NMEA output options

If your equipment setup includes additional equipment that requires precise positions, such as ground penetrating radar or sonar systems, you can configure Trimble Access to share positions from the connected GNSS receiver as NMEA‑0183 messages.

To output NMEA‑0183 format messages and send them to the device connected to the GNSS receiver, configure the settings in the NMEA outputs screen of your GNSS survey style.

The NMEA outputs screen is not available with the Trimble DA2 receiver.

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 heights as the job.

If you are using a receiver with IMU tilt compensation:

  • If IMU tilt compensation is enabled and the Use job coordinates check box is selected, the software outputs pole tip (ground) positions, irrespective of whether the IMU is aligned or if the receiver is operating in GNSS‑only mode.
  • If IMU tilt compensation is enabled and the Use job coordinates check box is not selected, the receiver applies the antenna height and outputs pole tip (ground) positions.
  • If IMU tilt compensation is disabled, the receiver outputs antenna phase center (APC) positions.

For GNSS receivers that do not support tilt, heights are output as antenna phase center (APC) heights.

If you are using an R10 or R12 receiver, NMEA output during a compensated point measurement remains antenna phase center (APC) heights. There is no tilt compensation applied to positions in the NMEA messages output in either receiver or job coordinates.

Selecting the Use job coordinates check box limits the available NMEA message types to NMEA GGA, GGK, GLL and PJK messages. Clearing this check box makes more NMEA messages available for output.

Clear the Use job coordinates 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.

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

  1. Select the Receiver port that the additional device is using to connect to the GNSS receiver. The Trimble Access software will output NMEA messages to the same port so that they can be used by the additional device.

    • When using a USB port:

      • If you are using cable PN 80751, from the USB lemo port on the receiver to a USB-A connector, select the USB virtual serial port option.

      • If you are using cable PN 87144, from the USB lemo port on the receiver to a DB9 serial connector, select the USB serial port option.

    • When you select Bluetooth in the Receiver port field, the Trimble Access software assumes the additional device is connected using Bluetooth port 1 on the GNSS receiver.

      To use Bluetooth to output NMEA messages when using a controller running Android, a GNSS receiver with Trimble ProPoint technology must have firmware version 6.28 or later. If the GNSS receiver does not have Trimble ProPoint technology, the receiver must have firmware version 5.68 or later.

  2. Make sure the Baud rate and Parity settings match those set in the device that is receiving the NMEA messages.