User's Manual

DRAFT TrimTrac 1.5 Technical Manual v0.3ab 22
Polling
Polling on the TrimTrac 1.5 has been implemented somewhat differently than
earlier generations of the TrimTrac locator. Polling can be implemented on the
TrimTrac 1.5 either based upon motion or regardless of motion. In order to
enable polling, the TrimTrac 1.5 remains connected to the GSM network in states
other than just the TRANSMIT or QUERY states. Connection to the GSM
network requires that the device keep the internal GSM modem powered up and
operating. This, of course, increases power consumption and reduces battery life,
but the ability to more continuous communication with the device may outweigh
these negative side effects.
If communication with the device is required at all times, whether the device is
moving or is at rest, then the Anytime Polling feature is set “2=OnDemand”. The
device will be able to receive and process messages sent from the server
application in virtual real-time, regardless of which state the device may be in at
the time, except when the device itself is already transmitting a message.
As noted above, however, leaving the GSM modem on continuous to support this
Anytime Polling OnDemand capability has a negative impact on power
consumption. To help mitigate this parasitic power drain, it may be useful to
cycle the GSM modem on and off periodically while the device is at rest. This is
the purpose of Duty-Cycled setting for Anytime Polling. When enabled, Duty-
Cylced polling turns off the GSM modem for some pre-defined period while in
the IDLE State (i.e. at rest with no motion) and then turns it back on momentarily
to check for any messages sent by the server application. While the device is in
motion, the GSM modem remains on continuously.
The In-Motion Polling feature is used when polling is to be enable ONLY while
motion is sensed. If no motion is occurring and the device is in the IDLE State,
then the GSM modem will be powered off except as required to process normal
IDLE state messages. While in motion, however, the GSM modem will remain
powered up, thereby allowing continuous connection to the GSM network.
The In-Motion Polling feature is submissive to Anytime Polling, meaning that if
Anytime Polling is enabled, be it set to OnDemand or Duty-Cycled, then the
GSM modem will remain powered during motion regardless of how the In-
Motion Polling feature is set.
If neither Anytime Polling nor In-Motion Polling is enabled, then the device can
only be query, polled, or otherwise communicated with while it is in the QUERY
state only.
Query Hold Flag
The Query Hold Flag is seldom changed for its default configuration. In its
default mode and assuming neither Anytime Polling nor In-Motion Polling is