ETAS ES1337.2 User manual

ES1337.2 Wheel Speed Sensor Simulation Board
User’s Guide

2
Copyright
The data in this document may not be altered or amended without special
notification from ETAS GmbH. ETAS GmbH undertakes no further obligation
in relation to this document. The software described in it can only be used if
the customer is in possession of a general license agreement or single license.
Using and copying is only allowed in concurrence with the specifications
stipulated in the contract.
Under no circumstances may any part of this document be copied, repro-
duced, transmitted, stored in a retrieval system or translated into another
language without the express written permission of ETAS GmbH.
© Copyright 2018 ETAS GmbH, Stuttgart
The names and designations used in this document are trademarks or brands
belonging to the respective owners.
V1.0.0 R03 EN - 07.2018

Contents 3
Contents
1Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
1.1 Areas of Use and Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
1.2 Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
1.3 Taking the Product Back and Recycling . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
2Hardware Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
2.1 Wheel Speed Sensors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
2.1.1 Type “DF6” . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
2.1.2 Type “DF10” . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
2.1.3 Type “DF10-RotDir” . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
2.1.4 Type “DF11i” . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
2.1.5 Type “VDA”. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
2.2 Analog Outputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
2.2.1 Reference Voltages. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
2.2.2 Type of Output Signal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
2.2.3 Disabling the Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
2.3 Synchronization Signal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
3Pin Assignment and Display Elements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
3.1 Pin Assignment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
3.1.1 “OUTPUT 0-5” Signal Outputs . . . . . . . . . . . . . . . . . . . . . . . . . 21

Contents4
3.1.2 “SYNC” Port . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
3.2 LEDs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
4Technical Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
5ETAS Contact Addresses. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

Introduction 5
1 Introduction
This User’s Guide describes the ES1337.2 Signal Generator Board.
This section contains information on the basic functions and the area of use of
the ES1337.2 Signal Generator Board.
1.1 Areas of Use and Features
The correct determination of the wheel speed by wheel speed sensors is an
important prerequisite for the functioning of lots of ECUs for controlling the
braking force on each individual wheel (ABS, TCS and ESP). The control pre-
vents either the wheels blocking or the wheels spinning in an uncontrolled
manner. Navigation systems also access vehicle speed when the GPS signal is
weak or non-existent.
Wheel speed sensors are available in two basic designs:
• a passive design, in which the sensor element does not require an
external power supply
• an active design with an external power supply of the sensor element
The designs also differ in terms of the physical effect, on which the acquisition
of the wheel speeds is based, and the scope and content of the information
provided by the sensor.
CAUTION!
Some components of the ES1337.2 Signal Generator Board may
be damaged or even destroyed by static discharge. Leave the
board in its transport package until you want to install it.
The ES1337.2 Signal Generator Board should only be taken from
its package, configured and installed at a working place that is
protected against static discharge.
WARNING!
The components, connectors and conductors of the ES1337.2
Signal Generator Board may carry dangerous voltages. These volt-
ages may even exist if the ES1337.2 is not installed in the ES4100
or the ES4105 and the ES4100 or the ES4105 is powered off.
Make sure the ES1337.2 is protected against contact during oper-
ation. Disconnect all connectors to the ES1337.2 before removing
the board.

