User's Manual

DRAFT TrimTrac 1.5 Technical Manual v0.3ab 72
Operation of the TrimTrac 1.5 is altered depending upon the status of each monitored
device and status of the alert. By definition, an alert is considered “normal” when in the
condition as shown in Figure 9, Vehicle Adapter Module Alert Wiring Diagram on page
52 and all previous alerts have been cleared (more on clearing of alerts shortly).
An alert is said to have been “Initiated” when its status first changes from the
“0=Normal” to “1=Activated” condition. Initiating an alert is a random event that can
occur when the TrimTrac 1.5 is in any of its operational states (See Figure 4, Summary
TrimTrac Operational State Diagram). How the TrimTrac 1.5 modifies its operational
behavior is dependent upon the type of priority alert being initiated and in what state the
device happens to be in at the time of initiation.
When a High or Medium Priority switch or device changes from its normal condition for
200 mSeconds or more, or upon loss of external power in the case of the Medium Priority
alert, the associated alert is set to “1=Activated”. The exception to this a Low Priority
switch which must be held closed while motion is sensed before its status is changed to
“1=Activated”.
The status of an “Activated” alert will be set to “2=Sent” once the TrimTrac 1.5 has
successfully transmitted the associated message to the GSM network. Depending on the
priority of the alert, the TrimTrac 1.5 will operate in accordance with the associated
configuration unless otherwise instructed by the server application.
Because SMS text messaging or UDP provide no guarantee of delivery, just because the
TrimTrac 1.5 has successfully transmitted the alert message to the GSM network, there is
no guarantee that the server application has in turn received the transmitted alert message.
As such, the TrimTrac 1.5 will continue transmitting the alert messages until it receives
back from the server application an appropriately configured SET_ALERT_STATE
message (See 112), at which time, the alert status can be set “3=Acknowledged”.
Finally, when the device that initiated the alert in the first place is returned to its
“normal” condition, then the alert can be “cleared” upon receipt of an appropriately
configured SET_ALERT_STATE message. If a “clear” command is sent before the
monitor switch or device is returned to its “normal” condition, then a new alert will be
initiated immediately and the clearing process will need to be repeated. If the alert mode
was set to “3=Monitor-only”, then the status of the monitored alert will be automatically
reset to “0=Normal” when the device is reset; however, no separate message to this effect
will be transmitted. The updated status of a monitor-only alert will simply be included in
the next report to be logged.
High Priority Alert Processing
An example of a High Priority Alert could be a manually operated switch or device that
requires immediate and continuous transmission of the resulting alert message until
acknowledged or cleared by the server application.