'\" t
.\"     Title: meanwell_ntu
.\"    Author: [see the "AUTHOR" section]
.\" Generator: DocBook XSL Stylesheets vsnapshot <http://docbook.sf.net/>
.\"      Date: 04/07/2026
.\"    Manual: NUT Manual
.\"    Source: Network UPS Tools 2.8.5
.\"  Language: English
.\"
.TH "MEANWELL_NTU" "8" "04/07/2026" "Network UPS Tools 2\&.8\&.5" "NUT Manual"
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.SH "NAME"
meanwell_ntu \- Driver for Mean Well NTU series inverter/UPS units
.SH "SYNOPSIS"
.sp
\fBmeanwell_ntu\fR \-h
.sp
\fBmeanwell_ntu\fR \-a \fIUPS_NAME\fR [\fIOPTIONS\fR]
.if n \{\
.sp
.\}
.RS 4
.it 1 an-trap
.nr an-no-space-flag 1
.nr an-break-flag 1
.br
.ps +1
\fBNote\fR
.ps -1
.br
.sp
This man page documents the hardware\-specific features of the \fBmeanwell_ntu\fR driver\&. For general information about NUT drivers, see \fBnutupsdrv\fR(8)\&.
.sp .5v
.RE
.SH "DESCRIPTION"
.sp
The \fBmeanwell_ntu\fR driver provides support for Mean Well NTU series inverter/UPS units that implement the vendor\(cqs ASCII serial protocol\&.
.sp
This driver is currently experimental and intended for early adopters\&. Reported variables and behavior may evolve as additional models and firmware revisions are tested\&.
.SH "SUPPORTED HARDWARE"
.sp
The driver is known to work with the following NTU models:
.sp
.RS 4
.ie n \{\
\h'-04'\(bu\h'+03'\c
.\}
.el \{\
.sp -1
.IP \(bu 2.3
.\}
NTU\-1200
.RE
.sp
.RS 4
.ie n \{\
\h'-04'\(bu\h'+03'\c
.\}
.el \{\
.sp -1
.IP \(bu 2.3
.\}
NTU\-1700
.RE
.sp
.RS 4
.ie n \{\
\h'-04'\(bu\h'+03'\c
.\}
.el \{\
.sp -1
.IP \(bu 2.3
.\}
NTU\-2200
.RE
.sp
.RS 4
.ie n \{\
\h'-04'\(bu\h'+03'\c
.\}
.el \{\
.sp -1
.IP \(bu 2.3
.\}
NTU\-3200
.RE
.sp
Supported DC\-voltage variants include:
.sp
.RS 4
.ie n \{\
\h'-04'\(bu\h'+03'\c
.\}
.el \{\
.sp -1
.IP \(bu 2.3
.\}
NTU\-1200\-112, \-124, \-148
.RE
.sp
.RS 4
.ie n \{\
\h'-04'\(bu\h'+03'\c
.\}
.el \{\
.sp -1
.IP \(bu 2.3
.\}
NTU\-1700\-112, \-124, \-148
.RE
.sp
.RS 4
.ie n \{\
\h'-04'\(bu\h'+03'\c
.\}
.el \{\
.sp -1
.IP \(bu 2.3
.\}
NTU\-2200\-112, \-124, \-148
.RE
.sp
.RS 4
.ie n \{\
\h'-04'\(bu\h'+03'\c
.\}
.el \{\
.sp -1
.IP \(bu 2.3
.\}
NTU\-3200\-212, \-224, \-248
.RE
.sp
Other NTU\-series devices using the same protocol may also work\&.
.sp
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)\&.
.SH "CABLES"
.sp
MEAN WELL p/n: RJ11\-RS232
.sp
A straight\-through serial cable (no modem control) is required\&.
.sp
USB\-to\-RS\-232 adapters work as long as they expose a standard TTY device\&.
.SH "CONFIGURATION"
.sp
The driver is configured via \fBups.conf\fR(5)\&.
.sp
A minimal configuration:
.sp
.if n \{\
.RS 4
.\}
.nf
[meanwell\-ntu]
    driver = meanwell_ntu
    port   = /dev/ttyUSB0
    desc   = "Mean Well NTU\-1200\-124"
.fi
.if n \{\
.RE
.\}
.SS "Required parameters"
.sp
Example standard parameters:
.PP
\fBdriver\fR
.RS 4
Must be set to
meanwell_ntu\&.
.RE
.PP
\fBport\fR
.RS 4
The serial/USB tty device (e\&.g\&.
/dev/ttyS0,
/dev/ttyUSB0)\&.
.RE
.SS "Optional parameters"
.sp
This driver currently relies only on standard NUT parameters:
.PP
\fBpollinterval\fR
.RS 4
Interval between status polls (default: 2 seconds)\&.
.RE
.PP
\fBsynchronous\fR
.RS 4
Serial I/O mode as documented in
\fBnutupsdrv\fR(8)\&.
.RE
.SH "INSTANT COMMANDS"
.sp
The following instant commands are supported when the connected hardware implements them (see \fBupscmd\fR(8)):
.PP
\fBload\&.off\fR
.RS 4
Request shutdown of inverter output and load power\-off (vendor command
C100000000000000)\&.
.RE
.PP
\fBload\&.on\fR
.RS 4
Request inverter output power\-on (vendor command
C010000000000000)\&.
