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9100-0425-01
3. Messages
The SmartOne produces on-air messages conforming to the Globalstar specified format. See
Appendix G through J for detailed examples of various message decoding.
The data being communicated to the end user is contained entirely in the 72 bit (9 byte) field.
This section will describe the use of the 9 byte user information segment for communicating the range of
information that the SmartOne is able to convey to the user.
Note:
User information is also referred to as the Message Payload.
Global Message Type
Bits 0 and 1 in the first byte of the user data defines the Global Message Type; there are four total global
types. Types 0 and 3 are applicable to the function and features of the SmartOne, Type 1 and 2 are user
defined message types.
•
Type 0 - Standard Message: All of the various message types that contain Latitude and
Longitude data that are transmitted by the SmartOne will be of this type.
•
Type 1 - Truncated Message: This message type provides for up to 2 bytes plus 6 bits of user
data to be appended to the status byte and GPS location information.
•
Type 2 - Raw Message: This message type provides for up to 8 bytes plus 6 bits of user data.
•
Type 3 - Non Standard Message: This is the message type that covers the category "none of the
above". The SmartOne will use this message type for messages that do not contain Latitude and
Longitude data. Smart One message types which fall into this category include Accumulate/Count
messages, Diagnostic messages, Contact Service Provider messages and Low Battery
messages.
Type 0 Message Class
Message Format
The table below displays the format of all standard messages. Specific variants of the message will be
shown individually in the following subsections.
Byte #
Variable
0
Type Field
0
Battery State
0
GPS Data Valid
Missed Input State
0
Change
0
GPS Fail Counter
Byte #
Variable
1,2,3,4,
Latitude/Longitude
SmartOne Solar™ User Guide v1.0.3
Bits Description
2
Bit (1:0) = 0 - Message Type: Described above.
1
Bit (2) 0 = Good battery. 1 = Replace battery.
Bit (3) 0 = GPS Data valid in this message.
1
1 = GPS failed in this message cycle, ignore Latitude and
Longitude fields.
Bit (4) = Missed Input 1. A value of 1 in this bit means that
an input state change of Input 1 was missed due to the
transmission of a higher priority message.
2
Bit (5) = Missed Input 2. A value of 1 in this bit means that
an input state change of Input 2 was missed due to the
transmission of a higher priority message.
Bit (7:6) = GPS fail counter. Counts up to a maximum
2
value of 3 upon GPS failure.
Bits Description
48
Byte 1 = Latitude MSByte
Confidential & Proprietary Information
10
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