Table 12. Gsm Polling Options - TrimTrac ProE Locator Technical Manual

Table 12. GSM Polling Options

If communication with the device is required at all times, whether the device is
moving or is at rest, then the Anytime Polling feature can be 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 continuously 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 the 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 enabled ONLY while
motion is being 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.
A popular combination when using SMS messaging is to have In-Motion Polling
set to "1=OnDemand" and Anytime Polling set to "1=Duty Cycled while in
IDLE State". This will allow continuous communication with any device while it
is motion, but then cycle the GSM modem on and off while in the IDLE State to
minimize power consumption but still allowing more frequent polling of the
device than would otherwise be afforded by the expiration of IDLE Timeout, T1,
alone.
Duty cycling the GSM modem while in the IDLE State may result in excessive
GPRS data charges since some carriers charge a minimum number of Bytes (i.e.
1k Bytes) each time a GPRS session is established regardless of how much user
data is actually transmitted during the current GPRS session. Therefore, leaving
the GSM modem on for as long as possible by setting this Anytime Polling to
2=OnDemand may be preferred when using GPRS communications, even if doing
so results in much higher power consumption.
TrimTrac ProE Locator Technical Manual v2.0e 40