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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: • NTU-1200 • NTU-1700 • NTU-2200 • NTU-3200 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. 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: • Protocol interpretation 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, e.g.: /usr/local/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: • The NUT (Network UPS Tools) home page: https://www.networkupstools.org/ • Vendor documentation: https://www.meanwell.com/Upload/PDF/NTS,NTU-E.pdf Network UPS Tools 2.8.4. 06/12/2026 MEANWELL_NTU(8)
NAME | SYNOPSIS | DESCRIPTION | SUPPORTED HARDWARE | CABLES | CONFIGURATION | INSTANT COMMANDS | STATUS AND VARIABLES | LIMITATIONS | IMPLEMENTATION | AUTHOR | SEE ALSO
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