User's Manual

14
6.2 GPS acquisition with the external GPS
The RLB-36 is tted with an optical interface to connect with an external Global Positioning
System receiver that will determine the latitude and longitude of its position to be transmit-
ted to the emergency system. When RLB-36 is coupled to a working external GPS receiver,
it immediately begins downloading data. Once valid position data has been obtained, the
beacon will attempt to update the positional data every 20 minutes. The RLB-36 will store the
last valid positional data for up to 4 hours, if it becomes unable to obtain new updated data.
It will update this data if and only if it receives new good positional data from the external
GPS receiver.
The black lead wire with white stripes should be connected to the positive transmitter pin.
The black wire should be connected to the negative pin.
If the external GPS receiver is operational and the connection has been correctly made to
the optical interface, the green LED in the optical interface will start ashing.
NOTE: The baud rate output for your GPS receiver NMEA 0183 should be 4800
bps. If you are not sure if your receiver is NMEA 0183 compliant, check the inter-
face settings listed in your GPS manual. To optimize your GPS Interface feature be
sure that your GPS receiver is equipped with a NMEA 0183 Version 1.5 or higher
with GPGGA sentence enabled.
6.3 Using the external GPS interface
Once a compatible, operating GPS receiver is connected to RLB-36, the beacon will store
data for incorporation into the emergency message, which is transmitted to the satellite
when it is activated in an emergency. This can provide more accurate positioning data to
the Search and Rescue Authority and may lead to a faster rescue. Since the last valid GPS
position data may stay in the memory for up to 4 hours, the user
should take care to make sure that the GPS position data stored
is accurate. This can be accomplished by two methods: rst,
by always leaving a properly functioning GPS connected to the
beacon before activation and second, by connecting a properly
functioning GPS with a valid position x and allowing sufcient
time to acquire valid GPS position data. This will take a nominal
20 minutes if old GPS position data is stored in the memory. If
there is no old GPS position data present, the beacon will ac-
quire current data within a minute of being connected to a GPS
with a valid position x. You can force the beacon to update its
position at any time by connecting to a GPS with a valid position
x and initiating the Self-Test. If no valid GPS position data is available, the beacon will keep
the previously stored GPS position data for up to 4 hours. In this case, call ACR Customer
Service at [phone] for instructions on how to reset the beacon with the default
message.
6.4 Testing the external GPS interface
Connect the optical interface plug to the beacon bezel and allow sufcient time for the GPS
receiver to acquire valid GPS position data (usually less than 1 minute; but it can take up to
20 minutes). Lift the thumb switch to the vertical (Self-Test) position and release. Your bea-
con will conrm that it has acquired valid GPS data by displaying the latitude and longitude
coordinates on the display. This will occur after the “smiley faces” are displayed at the end
of Self-Test.
6.5 Updating the external GPS position data
When the beacon is properly connected to a functioning and compatible GPS receiver, GPS
position data is automatically updated about every 20 minutes, while valid GPS position data
NMEA Cable Wires
Figure 7