Introduction6
Features
The ES1337.2 Signal Generator Board has four independent signal generators
for generating various sensor signals. The following types of sensor can be
simulated:
• Passive analog sensors with a sinusoidal output signal (type “DF6”)
• Active digital sensors with a current interface with two current levels
(type “DF10”)
• Active digital sensors with a current interface with three current levels
and forwards/backwards coding (type “DF10-RotDir”)
• Active digital sensors with a current interface with two current levels
and additional information (type “DF11i”)
• Active digital sensors with a current interface with three current levels
and additional information (type “VDA”)
In addition, there are two other galvanically isolated analog voltage outputs.
The ES1337.2 Signal Generator Board has the following features:
• Four identical, galvanically isolated signal generators for generating
speed signals
• Outputs: ±10 V and 0...40 mA with 10-bit resolution
• Two identical, galvanically isolated analog outputs:
– ±10 V with 10-bit resolution
– Configurable reference voltages (internal/external)
• Every channel is protected against overvoltages to ±60 V
• All outputs with a cut-off relay
• Stand still detection (DF11i, VDA) is supported
• Mixed sensor configurations possible
The following figure shows the front panel of the ES1337.2 Signal Generator
Board with
• the LEDs (see "LEDs" on page 23)
• the port for the signal outputs, signal grounds and external reference
voltages (see "“OUTPUT 0-5” Signal Outputs" on page 21).
• the “SYNC” port (see "“SYNC” Port" on page 22) for outputting a
synchronization signal (“tooth 0”), for example to an oscilloscope.

Introduction 7
Fig. 1-1 Front View of the ES1337.2 Signal Generator Board
ES1337.1
ETAS
L0ER L1
SYNC
OUTPUT 0-5

Introduction8
1.2 Block Diagram
Fig. 1-2 shows a block diagram with all important function units of the
ES1337.2 Signal Generator Board.
Fig. 1-2 Block Diagram of the ES1337.2 Signal Generator Board
FPGA Controller
Output 0-5
VMEbus Interface
Output Multiplexer
Analog Outputs Wheel Speed Signal
Generator 0...3
Rotational Speed
Generator
Control Register
SYNC
Output 0...3
Output
Protection
Current
Interface
Output 4...5
Output
Protection

Introduction 9
1.3 Taking the Product Back and Recycling
The European Union has passed a directive called Waste Electrical and Elec-
tronic Equipment, or WEEE for short, to ensure that systems are setup
throughout the EU for the collection, treating and recycling of electronic
waste.
This ensures that the devices are recycled in a resource-saving way represent-
ing no danger to health or the environment.
Fig. 1-3 WEEE Symbol
The WEEE symbol on the product or its packaging shows that the product
must not be disposed of as residual garbage.
The user is obliged to collect the old devices separately and return them to the
WEEE take-back system for recycling.
The WEEE directive concerns all ETAS devices but not external cables or batter-
ies.
For more information on the ETAS GmbH Recycling Program, contact the ETAS
sales and service locations (see "ETAS Contact Addresses" on page 27).

Introduction10

Hardware Features 11
2 Hardware Features
This section contains information on the features of the ES1337.2 Signal Gen-
erator Board.
2.1 Wheel Speed Sensors
This section contains a description of the types of wheel speed sensor that can
be simulated with the ES1337.2 Signal Generator Board.
• "Type “DF6”" on page 12
• "Type “DF10”" on page 13
• "Type “DF10-RotDir”" on page 14
• "Type “DF11i”" on page 15
• "Type “VDA”" on page 17
A basic distinction is made between two processes for recording wheel speeds:
passive and active sensors.
With passive sensors, there is usually an encoder wheel made of ferromagnetic
material which closely runs past a magnet surrounded by a coil. This results in
a constant change of the magnetic flux density which induces a voltage in the
coil.
Active sensors often use an encoder wheel made of alternately opposing mag-
netized segments – the signal is generated in an active circuit by measuring the
magnetoresistance or the Hall effect in a sensor.

Hardware Features12
2.1.1 Type “DF6”
A sensor of type “DF6” is a passive sensor consisting of a magnet wrapped in
a coil in the vicinity of an encoder gear wheel.
The coil and the magnet are mounted on the vehicle or the axle – the move-
ment of the teeth of the encoder wheel along one pole of the permanent
magnet generates an AC signal in the coil which is routed to the correspond-
ing ECU.
The resulting sensor signal approximates the form of a sinusoidal signal (see
Fig. 2-1).
Fig. 2-1 Signal of a Passive “DF6” Sensor
Every tooth generates a period of the sinusoidal oscillations – the signal ampli-
tude depends on the size of the gap between the individual teeth (the air gap)
and the speed. The greater the speed and the smaller the gap, the greater the
induced voltage.
A great disadvantage with this sensor type is the low signal amplitude with low
speeds.
Unfolded Gear
Wheel
Sensor Signal

