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iSTAT M365

Power Quality Metering with Extensive Logging and Communications

The iSTAT M365 comprehensive power quality metering and communication features are ideal for utility, industrial and commercial power quality applications. The iSTAT M365 is an enhancement to the previous iSTAT M355 offering with extensive power quality perspective with the latest IEC61000-4-30 Class A Edition 3 certification as well as supporting EN50160 reporting.

With 625 samples/cycle sampling frequency and 8GB of logging memory to capture waveform, disturbance events and measured values, users are empowered to assess and make power related decisions quickly and effectively as well as record data for reconciliation and service level evidence. The iSTAT M365 support of Modbus, DNP3, FTP and IEC 61850 Edition 2 along with GPS, IRIG-B and NTP time sync make it easy to integrate into new or existing systems.

Advanced Monitoring and Metering

  • Class 0.2S active energy accuracy (IEC 62053-22)

  • Harmonics to the 63rd order (Voltage, Current)

  • Up to 625 samples/cycle waveform/transient recording

  • 8 GB of memory for waveform and disturbance recording

  • Class A IEC 61000-4-30 updated Edition 3 Power quality measurement and EN50160 reporting support


Advanced Communications and Control

  • Standard communications Ethernet (RJ45), USB 2.0 and Serial (RS232, RS485 for either time sync or protocol communications)

  • Supports Modbus, DNP 3.0, FTP and optionally IEC 61850 Ed. 2 Protocols

  • Easy system integration with four available I/O modules with up to 20 I/O


User Friendly with Low Commissioning Effort

  • Available 5.7” color TFT display or 128x64 pixel display

  • Universal power supply

  • Easy to install 144mm square panel mounting

  • Web page for easy monitoring of measurements and settings


iSTAT 365 is ideal for energy and power quality monitoring in applications such as utility substations, renewables, advanced industrial manufacturing, datacenters and hospitals with the key features of:

  • IEC 61000-4-30 Class A Edition 3 certification supporting the latest power quality reporting standards

  • High resolution waveform recording requirements (up to 625 samples/cycle) and Class 0.2S Active energy metering accuracy with demand recording

  • Standard 8GB logging memory with PQDIF and COMTRADE file storage

  • Easy integration with RS232/485 Serial to support either GPS time sync or protocol communications as well as Ethernet and USB communications with protocol support for Modbus, DNP3, FTP and IEC 61850 Edition 2

  • Four available I/O module slots with up to 20 I/O to support multiple customizable I/O applications


  • Power quality alarming/event capture for utility or industrial event investigation/reconciliation, ensuring uptime and predictive maintenance for critical power quality sensitive assets

  • Accurate Class 0.2S energy measurement (demand, time of use) and for utility or industrial Applications

  • High sampling data capture and control in applications such as utility generation or renewables

  • Specialized utility/industrial power quality reporting for standards such as Class A IEC 61000-430 Ed.3, IEC 61000-4-15 flicker, IEC 61000-4-7 harmonics and EN50160


The iSTAT M365 utilizes QDSP setup software to allow for easy initial meter setup, configuration and data visualization.

Time Sync

The iSTAT M365 support multiple types of time synchronization to ensure accuracy and synchronization of various measurements and events to meet standards.

GE Reason RT43x GNSS clocks are recommended to provide accurate time synchronization.

GPS time synchronization (PPS and NMEA)

  • 1pps and serial RS232 communication with NMEA 0183 sentence support

  • The interface is designed as 5 pole pluggable terminal (+5V for receiver supply, 1pps input and standard RS232 communication interface)

IRIG time code B (IRIG-B)

  • Unmodulated (DC 5V level shift) and modulated (1 kHz) serial coded format with support for 1pps, day of year, current year and straight seconds of day as described in standard IRIG-200-04. GE Reason RT43x GNSS clocks recommended for time synchronization

  • Supported serial time code formats are IRIG-B007 and IRIG-B127 Interface for modulated IRIG-B is designed as BNC-F terminal with 600 Ohm input impedance

  • Interface for unmodulated IRIG-B is designed as pluggable terminal

Network time protocol (NTP)

  • Synchronization via Ethernet requires access to a NTP server

Note: NTP can usually maintain time to within tens of milliseconds over the public Internet, but the accuracy depends on infrastructure properties - asymmetry in outgoing and incoming communication delay affects systematic bias. It is recommended that dedicated network rather than public network is used for Synchronization purposes.


The iSTAT M365 supports various communications connections and protocols for easy integration. It is equipped with standard communication port COM1 (Ethernet & USB) and an auxiliary communication port COM2 (RS232/RS485).


iSTAT M365 Brochure

iSTAT M365   Manual

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