
#TN003
          
 #Summary
          
          Why does the differential light flash on
            and off?
  
 #Problem
          
          seaPro
          incorrectly setup.
  Problem
    with the transmitted differential signal.
#Solution
          
          If this is occurring at short regular intervals, the most likely cause is that seaPro is decoding two sentences from the GPS, a non-differential enabled 
          one such as GLL and a differential enabled one such as GGA.
Select
          “Setup” from the main menu, then “Nav properties”, and then “NMEA
          Rx”. 
      
          Select the GPS sentence as  “GGA” NMEA sentence
Problem with the transmitted
          differential signal
          
          
      Check
        that the GPS is receiving the differential correction.
      
          If using satellite correction service such as WASS / EGNOS the service can be intermittent