Airlink EDGE/GPRS - Manual (Page 44)

PinPoint-E EDGE/GPRS - User Guide, version 2.32 38
Global Positioning System (GPS)
Datum
In addition to different reporting protocols, the PinPoint-E supports the most widely used GPS
datum. The GPS datum is the method of ascertaining the position of the GPS device using a spe-
cific reference point location. The datum used can influence the accuracy of the GPS positioning.
Datum Supported by the PinPoint-E:
Real-Time Clock Sync
Every hour, the PinPoint-E will sync the internal Real Time Clock (RTC) with the Universal Time
Coordinated (UTC) received from the GPS satellites.
Many tracking applications will translate the time reported by the PinPoint-E as part of the GPS
message to the appropriate local time zone using the UTC offset (i.e. California is UTC-8 and New
York is UTC-5).
TCP GPS Polling
The PinPoint-E can easily and quickly be polled for location by opening a TCP connection to port
9494 (default). Once the connection is established, the PinPoint-E will send a report with the cur-
rent position using the GPS report type the modem is configured to use.
You can change the port for the TCP GPS poll using *TCP.
FIGURE 1. Wireless Ace: *PPTCPPOLL
• WGS84 • NAD83 • NAD27
Note: Wireless Ace displays the current time (UTC) set in the modem and does not
translate it to the local time zone. If the modem is in California and it is 8 a.m., the
modem’s time will be shown as 4 p.m, since UTC is 8 hours “ahead” of Pacific
time (UTC+8).
Note: As a security measure, the TCP connection to the *PPTCPPOLL port must
be from the IP address specified for the ATS Server IP in *PPIP.