Summary of Contents for i-Lotus M12M
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Page 1: Quick Start Guide
M12M Quick Start Guide Prepared by: i-Lotus Pte. Ltd. Sales & Marketing Department 01 May 2008 M12M™ Quick Start Guide (403-TTN-001) Page 1... -
Page 2: Table Of Contents
M12M Nominal Voltage and Current Ranges ............6 Backup Battery (Externally applied backup power) ..........6 M12M Oncore Receiver Printed Circuit Board Mechanical Drawing ....... 8 Time RAIM Algorithm (M12M Timing Receiver Only) ............. 9 Automatic Site Survey (M12M Timing Receiver Only) ..........10 100PPS Output (M12M Timing Receiver Only) ............ -
Page 3: Overview
Overview This guide 1.1 M12M Positioning Receiver The M12M Oncore is a 12-channel positioning receiver offering one of the fastest Time to First Fix (TTFF) specifications in the industry, and split second reacquisition times. 1.2 M12M Timing Receiver The M12M timing receiver is a variant of the M12M positioning receiver, and its highly optimized firmware makes it one of the most capable timing receivers on the market. -
Page 4: Product Highlights
Product Highlights Features present on all M12M receivers include the following: 12-channel parallel receiver design Code plus carrier tracking (carrier-aided tracking) Position filtering Antenna current sense circuitry Operation from +2.85 to +3.15 Vdc regulated power ... -
Page 5: Receiver Description
The M12M Oncore receiver provides position, velocity, time, and satellite tracking status information via a serial port. A simplified functional block diagram of the M12M receiver is shown below in Figure 3.1. Figure 3.1: M12M Oncore Receiver Functional Block Diagram A chart of the typical output voltage vs. -
Page 6: M12M Nominal Voltage And Current Ranges
Figure 3.2 Antenna drive circuit performance The following table lists the assigned signal connections of the M12M receiver's power/data connector. Pin # Signal Name Description TxD1 Transmit Data (3V logic) RxD1 Receive Commands (3V logic) +3V PWR Regulated 3Vdc Input... - Page 7 5 A typical @ 2.7V and 25C ambient temperature Current: Backup power retains the real-time-clock, position, satellite data, user commanded operating modes, and message formatting. 01 May 2008 M12M™ Quick Start Guide (403-TTN-001) Page 7...
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Page 8: M12M Oncore Receiver Printed Circuit Board Mechanical Drawing
M12M Oncore Receiver Printed Circuit Board Mechanical Drawing Figure 3.4: M12M Oncore Printed Circuit Board Layout with Straight, 0.050" [1.27mm] Pitch, 10 Pin Data Header 01 May 2008 M12M™ Quick Start Guide (403-TTN-001) Page 8... -
Page 9: Time Raim Algorithm (M12M Timing Receiver Only)
Time RAIM Algorithm (M12M Timing Receiver Only) Time Receiver Autonomous Integrity Monitoring (T-RAIM) is an algorithm in Oncore timing receivers (including the M12M T) that uses redundant satellite measurements to confirm the integrity of the timing solution. The T-RAIM approach is borrowed from the aviation community where integrity monitoring is safety critical. -
Page 10: Automatic Site Survey (M12M Timing Receiver Only)
Position/Status/Data Messages (@@Ha and @@Hb) is set. Once the position is surveyed, the M12M timing receiver automatically enters the Position-Hold Mode. At this point, the auto survey flag is cleared and the normal position-hold flag is set in the receiver status byte of the @@Ha and @@Hb messages. -
Page 11: 100Pps Output (M12M Timing Receiver Only)
100PPS Output (M12M Timing Receiver Only) With the M12M timing firmware, the timing output can be selected between 1PPS and 100PPS. This is done using the Pulse Mode command (@@AP). See chapter 5 for information on the formatting of this command. -
Page 12: One Pulse Per Second (1Pps) Timing
One Pulse Per Second (1PPS) Timing Measurement Epoch Timing The M12M receiver timing is established relative to an internal, asynchronous, 1 kHz clock derived from the local oscillator. The receiver counts the 1 kHz clock cycles, and uses each successive 1000 clock cycles to define the time when the measurement epoch is to take place. - Page 13 Position/Status/Data Message, the time output in the message reflects the best estimate of the most recent measurement epoch. A simple timing diagram is shown in figure 3.8. 1PPS Cable Delay Correction and 1PPS Offset (M12M Timing Receiver Only) Users can compensate for antenna cable length with the 1PPS Cable Delay Command (@@Az).
