MEANWELL_NTU(8)                   NUT Manual                   MEANWELL_NTU(8)

NAME
       meanwell_ntu - Driver for Mean Well NTU series inverter/UPS units

SYNOPSIS
       meanwell_ntu -h

       meanwell_ntu -a UPS_NAME [OPTIONS]

           Note

           This man page documents the hardware-specific features of the
           meanwell_ntu driver. For general information about NUT drivers, see
           nutupsdrv(8).

DESCRIPTION
       The meanwell_ntu driver provides support for Mean Well NTU series
       inverter/UPS units that implement the vendor's ASCII serial protocol.

       This driver is currently experimental and intended for early adopters.
       Reported variables and behavior may evolve as additional models and
       firmware revisions are tested.

SUPPORTED HARDWARE
       The driver is known to work with the following NTU models:

       o   NTU-1200

       o   NTU-1700

       o   NTU-2200

       o   NTU-3200

       Supported DC-voltage variants include:

       o   NTU-1200-112, -124, -148

       o   NTU-1700-112, -124, -148

       o   NTU-2200-112, -124, -148

       o   NTU-3200-212, -224, -248

       Other NTU-series devices using the same protocol may also work.

       Communication uses a 9600-8-N-1 serial connection via RS-232 or a
       USB-serial adapter seen by the operating system as a serial port, e.g.
       /dev/ttyUSB0 (on Linux).

CABLES
       MEAN WELL p/n: RJ11-RS232

       A straight-through serial cable (no modem control) is required.

       USB-to-RS-232 adapters work as long as they expose a standard TTY
       device.

CONFIGURATION
       The driver is configured via ups.conf(5).

       A minimal configuration:

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

   Required parameters
       Example standard parameters:

       driver
           Must be set to meanwell_ntu.

       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
       The following instant commands are supported when the connected
       hardware implements them (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.

STATUS AND VARIABLES
       The driver regularly sends the Q (status) and I (info) commands and
       maps their fields to standard NUT variables.

   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 (<degree>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.

       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.

LIMITATIONS
       This driver is marked experimental:

       o   Protocol interpretation based on limited test samples.

       o   Some fields in Q/I responses are currently unused.

       o   Load and capacity reporting may be refined with further testing.

       o   Shutdown and restart behavior is basic and may not integrate with
           all NUT power-path logic.

       For debugging, run the driver with high verbosity, e.g.:

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

       Please include model, firmware version, and operating mode details when
       reporting issues.

IMPLEMENTATION
       Note the protocol on surface seems related to Megatec Qx, but is
       sufficiently different to warrant a separate driver and not a
       sub-driver of e.g. nutdrv_qx(8).

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:
       o   The NUT (Network UPS Tools) home page:
           https://www.networkupstools.org/historic/v2.8.5/

       o   Vendor documentation:
           https://www.meanwell.com/Upload/PDF/NTS,NTU-E.pdf

Network UPS Tools 2.8.5           04/07/2026                   MEANWELL_NTU(8)