2026-04-26 (afternoon) — LVX6048 parallel-mode commissioning

Got the two LVX6048 inverters operationally paralleled, sharing battery charge from the EG4 LP4 v2 bank symmetrically. Several discoveries about the firmware's parallel-state reporting along the way, plus a couple of small patches.

What happened

Firmware parity (main CPU): achieved. Pre-flash main versions were 06303 (unit 1) and 06440 (unit 2). User flashed both to 06306 using the MPP Solar InfiniVMasterCPU_Reflash tool. Active fault 71 ("Parallel version different") cleared.
Slave-CPU firmware: still skewed but benign. Slaves remain 06126 / 06021. The vendor's LVX6048 FW63.06.zip does include a dsp.hex slave bin, but the operational evidence (load-sharing, matched battery V, no faults, master/slave handshake completing) indicates the slave delta is not blocking parallel function on this firmware family. Not flashing the DSPs — filed for the record only.
Battery wiring + commissioning. Both inverters tied to the same 3× EG4 LP4 v2 100 Ah bank (300 Ah at 51.2 V nominal). After fault 83 ("Parallel battery voltage detect different") cleared on first battery-connected boot, both inverters entered MOD 06 and began sharing the charge load (~55 A each, ~110 A combined ≈ 0.37 C).
MCHGC mismatch (100 A vs 60 A) → fixed. Unit 1 was at 100 A — above the PI18 MCHGC setter's 80 A ceiling, so it had to be set via the LCD (Program 02). User dropped unit 1 to 60 A so both match. Confirmed via flash.py compare (12/12 settings match).
Patch (g) tweak — outputformats/hass.py (unrelated to parallel work but lives in the same patch tree). No change here today; the morning's cleanup is in commit f771ec2.
Patch (h) — pi18.py MOD decoder. Inverter started reporting MOD code 06 after batteries connected; the existing decoder only knew 00..05 and crashed (KeyError: '06'). Added "06": "Charge". The "Charge" label is an educated guess based on observed behavior (active charging, no AC out); revisit if it turns up in unrelated states.
parallel_instance_number decoder fixed. The GS/PGS field is the parallel-instance index per the PI18 spec (0 = master, 1+ = slaves), not a 2-value flag — but powermon upstream (and our patch) was decoding it as ["Not valid", "valid"], which made the master appear as "Not valid" in HA. Replaced with an OPTION decoder labeling each index ("instance 0 (master)", "instance 1", ...) in both GS field 27 and PGS field 0. flash.py sync-check updated accordingly: removed the false-positive "GS parallel_instance_number = Not valid" issue, replaced with index-collision and no-master checks.
lvx-resolve-links now auto-runs on USB hot-plug. Added an ACTION=="add" udev rule for vendor 0665 / product 5161 that RUN+=s systemctl --no-block restart lvx-resolve-links.service powermon.service powermon2.service. Powermon's Requires= / After= already serialize the chain. Added a retry loop to the resolver script (poll up to ~10 s for both expected serials) so a single hidraw appearing slightly before its sibling doesn't leave a symlink missing. Tested via udevadm trigger --action=add --subsystem-match=hidraw: all three services restarted in lock-step and symlinks rewrote cleanly.
Battery profile YAML for the bank. Created lvx-flash/profiles/eg4-lp4-v2.yaml capturing the conservative off-grid LFP policy (USER mode, bulk 56.4 V / float 54.0 V, cutoff 48.0 V, stop-charge 54.0 V). Live state already matches — applying would be a no-op. Kept as the canonical record of the chosen policy.
Sanity dumps — 2026-04-26-lvx6048_{1,2}-dump capture per-unit settings post-commissioning. Useful as a baseline for diff-on-suspect.
Battery side: re-discovered that EG4 LP4 v2's inter-pack daisy-chain silences slave packs. User had wired the inter-pack Link-In/Link-Out chain earlier in the day; it elects a master and demotes slaves on their independent RS485 ports. Pulling the chain restored all three packs to MQTT immediately (all reporting 54.62 V agreement). Daemon needed no change. Memorized for next time.

