C

7.2.4 Pressure

7.2.5 Environmental Requirements

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Tyre Carcass Surface Temperature (±17.5° & ±45° Field of view)

Comment

Min

Nom

Max

Units

Measurement Range

-

-40 - 215

°C

Resolution

10-bit - 0.25 - °C

Accuracy
(Under isothermal
conditions)

Ambient temp of 0 - 50°C and target temp of
0 - 60°C

-

±0.5 - °C

Ambient temp of 0 - 50°C and target temp of
61 – 180°C

-

±2 - °C

Ambient temp of 0 - 50°C and target temp of
181 – 215°C

-

±3 - °C

Ambient temp of 0 - 100°C and target temp
of 0 – 120°C

-

±1 - °C

Ambient temp of 0 - 125°C and target temp
of 0 – 180°C

-

±2 - °C

Ambient temp of 0 - 125°C and target temp
of 181 - 215°C

-

±3 - °C

Acceleration

Comment

Min

Nom

Max

Units

Recognition threshold
for turning wheel
(RS == 1)

-40°C to +90°C

2

11

20

g

> 90°C 2 14

26

g

Recognition threshold for
resting wheel (RS == 0)

-40°C to +90°C

1

10

19

g

> 90°C 1 13

25

g

Start bit

None

Data bits

8, MSB first

Stop bit

None

Code specification

Conditioned diphase code

Description

 flank at the start of a bit interval
 no flank in the middle of a "1" interval
 flank in the middle of a "0" interval

Data format

Binary

Transmission rate

9.6 kbps +/- 10%

7.2.9 Specification for HF transmitter

7.2.9.1 Frequency

433 MHz Version

Modulation

Frequency shift keying (2-FSK)

Frequency f

nom

@ 25°C

433.920 MHz  35 kHz

Frequency drift overall (aging, temperature)

f

nom

 85 kHz

Logic levels
Data = 0

f

nom

- f/2

Data = 1

f

nom

+ f/2

7.2.8 Byte format

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7.2.10 Transmission

Marking for type approval

433 MHz Version

Tolerance transmitted power

+/- 3 dB @ 25°C

Tolerance transmitted power over lifetime

- 3 dB

Tolerance transmitted power over working
temperature range

- 5 dB

7.2.11 Block diagram wheel electronics

Figure 1: Wheel electronics block diagram

7.3 Digital antenna

The digital antenna has integrated signal conditioning (decoding processor) to receive and decode the HF signal sent by
the wheel electronics. The conditioned information is transferred to the MDE control unit via a LIN communication.

7.3.1 Installation area

The digital antennae are mounted on the outside of the vehicle. The area directly subject to being hit by stones from the
road must be avoided. The antennae should therefore be installed in a protected position behind a plastic trim (wheel
housing shell, or similar).

7.3.2 General dimensions and values

Dimensions: See Chapter on “Assembly”
Frequency range of the receiver: 550kHz @ -85dBm / 20°C
Type of modulations: FSK, hard keyed
Sensitivity within bandwidth @ 25°C >5nT <8nT
Reduction of Sensitivity over frequency max. 1nT
Reduction of Sensitivity over temp max. 1nT
Reception to wake-up: 5 dB +/-1dB
RSSI signal: Start of climb typically 16dBµV @ 25°C
Saturation typically 56dBµV @ 25°C
Radio data rate: 9.6kBaud +/- 10%
Radio reception frequency: 433.92 MHz +/-200kHz

7.3.3 Temperature ranges

Operating temperature: 0°C to + 125°C
Storage temperature: 0°C to + 70°C

7.3.4 Voltage supply

Supply line: Two wire circuit, V
for each digital antenna
Supply voltage: > (V

batt

– 2V)

Switch type: High side switch

7.3.5 Current consumption

Supply current, digital antenna: At HF reception < 30mA permanently

batt

, GND

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Pin:

Signal:

Description:

