DCT e-track, Руководство пользователя

Страница: 82 / 212

4.9. THE TIME AND DISTANCE CRITERIA
The Minimum time between reports takes control of the report when
the unit exceeds the Distance threshold . Assuring that even when
the unit is exceeding the Distance threshold it will not report too fre-
quently, no more frequent than the configured minimum time value.
One way of seeing this parameter is that this time will be the report
period when the unit is traveling too fast.
A
Time and Distance signal is configured with the following param-
eters:
1. Distance Threshold.
2. Minimum time between reports.
3. Maximum time between reports.
A T&D signal (
TD
) gets high according to its defined T&D parame-
ters and it is immediately reset after all events have been evaluated
in order to get ready for the activation of the signal again, when the
T&D criteria is met on the future.
To create a tracking event that sends event code 49 based on a T&D Example
criterion. A 8km ( 5miles )report is desired. The criterion must be so
that no more than one hour passes between successive reports, and
the minimum time between successive reports must be 2 minutes.
To do so we choose for no particular reason the T&D criterion
6
.
The requirements call for the following T&D configuration:
• Minimum time between reports: 120 seconds (2mins).
•
Distance Threshold: 80 x 100m (8km).
• Maximum time between reports: 3600 seconds (1hr).
This configuration is achieved by sending:
>
STD60120000000803600
<
Now we create event 49 using the
TD6
signal:
>
SED49NV0;TD6+
<
The T&D could also be configured on a time-only basis by defin-
ing the
Minimum Time parameter and setting the others to zero. To
define a time-only criteria of 15 minutes (900 seconds):
>
STD60900000000000000
<
or:
>
STD60900
<
80