MEANWELL_NTU(8)

📦
version 2.8.5 · 4 versions
, in fedora 43, fedora 44

💖 MEANWELL_NTU 💖 — the meanwell_ntu manual, page 8, bestie edition 🎀

okay so. sit down, grab a strawberry, because we're talking about meanwell_ntu, a driver from the NUT Manual. it's a NUT (Network UPS Tools) driver. it's experimental. it's giving "early adopter chaos" and honestly? we love her anyway. 💅

✨ NAME ✨

meanwell_ntu — the driver for Mean Well NTU series inverter/UPS units 🦋

✨ SYNOPSIS ✨

note, bestie, read this: this man page is all about the hardware-specific stuff for the meanwell_ntu driver. for the general "how do NUT drivers even work" tea, go read nutupsdrv(8). 🫶

✨ DESCRIPTION ✨

so basically the meanwell_ntu driver supports Mean Well NTU series inverter/UPS units that speak the vendor's ASCII serial protocol. that's the whole vibe. 🌸

lowkey important: this driver is currently experimental and it's meant for early adopters — the ones who like living on the edge. the reported variables and the behavior may evolve as more models and firmware revisions get tested. so if something shifts under you, that's not a bug, that's just her growing. 😭

✨ SUPPORTED HARDWARE ✨

the driver is known to work with these NTU models:

  • NTU-1200
  • NTU-1700
  • NTU-2200
  • NTU-3200

and the supported DC-voltage variants include:

  • NTU-1200-112, -124, -148
  • NTU-1700-112, -124, -148
  • NTU-2200-112, -124, -148
  • NTU-3200-212, -224, -248

other NTU-series devices using the same protocol may also work — no promises, but she might slay for you too. ✨

communication runs over a 9600-8-N-1 serial connection, via RS-232 or a USB-serial adapter that the operating system sees as a serial port — like /dev/ttyUSB0 on Linux. 🐧

✨ CABLES ✨

MEAN WELL p/n: RJ11-RS232 🔌

you need a straight-through serial cable (no modem control). that's the requirement, periodt.

USB-to-RS-232 adapters work as long as they expose a standard TTY device. that's it, that's the whole thing. 💜

✨ CONFIGURATION ✨

the driver gets configured via ups.conf(5).

here's a minimal configuration, look at her:

[meanwell-ntu]
    driver = meanwell_ntu
    port   = /dev/ttyUSB0
    desc   = "Mean Well NTU-1200-124"

Required parameters 👑

example standard parameters, bestie:

  • driver — must be set to meanwell_ntu. no substitutions, no nicknames.
  • port — the serial/USB tty device (e.g. /dev/ttyS0, /dev/ttyUSB0).

Optional parameters 🎀

this driver currently relies only on standard NUT parameters:

  • pollinterval — interval between status polls (default: 2 seconds).
  • synchronous — serial I/O mode as documented in nutupsdrv(8).

✨ INSTANT COMMANDS ✨

these instant commands are supported when the connected hardware implements them (go see upscmd(8)):

  • load.off — request shutdown of inverter output and load power-off (vendor command C100000000000000).
  • load.on — request inverter output power-on (vendor command C010000000000000).
⚠️ support varies across firmware revisions. test before relying on them. fr fr. don't just trust her, verify her. 💀

✨ STATUS AND VARIABLES ✨

the driver regularly sends the Q (status) and I (info) commands and maps their fields to standard NUT variables. it's basically her little group chat with the hardware. 📲

Selected read-only variables 🔍

  • battery.voltage — battery/DC bus voltage (V).
  • battery.charge — remaining capacity (%).
  • battery.alarm.voltage — low-voltage alarm threshold (V).
  • battery.shutdown.voltage — low-voltage shutdown threshold (V).
  • input.voltage — utility AC input voltage (non-zero in line or bypass mode).
  • output.voltage — inverter output voltage (V).
  • output.frequency — output frequency when running on battery (Hz).
  • ups.temperature — inverter temperature (°C).
  • ups.load — approximate load percentage, derived from PPP bits.
  • device.mfr — manufacturer string (typically MEANWELL).
  • device.model, ups.model — model descriptor (e.g. NTU-1200-124).
  • device.serial — serial number when reported.
  • device.firmware — firmware revision string.

UPS status flags 🚩

the NTU protocol exposes a 19-bit status word. iconic, honestly.

the driver maps selected bits into ups.status keywords:

  • OB — on battery / inverter mode.
  • BYPASS — bypass mode active.
  • OL — utility present / online.
  • LB — battery low.
  • OVER — over-temperature condition.

the raw bit fields are also exported as informational variables such as battery.low, utility.present, bypass.mode, overtemp, etc. she's transparent like that. 👑

✨ LIMITATIONS ✨

this driver is marked experimental, and we're gonna be honest about it:

  • protocol interpretation is based on limited test samples.
  • some fields in Q/I responses are currently unused.
  • load and capacity reporting may be refined with further testing.
  • shutdown and restart behavior is basic and may not integrate with all NUT power-path logic.

for debugging, run the driver with high verbosity, like:

/usr/local/ups/bin/meanwell_ntu -DDDDD -a meanwell-ntu

please include model, firmware version, and operating mode details when reporting issues. give us the receipts so we can actually help. 🙏

✨ IMPLEMENTATION ✨

ngl, the protocol on the surface seems related to Megatec Qx — but it's sufficiently different to warrant a separate driver, and not a sub-driver of e.g. nutdrv_qx(8). so she stands on her own. main character energy only. 💅

✨ AUTHOR ✨

the meanwell_ntu driver was contributed by Jonathan Hite. 🫶

additional improvements may be provided by the NUT community. see the project repository for revision history.

✨ SEE ALSO ✨

ups.conf(5), nutupsdrv(8), upsd(8), upsmon(8), upsc(8), upscmd(8)

Internet resources 🌈

okay that's the whole page, bestie, you ate. this was Network UPS Tools 2.8.5, dated 10/07/2026 — and it's MEANWELL_NTU(8), out. slay, stay powered, and go plug in your UPS. 🔥💖✨

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