1

LIN_GND

LIN Ground

2

LIN_V1

LIN Supply voltage

3

LIN_DATA

LIN Data

4

SCREEN_GND

Ground for Screen Connection (optional)

7.3.6 Environmental conditions

Protection class: IP 69K in line with test according to DIN 40050
Salt spray: 144h in line with test according to DIN 50021-SS
Pressure balance: Climate membrane 2 mm 

7.3.7 LIN communication with MDE/Combined Antenna ECU control unit

The LIN communication of the antennas with the MDE/Combined Antenna ECU control unit fulfils the specification of
the LIN Consortium Version 1.1. The MDE control unit is in master operation here, while the antennas are in the slave
condition.
The following details apply:
LIN bit rate: 10k Baud +/-2%
LIN driver: Infineon TLE 6259-2G
Bus coupling: EMC network
Signal reference: Ground

7.3.8 Connection occupancy, sleeve strip

Manufacturer: Tyco electronics AMP GmbH
Type, plug connector: MQS in line with Tyco drawing 114-18063-014
Contact system: Micro-Quad-Lock
Version: Pin shell
Number, contact pins: 4 Pins
Pin version: Sealed, gold-plated
(sealed; selectively gold-plated),
Sealing system: Primary sealing: Lamellar sealing in the housing
Secondary sealing: Individual seam sealing
Distance between pins (Pitch): 2.54x2.54mm

Figure 2: Antenna pinout

7.3.9 Block diagram

The basic electrical structure of the antenna electronics is outlined below.

Figure 3: RF Antenna structure

7.3.10 Assembly

The digital antenna can be mounted in the vehicle in line with the following sketch.

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7.4.1 Temperature

Operating temperature

-40°C to +105°C

Storage temperature

-40°C to + 90°C

7.4.2 Mechanical requirements

Dimensions

90.5mm x 65.0mm x 27mm

4 vibration loading capacity

3533 41 202 001 C

Shock loading capacity

3533 41 202 001 C

Free fall

1000 mm falling height, concrete (EN 60068-2-32)

Plug push thru strength

> 55N

Soundness

IP 69K

Pressure balance

Climate membrane 2 mm 

7.4.3 Voltage range

Static voltage strength

+20V / -2.8V limited by control unit

Dynamic voltage strength

Interference pulses Type 3a, 3b via coupling clamp

ESD strength

8 kV (human body model)

Operating voltage

+7.0V to +18V

7.4.4 Current consumption

Passive operating current

< 10 mA @ 12V

Active operating current (transmitting)

< 230 mA @ 12V

7.4 Trigger transmitters

Figure 4: RF Antenna dimentions

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Ground current

< 230 mA @ 12V

7.4.5 Frequency

Frequency

125 kHz +/-5 kHz @ -40°C to +105°C
(In condition installed in vehicle)

Field strength

< 21 dBV/m @ 3m, 16V

Duration of transmission

< 10 s

Keying ratio

< 0.1

Field orientation

Field of a magnetic dipole, symmetrical axis transverse to the
housing

7.4.6 Modulation

Modulation

Duration of impulse

Baud rate

< 0.5 kBaud

Report

See specification for the corresponding WE

7.4.7 Physical link

Data interface

LIN specification Rev. 1.1

7.4.8 Protocol

Data report

LIN specification Rev. 1.1
LIN_SPDPS.doc
LIN_Master.doc
LIN_Slave.doc

7.4.9 Diagnostics

Current monitor in the antenna circuit

VM > 0.5 V (in the transmission impulse)

Diagnostics response

Set diagnostics status (see LIN_Slave.doc)

7.4.10 Connector

Type

Mini-timer, 4-pole

Pin 1

LIN_GND

Pin 2

LIN_V1 (Voltage supply)

Pin 3

LIN_DATA

Pin 4

SCREEN_GND

7.4.11 Environmental qualification

3533 41 202 001 C

7.4.12 Schematic representation of the trigger transmitters

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Figure 5: LF Satellite Trigger