It’s coming along! SNMP is working: your printer responds, and for the first time we can see its four tanks (Black / Cyan / Magenta / Yellow Ink Bottle). That’s already information we didn’t have at all before.
The issue is what it reports for each: -2, which in the protocol means exactly « I don’t know this level ». It’s not the integration that can’t read the value — it’s your printer that declares it doesn’t have it. And there’s a very plausible explanation: on the EcoTank models, the ink is in reservoirs that you fill from bottles, without chips or level sensors. Unlike a classic cartridge, the printer has nothing to measure what’s left — hence the « unknown ». The name it gives itself to its consumables, « Ink Bottle », supports this.
Before concluding, a question that settles it once and for all. What does the Epson application (Smart Panel) or the printer’s screen display regarding ink levels?
- If it doesn’t give any numbers — just a message like « check the reservoirs visually » — then that’s it: the information doesn’t exist anywhere, no software in the world can display it, and I’ll document it as a limitation of this type of printer (with the status, which continues to work).
- If, on the other hand, it displays estimated levels (bars, a percentage), then Epson calculates an estimate somewhere and keeps it in its private channel. In this case, it’s worth going to get it: Epson exposes this kind of data via a proprietary SNMP channel, and it’s feasible.
Your answer tells me whether to dig deeper or stop here — thanks in advance, and especially for your patience on this thread, your feedback has already led to three fixes that benefit everyone. 
