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
I
H
of this pulse is four times the low level I
L
= 7 mA.
An initial bit that sets the current level to I
L
precedes this pulse. A further nine
bits follow the speed pulse with a current level of I
H
= 2 I
L
.
I
L
= 7 mA
I
M
= 2 I
L
I
H
= 4 I
L
0
2
3
1
4
5
6
7
8
Data Protocol Bits
Speed Pulse
Initial Bit
N
S
Summary of Contents for ES1337.2
Page 1: ...ES1337 2 Wheel Speed Sensor Simulation Board User s Guide ...
Page 10: ...Introduction 10 ...
Page 20: ...Hardware Features 20 ...
Page 24: ...Pin Assignment and Display Elements 24 ...
Page 26: ...Technical Data 26 ...
Page 28: ...ETAS Contact Addresses 28 ...