Hardware Features 13
2.1.2 Type “DF10”
A sensor of type “DF10” is an active sensor in which the signal amplitude is
independent of the speed.
The magnetoresistance is made use of here which leads to the electrical resis-
tance of certain materials changing when they are brought into contact with a
magnetic field. Oscillations of the magnetic flux density correspondingly lead
to fluctuations in the resistance.
In addition to the actual sensor element, magnetoresistance sensors consists of
a permanent magnet and a two-wire connection for the power supply (battery
voltage) and the sensor signal.
This sensor is then positioned on the gear wheel so that there are changes in
the resistance due to changes in the flux density between the tooth and the
gap. The post-connected evaluation unit then returns defined currents of
7 mA (gap) or 14 mA (tooth).
Fig. 2-2 Output Signal of a “DF10” Sensor
The advantage of this principle is that the output signal is not speed-depen-
dent and thus speeds to value 0 can be acquired.
Sensor Signal
Unfolded Gear Wheel
7 mA
14 mA

Hardware Features14
2.1.3 Type “DF10-RotDir”
The sensor of type “DF10-RotDir” differs from “DF10” in that a third current
level is output with reverse movement:
When the vehicle is not moving (speed level < vmin), the current Iidle =7mAis
output. The currents in forward movement and reverse movement are shown
in Fig. 2-3.
Fig. 2-3 Output Signals of a “DF10-RotDir” Sensor
A reverse movement is shown when the sensor outputs a current
Ireverse = 28 mA for a short time treverse.
Iforward
treverse
Iidle
Ireverse
Forward Rotation
Reverse Rotation
Iidle
Ireverse = 28 mA
Iforward = 14 mA
Iidle = 7 mA
Iforward
Gear Wheel

Hardware Features 15
2.1.4 Type “DF11i”
While sensors of types “DF6” and “DF10” only provide the relevant ECU with
information on the wheel speed, sensors of the type “DF11i” (and of type
“VDA”) output pulse-width modulated signals in which additional information
such as direction of rotation and magnetic field strength are coded. These sen-
sors are active sensors whose functioning is based on the Hall effect.
In most cases, the encoder wheel consists of plastic elements (mounted on a
non-magnetic metallic carrier) of opposing magnetization which results in a
sign change of the Hall voltage on rotation.
It is, however, also possible for the encoder wheel to be made of a ferromag-
netic material – in this case, the Hall element is positioned on a permanent
magnet. The change between tooth and gap of the encoder wheel leads to a
change of the magnetic flux density and thus to fluctuations in the Hall volt-
age.
The signals ultimately provided by the sensor consist of current pulses of
14 mA (low = 7 mA) whose frequency is proportional to the speed and whose
rising edges have a precise temporal relationship to the change of the seg-
ments.
The pulse width is determined by the direction of rotation and the field
strength: It consists of multiples of a well-defined time interval.
When the encoder wheel is paused or there is no change to the sensor signal
for another reason, a standstill pulse with approx. 1.5 Hz repetition rate is out-
put.
Fig. 2-4 on page 16 shows the various output signals of a “DF11i” sensor:
• A high-level pulse is output when there is a segment change at the
encoder wheel. This pulse is preceded by a short low-phase T0typically
45 μs long – this phase is referred to as the pre-bit phase.
• A large gap results in a low magnetic field strength. This is indicated by
a high pulse of width T0(air gap limit1). This signal is output for both
directions of rotation.
• Normal field strengths are shown by pulse widths of 2 T0(reverse direc-
tion of rotation) or 4 T0(forward direction of rotation).
• The field strength range above the air gap limit is referred to as the
mounting position error range. In this range, a pulse of length 8 T0
(reverse direction of rotation) or 16 T0(forward direction of rotation) is
output.
1. The air gap limit specifies whether the magnetic field strength change is
below a value necessary for perfect functioning.