.RE
.sp
Support varies across firmware revisions; test before relying on them\&.
.SH "STATUS AND VARIABLES"
.sp
The driver regularly sends the Q (status) and I (info) commands and maps their fields to standard NUT variables\&.
.SS "Selected read\-only variables"
.PP
\fBbattery\&.voltage\fR
.RS 4
Battery/DC bus voltage (V)\&.
.RE
.PP
\fBbattery\&.charge\fR
.RS 4
Remaining capacity (%)\&.
.RE
.PP
\fBbattery\&.alarm\&.voltage\fR
.RS 4
Low\-voltage alarm threshold (V)\&.
.RE
.PP
\fBbattery\&.shutdown\&.voltage\fR
.RS 4
Low\-voltage shutdown threshold (V)\&.
.RE
.PP
\fBinput\&.voltage\fR
.RS 4
Utility AC input voltage (non\-zero in line or bypass mode)\&.
.RE
.PP
\fBoutput\&.voltage\fR
.RS 4
Inverter output voltage (V)\&.
.RE
.PP
\fBoutput\&.frequency\fR
.RS 4
Output frequency when running on battery (Hz)\&.
.RE
.PP
\fBups\&.temperature\fR
.RS 4
Inverter temperature (\(deC)\&.
.RE
.PP
\fBups\&.load\fR
.RS 4
Approximate load percentage, derived from PPP bits\&.
.RE
.PP
\fBdevice\&.mfr\fR
.RS 4
Manufacturer string (typically
MEANWELL)\&.
.RE
.PP
\fBdevice\&.model\fR, \fBups\&.model\fR
.RS 4
Model descriptor (e\&.g\&.
NTU\-1200\-124)\&.
.RE
.PP
\fBdevice\&.serial\fR
.RS 4
Serial number when reported\&.
.RE
.PP
\fBdevice\&.firmware\fR
.RS 4
Firmware revision string\&.
.RE
.SS "UPS status flags"
.sp
The NTU protocol exposes a 19\-bit status word\&.
.sp
The driver maps selected bits into ups\&.status keywords:
.PP
\fBOB\fR
.RS 4
On battery / inverter mode\&.
.RE
.PP
\fBBYPASS\fR
.RS 4
Bypass mode active\&.
.RE
.PP
\fBOL\fR
.RS 4
Utility present / online\&.
.RE
.PP
\fBLB\fR
.RS 4
Battery low\&.
.RE
.PP
\fBOVER\fR
.RS 4
Over\-temperature condition\&.
.RE
.sp
The raw bit fields are also exported as informational variables such as \fBbattery\&.low\fR, \fButility\&.present\fR, \fBbypass\&.mode\fR, \fBovertemp\fR, etc\&.
.SH "LIMITATIONS"
.sp
This driver is marked experimental:
.sp
.RS 4
.ie n \{\
\h'-04'\(bu\h'+03'\c
.\}
.el \{\
.sp -1
.IP \(bu 2.3
.\}
Protocol interpretation based on limited test samples\&.
.RE
.sp
.RS 4
.ie n \{\
\h'-04'\(bu\h'+03'\c
.\}
.el \{\
.sp -1
.IP \(bu 2.3
.\}
Some fields in
Q/I
responses are currently unused\&.
.RE
.sp
.RS 4
.ie n \{\
\h'-04'\(bu\h'+03'\c
.\}
.el \{\
.sp -1
.IP \(bu 2.3
.\}
Load and capacity reporting may be refined with further testing\&.
.RE
.sp
.RS 4
.ie n \{\
\h'-04'\(bu\h'+03'\c
.\}
.el \{\
.sp -1
.IP \(bu 2.3
.\}
Shutdown and restart behavior is basic and may not integrate with all NUT power\-path logic\&.
.RE
.sp
For debugging, run the driver with high verbosity, e\&.g\&.:
.sp
.if n \{\
.RS 4
.\}
.nf
/usr/local/ups/bin/meanwell_ntu \-DDDDD \-a meanwell\-ntu
.fi
.if n \{\
.RE
.\}
.sp
Please include model, firmware version, and operating mode details when reporting issues\&.
.SH "IMPLEMENTATION"
.sp
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\&. \fBnutdrv_qx\fR(8)\&.
.SH "AUTHOR"
.sp
The \fBmeanwell_ntu\fR driver was contributed by Jonathan Hite\&.
.sp
Additional improvements may be provided by the NUT community\&. See the project repository for revision history\&.
.SH "SEE ALSO"
.sp
\fBups.conf\fR(5), \fBnutupsdrv\fR(8), \fBupsd\fR(8), \fBupsmon\fR(8), \fBupsc\fR(8), \fBupscmd\fR(8)
.SS "Internet resources:"
.sp
.RS 4
.ie n \{\
\h'-04'\(bu\h'+03'\c
.\}
.el \{\
.sp -1
.IP \(bu 2.3
.\}
The NUT (Network UPS Tools) home page:
https://www\&.networkupstools\&.org/historic/v2\&.8\&.5/
.RE
.sp
.RS 4
.ie n \{\
\h'-04'\(bu\h'+03'\c
.\}
.el \{\
.sp -1
.IP \(bu 2.3
.\}
Vendor documentation:
https://www\&.meanwell\&.com/Upload/PDF/NTS,NTU\-E\&.pdf
.RE