Q: How can I output only RMC Sentences? 

A: Please Follow the following Steps:

1. Download latest GetacGPSCommand.exe from https://gps.getac.com
2. Unzip the zip file
3. Open command prompt and change directory to the folder where GetacGPSCommand.exe is
4. Type or paste in GetacGPSCommand.exe 2 9600 "$PMTK314,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0*29"
5. Press enter
6. Type GetacGPSCommand.exe 2 9600 and press enter (This will show the GPS Strings for 10 seconds and should now only be RMC)
7. Close Command Window and test in your software.