Hardware Features16
• If there is no field available or if the wheel stands still for more than
737 ms, a high pulse of width 32 T0is output every 737 ms.
Fig. 2-4 Output Signals of a “DF11i” Sensor
Very low field strength
(Air gap limit error)
Backward drive
normal field strength
Forward drive
normal field strength
Backward drive
low field strength
(mounting position error)
Forward drive
low field strength
(mounting position error)
T0
2T0
4T0
8T0
16T0
32T0
737 ms
T0 = 45 µs
No field or vehicle
stopped for > 737 ms
No Field or Vehicle Stopped
7 mA
14 mA
7 mA
14 mA
Vehicle Movement
7 mA
14 mA
7 mA
14 mA
7 mA
14 mA
7 mA
14 mA
N S

Hardware Features 17
2.1.5 Type “VDA”
“VDA” sensors are also active sensors and, like the “DF11i” sensors, are based
on the Hall effect.
The following figure shows the output signal of this sensor.
Fig. 2-5 Speed Pulse and Data Bits
The speed pulse is output at every “edge” of the encoder wheel – the current
IHof this pulse is four times the low level IL=7mA.
An initial bit that sets the current level to ILprecedes this pulse. A further nine
bits follow the speed pulse with a current level of IH=2I
L.
IL = 7 mA
IM = 2 IL
IH = 4 IL
0231 45678
Data Protocol Bits
Speed Pulse
Initial Bit
N S

Hardware Features18
The meaning of these bits is described in the following table.
Tab. 2-1 Meaning of the Nine Protocol Bits
Bit Number Meaning Coding
0 Error bit air gap limit 0 = correct
1 = air gap limit
1Can be assigned freely
2 Can be assigned freely
3Validity of direction of rota-
tion
0 = valid
1 = invalid
4 Direction of rotation 0 = positive
1 = negative
5Can be assigned freely
6 Can be assigned freely
7Can be assigned freely
8 Parity bit Is set to 0 or 1 to retain even
parity (incl. the parity bit itself).

Hardware Features 19
2.2 Analog Outputs
Each of the two analog voltage outputs of the ES1337.2 Signal Generator
Board can be configured so that
• the internal reference voltage or one applied from outside is used
• an analog signal or a digital signal derived from the output voltage is
output
• an output configured as digital is used as an open collector output or
as an open collector output with pull-up functionality
• the output is completely powered off
2.2.1 Reference Voltages
The internal reference voltage (= 10 V) or a voltage applied to the external
reference voltage input of the channel between -10.0 V and 10.0 V (see
"“OUTPUT 0-5” Signal Outputs" on page 21) are available.
The actual output voltage of the relevant channel is the product of the refer-
ence voltage and the control signal (with an analog configuration).
The reference voltage is selected in the “Globals” tab of the ES1337-Wheelsn-
srsim-DA Device (“Analog Reference Output #4, #5” option) in LABCAR-RTC.
2.2.2 Type of Output Signal
The digital signal is derived from the analog signal – the comparator threshold
corresponds to 1 V when using the internal reference or 0.1 x Vext when using
the external reference.
Selection takes place in the “Globals” tab of the ES1337-Wheelsnsrsim-DA
Device (“Configuration Output #4, #5” option) in LABCAR-RTC.
2.2.3 Disabling the Output
An analog channel is disabled in the “Signals” tab of the ES1337-Wheelsnsr-
sim-DA Device (“Enable_4” and “Enable_5” option) in LABCAR-RTC. The
channel output is high-impedance when disabled.
2.3 Synchronization Signal
To synchronize with external devices (e.g. an oscilloscope), one of the four
wheel speed sensors can output a “tooth 0-pulse” as a TTL signal at the
“SNYC” port.
The sensor this signal comes from is selected in LABCAR-RTC in the “Globals”
tab of the ES1337-Wheelsnsrsim Subsystem (“SYNC Port” option).

Hardware Features20