How to enable NMEA output from C120W?

[alavarre]

We need to change the thread title to
How to enable GPS output to NMEA 0183 data bus

Thanks again to all. Ideas anyone? How to turn on the GPS NMEA 0183 output?

Conclusion:
The GPS is not putting its sentences on the NMEA 0183 bus, even though the Autohelm instruments are clearly sending NMEA 0183 sentences, the GPS is functioning (sending position to both the VHF radio and the C120W display), and NMEA 0183 Heading sentences are being presented to and recognized by the RNS 6.2 software.

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Chuck hello.

The question now is:
How to enable GPS NMEA 0183 sentences to the Raymarine 0183 bus?

===== Details =====

This has been a very interesting exercise in wire tracing and analysis. We are making progress.

In short:
• This is entirely a Raymarine installation, no 3rd party instruments.
• The Autohelm Instruments communicate among themselves and the Classic C120W socket #1 on SeaTalkng (I've traced the blue and white striped wiring).
• The laptop is running Linux (openSUSE Leap 42.1).
• The Autohelm instruments transmit NMEA 0183 sentences to a DB-9 RS-232 connection to the laptop (tested). Pins 2, 3, and 5 are respectively White, Yellow, and Brown. If I turn off the Autohelm instruments the sentences stop.
• The RS-232 DB-9 connector connects to the laptop USB port with a GigaWare USB-A to Serial cable.
Under Linux we can read the NMEA 0183 output:
stty -F /dev/ttyUSB0 4800
cat /dev/ttyUSB0
shows autopilot sentences:
$APHDG,93.8,,,,*6A
$APRSA,-26.60,A,,*11
You have identified these as autopilot sentences and indeed RNS 6.2 shows the boat's direction correctly, but not it's position. It also recognizes "Heading" as an instrument.
• The laptop has Oracle VirtualBox installed.
+ VirtualBox recognizes the USB-Serial adapter as a USB device.
• Windows 10 is running inside the VirtualBox.
+ Windows 10 Device Manager recognizes the adapter as USB to Serial Cable (COM4)
• RNS 6.2 is running inside Windows 10.
+ RNS > Setup > Instruments > Automatically Config detects NMEA on COM4 as "Raymarine NMEA 183 Instruments" protocol.
+ RNS > Setup > Instruments > NMEA on COM4 > What is Connected detects only "Heading":
This correlates with the detected autopilot sentences above. So, whether Linux, VirtualBox, Windows 10, or RNS 6.2 the only recognizable NMEA 0183 ASCII stream is autopilot heading and speed, even though GPS is active and providing data to the VHF radio and C120W display on the SeaTalkNG bus.

Conclusion:
The GPS is not putting its sentences on the NMEA 0183 bus, even though the Autohelm instruments are clearly sending NMEA 0183, the GPS is functioning (sending position to both the VHF radio and the C120W display), and NMEA 0183 Heading sentences are being presented to and recognized by the RNS 6.2 software.

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Ideas anyone? How to turn on the GPS NMEA 0183 output?

Thanks again.

Cheers, Andy