Garmin GPS 35 LP Technical Specification

Also see for GPS 35 LP: Declaration of conformity Quick start guide Technical specification

Contents

Garmin GPS 35 LP Technical Specification Manual pdf 27 page image

234.3 Baud Rate SelectionBaud rate selection can be performed by sending the appropriate configuration sentence to the sensorboard as described in the NMEA input sentences selection. (Section 4.1)4.4 One-Pulse-Per-Second OutputThe highly accurate one-pulse-per-second output is provided for applications requiring precise timingmeasurements. The signal is generated after the initial position fix has been calculated and continuesuntil power down. The rising edge of the signal is synchronized to the start of each GPS second.Regardless of the selected baud rate, the information transmitted by the GPS 35LP receiver isreferenced to the pulse immediately preceding the NMEA 0183 RMC sentence.The accuracy of the one-pulse-per-second output is maintained only while the GPS 35LP can compute avalid position fix. To obtain the most accurate results, the one-pulse-per-second output should becalibrated against a local time reference to compensate for cable and internal receiver delays and thelocal time bias.The default pulse width is 100 msec, however; it may be programmed is 20 msec increments between 20msec and 980 msec as described in $PGRMC Section 4.1.3 character <13>.4.5 RTCM Received DataPosition accuracy of less than 5 meters can be achieved with the GPS 35LP by using Differential GPS(DGPS) real-time pseudo-range correction data in RTCM SC-104 format, with message types 1, 2, 3,and 9. These corrections can be received by the GPS 35LP receiver on RXD2. Correction data atspeeds of 300, 600, 1200, 2400, 4800 or 9600 baud can be utilized, as the GPS 35LP automaticallydetects the incoming baud rate. For details on the SC-104 format, refer to RTCM Paper 134-89/SC 104-68 by the Radio Technical Commission for Maritime Services.