I ordered a powered USB hub for further testing:
- It is now possible to use a shielded 2 meter USB extension cable between the hub and the USB GPS. Before the GPS would either not be recognized or disconnect within a short period if time.
- Unfortunately this does not solve the 2nd VE-Direct connected BMV not being recognized after (beta) firmware update with a/the USB device (hub, gps or otherwise) connected
- A plain reboot, not unplugging USB, did resolve getting the 2nd BMV recognized. Not unimportant in remote update context.
Update after more trail and error testing (unavoidable with intermittent issues):
- The 2nd VE-Direct connection inside the housing of the MP-II 5000 GX seems to be affected more (or even only) by the ‘not recognized after firmware upgrade / reboot’ issue.
- Moving the 2nd BMV connection from the 2nd VE-Direct, back to a USB to VE-Direct (duppa, quad isolated USB to rs232) connection, but behind the powered USB hub this time, resolves all reconnection issues (for now).
Preliminary advisory for MP-II xxxx GX devices:
- Do not rely on the internal VE-Direct connection
- Do not use long cabled USB devices directly connected to the GX device
- Do use a good powered USB Hub with a short USB cable to the MP - GX
- Do use good isolated USB to VE-Direct cables from Victron or build one based on the duppa rs232 debug boards (single/quad) that have been reported to provide good results by multiple persons, me included.
