User`s guide

Chapter 3 – Receiver Description
Motorola GPS Products - Oncore User’s Guide
Motorola Binary Format (Continued)
Status messages are output at the selected update rate (typically, once per second)
for those messages that contain position, velocity, or time, or can be commanded to
output the data one time upon request. The rate at which the data is output in the
continuous output mode is dependent on the type of data in the message. Table
below shows the rates at which the data messages are output for each type of
message, depending on the setting of the continuous/one-time option that is part of
the input command.
Table 3.11: Data Message Output Rates
*GT Oncore receiver only, **UT Oncore receiver only
OUTPUT MESSAGE TYPE MSG.
ID
CONTINUOUS (m=1…255) ONE TIME
(m=0)
Position/Status/Data Output
Message
Ea At selected update rate When requested
ASCII Position Output
Message*
Eq At selected update rate When requested
Time Raim Setup and Status
Message
En At selected update rate When requested
Almanac Data Output Cb When new almanac available When requested
Visible Satellite Status
Message
Bb When visibility data changes When requested
UTC Offset Status** Bo When UTC offset data
available or when it changes
When requested
Leap Second Pending
Status
Bj Not available When requested
For the case where more than one output message is scheduled during the same one
second interval, the GPS receiver will output all scheduled messages but will attempt
to limit the total number of bytes transmitted each second to 800 bytes. For the case
of multiple output messages, if the next message to be sent fits around the 800 byte
length goal, then the message will be output. For example, if messages totaling 758
bytes are scheduled to be sent, and the user requests another 58 byte message, then
816 bytes will actually be sent. If the user requests y
et another 86 byte message, then
its output will be left pending and will be scheduled when the total number of output
bytes allows.
If external battery power is applied during the power-off state, the polled or
continuous option of each output message is remembered in the Oncore receiver
RAM memory.
The UT Oncore timing receiver supports the timing capabilities via the Motorola
binary I/O format. Non-timing receivers will not respond to, nor create, the timing I/O
messages.
Revision 5.0 08/30/02
3.36