First, I am the owner of Chart Navigator Pro. I am desperate for a solution, and the software is based on Coastal Explorer so I decided to seek help here in addition to Maptech. Hopefully someone has solved my problem and can set me straight.

My problem is communications between CNP and my Robertson AP20 autopilot. I have had the same setup on the boat for 8 years and have run both older versions of The Capn and Nobeltec VNS without a problem. Now with CNP the communications with the autopilot is intermittent. Communications can not be established at all if the AP20 is powered up before starting CNP. If I bring up CNP and set a route active before powering up the AP20, the AP20 will indicate receipt of navigation NEMA sentences maybe 25% of the time. The other times it says "no valid data on port". I have tried endless variations in the setup of NEMA0183 sentences, frequency of data transmission, checksum, etc. Anyone else have this problem and figure it out? Thanks