Hardware
English, Revision 06, Date: 12.07.2011
17
3.6
Operation with serial interface (RS 232) interface
In this control mode the input information will be transmitted as serial sequence. The
output information will also be transmitted over 10 byte telegram.
3.7
Operation with digital/analog interface
In order to operate the Optical Line Tracker using this interface unit, the following con-
nections have to be made:
-
In case an operation without turn offs is planned, it is necessary to parallel the
inputs
IN1
and
IN2
. The analog output for the track deviation is deactivated
whenever
IN1
and
IN2
are either not connected or inactive.
-
Whenever only one camera is used, the input
IN3
(camera selection) may either
remain blank or may be connected to ground. In this case, the camera must be
connected to
IN1
.
-
Output OUT8 is activated as soon as the covariance maximum exceeds the set
threshold (refer to menu
Image Settings
in section 4.3 on page 24 in chapter
Setting Parameters
). The value of the voltage at the analog output indicates
the location of the guidance track within view (the lateral deviation from the center
of the field of vision).
-
In case the track quality (value of the covariance maximum) decreases below a
set threshold, output
OUT7
is activated. In such a case, the vehicle could, for
example, drive slower in order to securely get through an area of bad tracking
quality.
-
For higher security reasons, output
OUT6
has been created: once the device has
been switched on it becomes inactive if it is detected that the EEProm’s set of
parameters is faulty. In addition, it becomes inactive in case an activated output
(
OUT1
-
OUT8
) is short-circuited. In the latter case, a check is carried out every
500 ms, investigating whether the short-circuit is still there. If not, the correspond-
ing output will be re-activated. During this examination, which takes 20 ms,
OUT6
is activated.
-
Furthermore, 2 independent symmetrical deviation threshold can be put out:
In case the deviation from the track is greater than the value set for threshold 1,
OUT1
activated. If the deviation from the track is less than the negative value of
threshold 1,
OUT3
is activated.
In case the deviation from the track is greater then the value set for threshold 2,
OUT2
is activated. If the deviation from the track is less than the negative value of
threshold 2,
OUT4
is activated.
The values for thresholds 1 and 2 may be changed in menu
Output-Input
Settings
. These outputs may also be used for controlling the velocity of the
vehicle.
-
It is possible to set certain parameters related to the behaviour of the analog out-
put in case the track ends or cannot be read anymore:
Either value 0 V (or the voltage value corresponding to the offset value) is put out
or the old value is maintained.
