User Manual

Bosch Rexroth AG 7/12
RE 95132/11.08
DSM Series 10
Output signals
Performance during standstill
Sensor signal after no speed signal was detected within one second:
Sensor-internal speed signal
Transmitted signal
Standstill pulse = 32 x LR
t = 0.7 s
Description
When the vehicle is stationary, pulses 1.44 ms in length are emitted every 0.7 seconds by the sensor. These pulses are also
output after undervoltage if no speed signal is detected.
In the standstill, an initialization is also performed. This initialization lasts between 255 and 345 µs. During this time, no signal
change can be detected.
Signal tolerances
From the tolerances of the internal components in the sensor,
the following periods (minimum, nominal, maximum) are deter-
mined for the individual cases:
Pulse designation
Pulse width t
pulse
min
typi-
cal
max
Prebit (low) t
Prebit
37 45 53 µs
Air-gap reserve
LR
t
LR
37 45 53 µs
Counter-clockwise rotation
DR-L
t
DR-L
74 90 106 µs
Clockwise rotation
DR-R
t
DR-R
149 180 211 µs
Counter-clockwise rotation
and EL
DR-L/EL
1)
t
DR-L/EL
298 360 422 µs
Clockwise rotation and EL
DR-R/EL
1)
t
DR-R/EL
597 720 843 µs
Standstill
STOP
t
Pulse
stop
1194 1440 1685 µs
Standstill recognition t
Stop
611 737 863 ms
1)
The pulse DR-L/EL or DR-R/EL is output only up to a signal
frequency of approx. 117 Hz. Above this frequency, this pulse
is then released via the shorter DR-L or DR.R
Signal when departing from a standstill or during
startup
When the output values (frequency, direction of rotation, …)
are being determined, a certain number of pulses are needed
so that the supplied information can only be ensured after a
certain number of pulses.
When starting out from a standstill or after the undervoltage
state, the sensor is first set in an uncalibrated state (signal not
offset-compensated). Also during this phase, the sensor sup-
plies a correct frequency signal at the beginning of the second
signal pulse and under typical conditions also supplies a cor-
rect direction of rotation signal as of the third signal pulse. In
this mode, the minima and maxima of the magnetic input signal
are used as trigger points.
During the output of the signal in the uncalibrated mode, a
calibration (offset calibration) of the signal is performed by
the sensor. The sensor then automatically switches into the
calibrated mode. From that point on, the zero crossings of
the magnetic input signals are used as trigger points. When
switching over into the calibrated mode, a phase shift of the
output signal can occur in infrequent cases (maximum -90 °
or +90 °).
The number of Signal pulses output in uncalibrated mode is no
more than five.