User guide

GPS Configuration
Rev 1 Oct.13 195
SNF Reliable Mode Store and Forward Reliability: GPS reports are retransmitted if not acknowledged by the
server.
Options are:
• OFF (Unreliable Mode) (default)—If this field is Off, the device does not expect
acknowledgment to any GPS report sent to the server.
• Reliable Mode—A sequence number (1–127) is added to each packet (window). The
server acknowledges every 8th packet. If there is no ACK from the server, ALEOS
pings the server and re-sends the packets when the server responds. If the server
receives packets out of sequence, the server NAKs the first and last missed packets.
ALEOS retransmits the missing packets.
• Simple Reliable Mode—ALEOS attempts to contact the server the configured number
of times, after which it stops attempting to contact the server and discards messages
that cannot be transmitted or received after the configured number of tries. When
contacted, the server responds with the ASCII string UDPACK. For information on
configuring the maximum number of retries see SNF Simple Reliable Max Retries on
page 195. For information on configuring the backoff time, see SNF Simple Reliable
Backoff Time (secs) on page 195.)
• UDP Sequence Mode—A hex sequence number (30–7f) is prepended to the packet.
The server responds with SEQACK and the sequence number. The sequence number
is not stored and is re-initialized when the AirLink device is reset or power cycled.
Unacknowledged packets are dropped after the configured number of retries.
• TCP Listen Mode—This mode is the same as UDP Sequence Mode, except that the
server initiates the connection using TCP. Use this mode if your server is behind a
firewall. If you are using this mode, the AirLink device must have a mobile terminated/
Internet routable IP address.
• TCP—When the AirLink device is out of coverage (no service, the link is down, etc.)
reports are stored until the device can access the server.
Note: You can also use an AT Command to set this field. For more information, see
*PPSNFR on page 358.
SNF Simple Reliable
Max Retries
When the AirLink device is configured to use Simple Reliable Mode, use this field to set the
maximum number of retries when a report is sent and there is no response. Use the SNF
Simple Reliable Backoff Time (secs) field to set the interval between retries.
Options are:
• Disabled
• 1–255 retries (Default is 10.)
You can also use an AT Command to set this value. For more information, see
*PPMAXRETRIES on page 357.
SNF Simple Reliable
Backoff Time (secs)
When the AirLink device is configured to use Simple Reliable Mode, use this field to set the
interval for the retries. (Use the SNF Simple Reliable Max Retries field to set the maximum
number of retries.)
• (Default is 10.)
You can also use an AT Command to set this value. For more information, see
*PPSIMPLETO on page 358.
Additional Data
When configured, these options add additional data to RAP reports (see GPS Report Type on page 191)
sent in response to any trigger.
Table 9-1: GPS: Servers 1–4
Field Description