User's Manual

Table Of Contents
Page 46SmartOne C User Manual Confidential & Proprietary Information
9100-0410-01 R2.4
MESSAGES
The SmartOne produces on-air messages conforming to the Globalstar proprietary 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 com-
municating 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 define 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
The below table displays the format of all standard messages. Specific variants of the message will be shown
individually in the following subsections.
BYTE # VARIABLE BITS DESCRIPTION
0 TYPE FIELD 2 Bit (1:0) = 0 = message type:
0 BATTERY STATE 1 Bit (2) 0 = Good battery. 1 = Replace battery.
0 GPS DATA VALID 1
Bit (3) 0 = GPS Data valid in this message. 1 = GPS failed in this message cycle,
ignore Latitude and Longitude fields.
0 MISSED INPUT STATE CHANGE 2
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.
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.
0 GPS FAIL COUNTER 2
Bit (7:6) = GPS fail counter. Counts up to a maximum value of 3 upon GPS failure.
1,2,3,4,5,6 LATITUDE/LONGITUDE 48
Byte 1 = Latitude MSByte
Byte 2 = Latitude
Byte 3 = Latitude LSByte
Byte 4 = Longitude MSByte
Byte 5 = Longitude
Byte 6 = Longitude LSByte