The NovAtel and Sokkia GPS options, like Ashtech, allow for hard and soft resets, permit sending commands to the receiver (consult your dealer) and allow the review and re-setting of base and rover radio channels for Pacific Crest PDL and RFM series radios. Additional options check the communication status (shows the quality of the message string). The Review REF File will display the reference file (which stores the GPS base position information), which also helps in troubleshooting.