Net effect

Metric	Before	After
Main-CPU firmware	06303 / 06440	06306 / 06306 ✓
Slave-CPU firmware	06126 / 06021	unchanged (benign)
Active fault 71	yes	cleared
Active fault 83	n/a (no battery)	cleared
MCHGC delta	100 A vs 60 A	60 A / 60 A ✓
Settings parity	mismatch	12/12 match
Charge-current sharing	n/a	55 A / 57 A symmetric
Battery V agreement	n/a	55.1 V / 55.1 V identical
`parallel_instance_number`	"Not valid" / "valid" (master mislabeled)	"instance 0 (master)" / "instance 1"
MOD 06 crash on sync-check	yes	fixed
Hot-plug symlink recovery	manual `systemctl restart`	automatic via udev `RUN+=`

Files touched

M  LVX6048/README.md                           (status section rewrite, sensor count, hot-plug note)
M  LVX6048/powermon-patches/pi18.py            (MOD 06; GS instance-index decoder; PGS validity flag;
                                                two PGS fields named: battery V + capacity)
M  LVX6048/lvx-flash/flash.py                  (instance-index semantics; sync-check rule rewrite;
                                                cutoff <= stop_discharge validator)
M  LVX6048/bin/lvx-resolve-links               (retry loop for hot-plug race)
M  LVX6048/etc/udev/rules.d/99-lvx6048.rules   (ACTION=="add" RUN+= cascade)
A  LVX6048/2026-04-26-lvx6048_1-dump           (post-commissioning baseline)
A  LVX6048/2026-04-26-lvx6048_2-dump           (post-commissioning baseline)
A  LVX6048/lvx-flash/profiles/eg4-lp4-v2.yaml  (canonical battery profile)
A  LVX6048/2026-04-26-parallel.md              (this file)

How to verify

sudo systemctl stop powermon.service powermon2.service
sudo systemctl restart lvx-resolve-links.service   # always run after inverter power-cycle
/home/noise/solar/LVX6048/lvx-flash/flash.py sync-check \
    --device-a /dev/lvx6048-1 --device-b /dev/lvx6048-2
sudo systemctl start powermon.service powermon2.service

Pass criteria post-commissioning:

main fw 06306 on both
mode=06 (Charge) or mode=03 (Battery) or mode=05 (Hybrid) — i.e. healthy operating modes, no 04 (Fault)
fault=No fault on both
both parallel_* values present (one as master/0, one as slave/1)
battery V agreement within ~0.2 V
charge currents within ~5 A symmetric (when both are charging)

Nice-to-have pass

README "Status / pending" section rewritten. Replaced the stale "Next steps / not done" with current state — parallel commissioning done, slave-fw delta intentional, hot-plug recovery automatic. Also bumped the per-inverter sensor count from 29 → 23 in the architecture diagram (post-MQTT-cleanup) and added a "cable moves and inverter power-cycles" paragraph noting the udev auto-recovery.
PGS partial decode (two confirmed fields). Captured PGS0+PGS1 on both units while operating in parallel and cross-referenced against simultaneous GS readings to identify two previously-raw fields:
- field_14 (idx 13) → Battery voltage (parallel view) — V*10
- field_18 (idx 17) → Battery capacity (parallel view) — % Several others have plausible candidates noted in the source comment (charging current, mppt voltage) but couldn't be confirmed without captures under load and during discharge. PGS isn't being polled by powermon today, so naming these doesn't change HA — it just makes future use of the command (or extending the pollers) cleaner.
PGS field 0 reverted from the GS fix. The Parallel instance number field has different semantics in PGS than in GS — live captures show PGS field 0 always returns "1" regardless of the queried instance, so it's a "valid response" flag, not the index. Kept the index labeling on GS (where it really is the unit's own instance number) and reverted PGS to the simpler 2-value flag.
flash.py apply round-trip verified. Ran flash.py diff / apply --confirm against the live state with the eg4-lp4-v2.yaml profile — diff reports no changes, apply correctly says "nothing to do", compare afterward shows 12/12 settings still identical. Validates the apply code path end-to-end on a no-op. Caught one validator bug along the way — cutoff < stop_discharge was strict but the inverter actually accepts cutoff == stop_discharge (which the user has set). Loosened to cutoff <= stop_discharge.

Still pending

(optional) verify MOD 06 label by observing in non-charging states
(optional) finish PGS decode: capture under load + during discharge
(optional, longer horizon) closed-loop BMS comms via the dedicated pack→inverter CAN port; defer until open-loop has been stable for a week and we can baseline SoC accuracy

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