by artmart » Wed Apr 25, 2012 2:00 pm
Your issue made plenty of sense to me. That was actually a good question, to remind us that if a device does not meet the NMEA standard, there is another method that might work but requires some research on what the serial attributes should be via the TLDCN or RTN Serial options. This might be better than nothing.
NMEA is a serial interface that is standardized to provide navigation information. Before the standard was introduced the interface required the use of very standard and basic serial interface (aka RS-232). The problem with RS232 is that the information itself was not standardized so that only basic information could be provided and the devices on either end needed to be able to understand what to do with the information. This led to huge incompatibilities between devices.
NMEA standardized this to make it easier and add more capabilities and any device developed to support NMEA could automatically understand and communicate with any other device supporting the same NMEA standard for navigation and coordinate transfers. While still not perfect it is way better than the old non-NMEA method.
Art Martinez
Murrieta, CA