Why would I want or need an NMEA Autoswitch?
The NMEA 0183 standard allows any suitably designed marine electronic device to share its gathered information with any other device on a vessel. Unfortunately, there is one very large drawback with this standard - only one device on a connected network can actually send data (a single 'talker' device), with multiple devices (determined by the current limit of the sending unit) listening to that data (multiple listeners).
Secondly, for systems that have multiple NMEA devices of an identical type (e.g. two GPS's or two depth sounders), automatic selection of the highest priority device with valid data is normally a vital requirement. However, the NMEA 0183 standard has no method of automatically switching between different devices, so this requirement is usually fulfilled with a manual changeover switch: not a very good solution, but the only one available until now.
The Actisense NMEA Autoswitch solves both of these problems by allowing up to 4 input devices/talkers, connected through full galvanic opto-isolated inputs, to be analysed, and the NMEA data of the highest priority device automatically switched to the NMEA output.
Can I use an NMEA Multiplexer with my NMEA Autoswitch?
Yes, is the simple answer. The NMEA Autoswitch has been specifically designed to work together with the NMEA Multiplexer / Combiner to create a complete NMEA system solution.
The normal NMEA system would have an Actisense NMEA Autoswitch connected to two (or more) GPS / Depth sounder units. The NMEA Autoswitch adds a special NMEA tag to the data that passes through it to help identify which of these GPS / Depth sounder units supplied the NMEA data.
The autoswitched NMEA output is connected to one of the NMEA Multiplexer's inputs. In this way the highest priority device's NMEA data is autoswitched into the complete NMEA system and the actual device supplying the NMEA data can be determined (and displayed if required and possible) to help the user.
I do not have a serial port on my laptop computer. How can I connect the NMEA Autoswitch to it?
There is a simple solution, use an Actisense USB to Serial adapter cable (USB-1). This cable will convert a USB port on your laptop computer into a fully functional serial communications (RS232) port, allowing the NMEA Autoswitch RS232 output to be connected to a computers USB port.
Simple Plug'n'Play installation and operation makes this a perfect solution.