Installation / Commissioning
English, Revision 06, Date: 14.12.2016
10
Whenever a transponder is crossed, initially the sum voltage will increase. Once the
Threshold for Decoding
has been reached, the bit
TRANS_IN_FIELD
is being
set. It takes 4 x 8 ms (= 4 datapoints) for the transponder code to be decoded. The
duration depends on the setting of
Number of Equal Codes
in menu
Time &
Code
. In the given example, the value is = 2, i. e. the received code is compared to
two pre-ceding codes.
When crossing the center of the antenna, the
POSI-Pulse
is generated. The duration
of the
POSI-Puls
is adjustable. The bits
TRANS_IN_FIELD
and
CODE_OK
are delet-
ed as soon as the sum voltage falls below the set value for
Threshold for Deco-
ding
. In the given example, there was an additional period of 6 x 8 ms for the gener-
ation of the
POSI-Pulse
. The transponder crossing speed was approx. 1,9 m/s (300
mm length of active antenna area / (20 x 8 ms)).
The following diagrams illustrate the effects of high interference levels.
Figure 5
Diagram: Commissioning protocol / high interference level; shown is the
sum voltage over the distance travelled, indicated by different transponder
codes
The interference level reaches up to 300 samples. At transponder 207, the noise
reaches a level that even directly influences the transponder signal. As a result, it takes
9 x 8 ms until the transponder 203 has been decoded (refer to Figure 6 on page 11).
For the slow crossing speed of 1.1 m/s (300 mm / (33 x 8 ms)) 9 x 8 ms is still sufficient
for generating a
POSI Pulse
, but at a speed of 3 m/s it would no longer be possible
to decode this transponder.
High interference
