Can Pylon-Monitor run alongside Solar Assistant, on a stack of six US5000C with different BMS revisions?

Thanks for the kind words!

Battery firmware updates: no, and it's deliberate. The Pylon-Monitor only ever reads from the battery, with the same standard diagnostic commands as Pylontech's own console tool (pwr, info, bat, stat), and never writes anything. Bringing your two newer units to the same BMS revision as the other four is something only Pylontech or your distributor can do, with their service tool. The good news: you don't need them matched for monitoring. The Pylon-Monitor adapts to whatever each battery's console reports, so all six show up correctly either way.

Alongside Solar Assistant: yes. Solar Assistant talks to your batteries over the CAN/RS485 link (and to your Axperts over their own comms). The Pylon-Monitor uses the battery's separate Console port, an independent interface meant for monitoring and diagnostics, so the two don't interfere. Plug the Pylon-Monitor into the Console port of the master battery and leave your Solar Assistant setup exactly as it is.

One thing to check: if your Solar Assistant is wired into the Console port itself (uncommon on Axpert/Voltronic installs, which normally use RS485), that port would already be taken. In a standard setup it is free.