NMEA output options
To output NMEA‑0183 format messages from a port on the connected GNSS receiver, configure the settings in the NMEA outputs screen of your GNSS survey style.
Use job coordinates
Select the Use job coordinates check box if you want the selected NMEA messages to be generated by the Trimble Access software so that they use the same coordinates and antenna phase center (APC) heights as the job. If you select this check box the available NMEA message types are limited to NMEA GGA, GGK, GLL and PJK messages.
Clear this check box if you want the selected NMEA messages to be generated by the receiver so that they use the height reference available in the receiver. For orthometric heights this means the geoid model built into the receiver firmware is used, not the one used by the job. Clearing this check box makes more NMEA messages available for output.
NMEA output is always the position of the antenna phase center (APC). NMEA output during a compensated point measurement remains the APC; there is no tilt compensation applied to positions in the NMEA messages output in either receiver or job coordinates.
Messages to output
Select the message types to output, and the rate at which each message type is output. When the Use job coordinates check box is selected, rates faster than 1s apply only to positions generated during stakeout.
Serial port settings
Make sure the serial port settings match those set in the device that is receiving the NMEA messages.
Advanced settings
The Advanced settings group box contains configuration items that affect the format of the NMEA messages that are output.
The IEC extensions, and the setting of the GST message to GPGST rather than GLGST or GNGST at all times, are available only when using NMEA generated by the receiver firmware, where the Use job coordinates check box is not selected.
Include IEC61162‑1:2010 GNSS extensions
This setting selects which standard to use for the compliant messages. When not selected the NMEA messages comply with NMEA‑0183 Standard for Interfacing Marine Electronic Devices, Version 4.0, November 1, 2008. When selected, the messages comply with the International Electrotechnical Commission (IEC) 61162‑1, Edition 4 2010–11.
Max. DQI=2 in GGA
When selected, the Quality Indicator field in the GGA output message is never greater than 2 (DGPS). This is to support legacy systems that do not fully support the NMEA standard.
Max. age 9s in GGA
When selected, the age of differential data field in the GGA message is never greater than 9 seconds. This is to support legacy systems that do not fully support the NMEA standard.
Extended GGA/RMC
Select this check box to output high precision position data in the NMEA messages. Clear this check box to conform to the NMEA standard message length of 82 characters. If cleared, the precision of the position and height data is reduced by truncating the number of decimal places.
GP always
When selected, the NMEA talker ID is always $GP for NMEA GST, GGA, and GLL messages regardless of the constellation(s) being tracked. For receiver firmware versions earlier than v5.10, the GP always setting applies only to the GST message type.
