Update - I did implement the WS500 to Cerbo GX (CAN Bus) comm link and have been using it this summer. The short version is that this feature has added a much needed level of visibility into the status of the WS500, including English error messages. Highly recommended.
I also have my Cerbo GX connected to my Raymarine Axiom Pro MFD via Ethernet (RayNet) which allows the Victron app on the MFD to replicate display & control of the Cerbo GX on the MFD at the helm. So the WS500 device data is visible at the helm. Nice!
I also have my Cerbo GX connected to the NMEA2000 bus. So the Cerbo GX broadcasts data from the SmartShunt onto the NMEA2000 bus where it can be displayed by the MFD and other instruments on the bus.
One of the very surprising benefits of having the WS500 connected to the Cerbo GX, to the NMEA2000 bus has to do with the engine RPM. I have the typical Yanmar/VDO tachometer at the helm but it’s old and “sticky” and not very accurate. I was poking around in various displays on my MFD and discovered that the screen that displays engine data is now showing very accurate engine RPM (based on my programming pulley ratios in the WS500). Knock me over. I didn’t have to do anything. Unfortunately, all the data that the WS500 outputs on the CAN Bus is not well documented (I wouldn’t consider Config Guide-Appendix C sufficient). So some experimenting is on the list of things to do to see what other useful WS500 data can be displayed by NMEA2000 connected instruments.
Regarding the custom CAN Bus cable needed for connecting the WS500 to the Cerbo GX: You can purchase a pre-made cable or make you own using the wiring diagram in the WS500/Cerbo documentation. I chose the latter because I don’t like loops of cable stuffed into wiring runs. As for cable length and using extenders, the CAN Bus spec says that maximum cable lengths must be between 500 meters(125 kbps) and 40 meters(1 Mbps). 40 meters probably covers most of our boats. 