TrimTrac ProE Locator, Техническое руководство

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TrimTrac ProE Locator Technical Manual v2.0e 32
through. The only way to get true confirmation that the server application receive
the message is for the server application to positively confirm back to the TrimTrac
ProE that the message had indeed arrived safely. When set to “Automatic”, the
TrimTrac ProE will continuously re-transmit priority alert messages until
acknowledged, or cleared, by the server application.
Network Acknowledgement
If an application requires a less stringent level of send-receive acknowledgement,
then the Alert Mode can be set to “Network Acknowledgement”. In this mode, it is
assumed that the application server has also received any message that is confirmed
to have been received by the GSM network. This provides a lower level of delivery
certainly, but if used with TCP/IP in particular, may provide an acceptable level of
acknowledgement.
When set to “2=Network Acknowledgement”, the TrimTrac ProE will accept an
acknowledgment directly from the GSM protocol stack that the message had been
sent to the GSM network and, presumably, received by the server application. Given
the store-and-forward, non-guaranteed delivery nature of SMS and UDP, however,
relying upon a GSM network acknowledgement may be risky. Use of TCP/IP over
GPRS provides an added layer of delivery certainly compared to both SMS and
UDP. The only way to guarantee that the server application has received the alert
message, regardless of which protocol is used, remains the application level
acknowledgement protocol enabled when the input mode is set “0=Automatic”.
Monitor-only
When the input mode is set “3=Monitor-only”, activation of the input will not in and
by itself cause a new message to be transmitted to the server application. Rather, the
status of the input (i.e. Alert Status set “4=Monitor Activated”) will be indicated in
all subsequent position and status messages that the TrimTrac would otherwise send
to the server application. No SET_ALERT_STATE messages are required to either
acknowledge or clear the alerts. Once the monitored devices or conditions have been
returned to “normal”, then the input status will be updated to “0=Normal”
accordingly.
LPA Input Delay
In earlier versions of TrimTrac, a Low Priority Alert would become “armed”
whenever the monitored switch was closed for 250 mSeconds or longer and become
“activated” upon any detection of subsequent motion. This “armed-activation”
sequence proved too rapid for some applications that required a delay from the time
the monitored switch was closed before the Low Priority Alert became “armed”. As
such, TrimTrac ProE has a programmable input delay that postpones the arming of
the LPA. This feature is expected to be useful when the LPA is used to monitor a
vehicle security system. After the vehicle security system itself is armed, then the
TrimTrac ProE itself will become armed after the LPA Input Arming Delay, T31,
countdown timer expires. See AT+CTKZ Daily Hours, Runtime & Other Extended
Settings on page 134 and SET_EXT2_APP_CONFIG on page 152.