ACR Electronics PLB-350C - Manual (Page 7)

Y1-03-0244B 7
The 406 MHz signal is detected by multiple satellites and from that information
the location of the beacon can be calculated. This data alone is sufficient for
SAR to find persons or ships in distress in a reasonable timeframe. However,
as a further enhancement, some beacons have a GPS engine onboard. This
feature allows the beacon to acquire current location coordinates from an
internal GPS receiver. The purpose of this feature is to send an even more
precise location of the beacon to the satellites, i.e., latitude and longitude data.
This helps SAR to reach the location even faster.
2. Internal GPS position system
The PLB-350C is fitted with an internal GPS receiver that will download the
coordinates (latitude and longitude) of the beacon’s position on the globe, to be
transmitted to the Cospas-Sarsat emergency system.
When the beacon is activated, the internal GPS immediately attempts to
acquire positional coordinates. GPS coordinates can be acquired any time that
the GPS is on, but only valid data is saved. Once the beacon acquires valid
coordinates, the data is included as part of the next transmitted 406 MHz digital
message.
The internal GPS operates on a schedule during a beacon activation. The GPS
is on for a time, actively acquiring coordinates, and off for 20 minutes, in a
standby state. The schedule is designed to conserve battery but, at the same
time, assure that navigational coordinates are regularly updated.
3. Optional beacon management and testing services
Additional features and through satellite testing services are available for this
beacon when you subscribe to the SafeLife System. When you sign up for this
optional service you can test your beacon and have confirmation messages
sent to your cell phone or email. Expanded services also will include friends
and family contact information for check in messaging. Visit 406Link.com for
complete details. (This service is not required for your beacon to function as a
Personal Locator Beacon.)