- Page 14 UTC or GPS time depending on the setting of the Time Mode. Operational Considerations When powered on, the M12M Oncore Receiver automatically acquires and tracks satellites; measures the pseudorange and phase data from each of up to twelve satellites; decodes and collects satellite broadcast data;...
- Page 15 N/A - Not applicable. Knowledge of this parameter has no effect on TTFF in this configuration. First Time On When the M12M receiver powers up for the first time after factory shipment, the initial date and time will be incorrect. This will force the receiver into a cold power-up state (cold start), and it will begin to search the sky for all available satellites.
- Page 16 If backup power is available, the M12M retrieves its last known position coordinates from RAM when main power is reapplied, and uses this information in the satellite acquisition algorithm. In addition, the receiver retains the almanac and last used satellite ephemeris as long as the backup power is applied.
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Page 17: O Commands
I/O Commands The Binary commands can be used to initialize, configure, control and monitor the M12M receivers. The binary commands are supported on the primary communications port at 9600 baud. Immediately following this page are listings of the input commands in alphabetical order. - Page 18 UTC Offset Output utcoff Message @@Bp Receiver Request UTC/Ionospheric utcion Data @@Cb Almanac Almanac Data Input almin Table 5.1: Input Commands Listed by Binary Command Header 01 May 2008 M12M™ Quick Start Guide (403-TTN-001) Page 18...
- Page 19 Track Made Good and ----- Speed GPZDA NMEA Time and Date ----- NMEA Switch to Binary ----- Table 5.1: Input Commands Listed by Binary Command Header (continued) 01 May 2008 M12M™ Quick Start Guide (403-TTN-001) Page 19...
- Page 20 10 12 Channel Position/Status/Data Message (@@Ha) This message is the ‘standard’ M12M binary position/status message. The @@Ha message provides position and channel related data to the user at a specified update rate. Default mode: Polled Note: United States export laws prohibit commercial GPS receivers from outputting valid data if the calculated GPS height is greater than 18,000 meters (11 miles) and the calculated 3D velocity is greater than 514 meters/second (1135 miles/hour).
- Page 21 02 = Once every two seconds 03 = Once every three seconds. FF = Once every 255 seconds (maximum). The complete command looks like the following: @@HarC<CR><LF> Where: = checksum <CR> = Carriage return 01 May 2008 M12M™ Quick Start Guide (403-TTN-001) Page 21...
- Page 22 = latitude in mas -324,000,000..324,000,000 (-90º..+90º) oooo = longitude in mas -648,000,000..648,000,000 (-180º..+180º) hhhh = GPS height in cm -100,000..+1,800,000 (-1000..+18,000m)* mmmm = MSL height in cm always 0,000,000 with M12M 01 May 2008 M12M™ Quick Start Guide (403-TTN-001) Page 22...
- Page 23 Satellite Accuracy per para 20.3.3.3.1.3 of ICD-GPS-200 0000 (0) 0.00m <URA<=2.40m 0001 (1) 2.40m <URA<=3.40m 0010 (2) 3.40 m<URA<=4.85m 0011 (3) 4.85m<URA<=6.85m 0100 (4) 6.85m<URA<=9.65m 0101 (5) 9.65m<URA<=13.65m 0110 (6) 13.65m <URA<=24.00m 01 May 2008 M12M™ Quick Start Guide (403-TTN-001) Page 23...
- Page 24 01 = OC 10 = UC 11 = NV Bit 0: Code Location 0 = EXTERNAL 1 = INTERNAL Reserved Oscillator and Clock Parameters: -32768…32767 ns cc = clock bias 01 May 2008 M12M™ Quick Start Guide (403-TTN-001) Page 24...
- Page 25 = ID tag 6 characters (0x20 to 0x7e) C = checksum Message Length: 154 bytes *Represents UTC time offset from GPS time. Offset is rounded to the nearest integer value. 01 May 2008 M12M™ Quick Start Guide (403-TTN-001) Page 25...
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