Dbus-cgwacs / Carlo Gavazzi EM530 issue

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Subject: Request for fix for EM530 measuring-system reset (dbus-cgwacs)

I am working with an Ekrano GX running Venus OS 3.70 and a Carlo Gavazzi EM530 energy-meter on RS-485.

The meter repeatedly flips from 2-phase (2P3W) to 3-phase (3 P + N) every time power or the USB-RS-485 connection is cycled.

I’ve traced this to the dbus-cgwacs driver re-writing the meter’s Measuring System register at startup—the same behavior changed in commit fe2055d037230b198b82654085728d3a702a591d.

To resolve the issue I’ve been attempting to build a patched dbus-cgwacs that omits that write, but the build depends on the private submodule victronenergy/velib, which I don’t currently have permission to fetch.

Would you please correct this erroneous action of overwriting the EM530 meters settings by:

  1. Changing dbus-cgwacs binary to stop the behavior or
  2. Grant my GitHub account read-only access to victronenergy/velib (and any other private submodules needed by dbus-cgwacs) or
  3. Provide a source bundle or pre-built Ekrano (imx8m) dbus-cgwacs binary containing the one-line fix (skip writing the Measuring System on connect).

This change will prevent the EM530 from resetting to 3 P + N and allow stable split-phase operation.

Thank you very much for your help.

2

I can confirm that the Victron code does this. I used to go over to the EM530 and change to split-phase via the menus after rebooting my Cerbo GX because it annoyed me.

The only effect that I remember seeing is the appearance of L3 in the console boxes at 0 W.

I’ve chosen to write my own emulation of the EM530, which explicitly ignores this command, but that’s a lot of work to do for only that reason.

3

Use instead a disassembler (like IDA Pro) and “nop” that write at binary level.