User manual GARMIN GPS 36 TRACPAK TECHNICAL SPECIFICATION

[. . . ] GPS 35/36 TracPakTM GPS SMART ANTENNA TECHNICAL SPECIFICATION GARMIN· 1200 E. 151st Street · Olathe, Kansas 66062 · (913) 397-8200 · (913) 397-8282 FAX © 1999 GARMIN Corporation, 1200 E. No part of this manual may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying and recording, for any purpose without the express written permission of GARMIN. GARMIN reserves the right to change or improve their products and to make changes in the content without obligation to notify any person or organization of such changes or improvements. [. . . ] However, the host system should allow the GPS 35/ 36 to remain on for at least 12. 5 minutes after the first satellite is acquired (see Section 4 for more information on status indications). 2) If the internal memory backup battery fails or is not installed while the host system power is off and not connected to standby power, the GPS 35/36 will search the sky as described above. The system designer should be aware of the availability of standby power input to the GPS 35/36 to prevent this situation. 3) If the initial data is significantly inaccurate, the GPS 35/36 will perform an operation known as AutoLocateTM. This procedure is fully automatic and, under normal circumstances, will require about 5 minutes to calculate a navigation solution. NMEA-NMEA0183, Version 1. 5 electrical specification compatible serial output. This output is also CMOS compatible with Black: White: Blue: Purple: Green: Gray: 15 a no load voltage swing of 0. 2Vdc to 4. 8Vdc. This output normally provides ASCII sentences formatted per "NMEA 0183, Version 2. 0". User selectable baud rates of 1200, 2400, 4800, and 9600 are available. If used, a 4VDC to 30 VDC power source is required. 16 SECTION 4 SOFTWARE INTERFACE The GPS 35/36 interface protocol design is based on the National Marine Electronics Association's NMEA 0183 ASCII interface specification, which is fully defined in "NMEA 0183, Version 2. 0" (copies may be obtained from NMEA, P. O. Box 50040, Mobile, AL, 36605, U. S. A. ) and the Radio Technical Commission for Maritime Services' "RTCM Recommended Standards For Differential Navstar GPS Service, Version 2. 0, RTCM Special Committee No. The GPS 35/36 interface protocol, in addition to transmitting navigation information as defined by NMEA 0183, transmits additional information using the convention of GARMIN proprietary sentences. The following sections describe the data format of each sentence transmitted and received by the GPS 35/36. The baud rate selection and RTCM differential GPS input are also described. 4. 1 NMEA RECEIVED SENTENCES The subsequent paragraphs define the sentences which can be received on RXD1 by the GPS 35/36. These sentences are echoed upon receipt to provide handshaking that the appropriate information was received by the GPS 35/36. hh = 1 byte checksum 4. 1. 1 Almanac Information (ALM) $GPALM, <1>, <2>, <3>, <4>, <5>, <6>, <7>, <8>, <9>, <10>, <11>, <12>, <13>, <14>, <15>*hh<CR><LF> The $GPALM sentence can be used to initialize the sensor 17 board's stored almanac information if battery back-up has failed. <1> Total number of ALM sentences to be transmitted by the sensor board during almanac download. This field can be null or any number when sending almanac to the sensor board. This field can be null or any number when sending almanac to the sensor board. Mean anomaly afo clock parameter af1 clock parameter <2> <3> <4> <5> <6> <7> <8> <9> <10> <11> <12> <13> <14> <15> 4. 1. 2 Initialization Information ($PGRMI GARMIN proprietary format) The $PGRMI sentence provides information used to initialize the GPS 35/36 set position and time used for satellite acquisition. Receipt of this sentence by the GPS 35/36 causes the software to restart the satellite acquisition process. If there are no errors in the sentence, it will be echoed upon receipt. [. . . ] After the initial position fix, the date and time of day are calculated using GPS satellite information. The GPS 35/36 uses information obtained from the GPS satellites to add or delete UTC leap seconds and correct the transmitted date and time of day. The transmitted date and time of day for leap second correction follow the guidelines 22 in "National Institute of Standards and Technology Special Publication 432 (Revised 1990)" (for sale by the Superintendent of Documents, U. S. When a positive leap second is required, the second is inserted beginning at 23h 59m 60s of the last day of a month and ending at 0h 0m 0s of the first day of the following month. [. . . ]