Force EM7455 GPGSA into Manual 3D fix

I am trying to force the EM7455 GPGSA sentence into a manual 3D fix.

I have a BU-353-S4 USB GPS that I have been using in the interim while I get the EM7455 setup. The output of the NMEA string for that device is:


As you can see, the GPGSA string shows Manual 3D fix and the GPGGA string has our current altitude available. When I use this device in our data acquisition program, it shows all 3D GPS coordinates required.

When I use the EM7455 card (!GPSNMEASENTENCE=F), I get the following strings:


The GPGGA sentence shows our altitude, but as you can see, the GPGSA string is in Automatic mode and a 2D fix. I believe this is the issue why the EM7455 card isn’t passing the 3D GPS coordinates to our data acquisition program.

Any advice on how to fix this?