TrimTrac ProE Locator Technical Manual v2.0e
74
6.
Use the AT+CTKO? command with a provisioning module to review
logged messages while paying particular attention to the GSM Status
field.
Working with GPRS
If a GPRS session has been established by the mobile device and data is being
actively exchanged between the mobile device and server application, then it is
known conclusively that:
1.
The GSM modem in the device is powered up;
2.
GPRS service is available
1
; and
3.
The device is using GPRS to communicate with the server application.
At any given time, there may be several reasons why there is no active GPRS
session established, including by way of example:
1.
Outside GSM coverage;
2.
Within GSM coverage but no GPRS service is available;
3.
GPRS service is available while roaming, but the SIM card does not have
the appropriate authorization to connect;
4.
The GSM modem is turned off;
5.
Device is configured to used SMS only; or
6.
Device has been configured with incorrect GPRS parameters.
The difficulty, of course, is differentiating between the reasons for the lack of an
active GPRS session when the device has already been deployed in the field.
Other than waiting for the mobile device to establish a new GPRS sessions, the
only other way to communicate with a mobile device for which there is no current
GPRS session is to send it a SMS message. Even so, the device will respond to
appropriately formatted SMS messages sent from the server application if and
only if the device is:
1.
Within GSM coverage;
2.
In a state that has the GSM modem powered up; AND
3.
Configured to communicate via:
4.
SMS-only, or
5.
Either SMS or GPRS and there is no GPRS service available.
It is also important to note that all GPRS communications are, by definition, real
time, meaning that messages can be sent or received if and only if a active GPRS
1
Except when using UDP without the TrimTrac Session Protocol, in which case the device can leave a
GPRS service area but neither the device and server application will know that a GPRS session is no longer
active.
Summary of Contents for ProE Locator
Page 112: ...TrimTrac ProE Locator Technical Manual v2 0e 94 Figure 24 HPA Processing in TRANSMIT ...
Page 113: ...TrimTrac ProE Locator Technical Manual v2 0e 95 Figure 25 MPA Processing in TRANSMIT ...
Page 114: ...TrimTrac ProE Locator Technical Manual v2 0e 96 Figure 26 LPA Processing in TRANSMIT ...
Page 177: ...TrimTrac ProE Locator Technical Manual v2 0e 159 ...
Page 178: ...TrimTrac ProE Locator Technical Manual v2 0e 160 ...
Page 205: ...TrimTrac ProE Locator Technical Manual v2 0e 187 Quick Reference Tables ...
Page 232: ...TrimTrac ProE Locator Technical Manual v2 0e 214 Figure 37 Control Module Wiring Diagram ...