This automatic transfer switch controller provides flexible source configuration, comprehensive electrical monitoring, protection functions, and remote communication for reliable power transfer and genset management. Key features Configurable system types: Source 1 and Source 2 can each be set as Mains or Generator, supporting all combinations. Backlit 128x64 LCD with optional Chinese and English display and pushbutton operation for clear local status and simple setup. Measures and displays twoway threephase voltage and frequency, threephase current, active power, apparent power, and power factor. Protection and alarms: overcurrent alarm; overvoltage and undervoltage protection; loss of phase; reverse phase sequence; overfrequency and underfrequency protection. Operation modes: Automatic and Manual. Manual mode allows forced close or open of the switch. Testing modes: Genset test can run in onload or offload mode. Closing output can be configured as pulsed intervals or continuous output. Automatic reclosing function included. Scheduler and logging: Realtime clock, monthly or weekly scheduling, trial runs onload or offload, and circular event log storing the last 99 events. Dualgenerator support: Can control two generators in rotation with independently set run times and crank rest intervals. Security: All parameters adjustable on site with twolevel password protection to restrict access to authorized staff only. Power and input tolerance: Wide DC supply range 8 V to 35 V, able to tolerate up to 80 V DC for short transients. Optional HWS560 module for DC 12 V output from AC input 85 V to 560 V. AC input terminals provide wide spacing and accept up to 625 V. Communication: Isolated RS485 interface with ModBus protocol for remote control, remote measurement, and remote communication. Benefits and problem solving Flexible source assignment simplifies integration into existing installations where either or both sources may be mains or generator. Continuous electrical monitoring and protective functions reduce the risk of equipment damage from voltage irregularities, phase loss, or frequency deviations. Automatic and manual control modes plus configurable closing output behavior accommodate both automated transfer and supervised interventions during testing or maintenance. Scheduler, event logging, and RTC enable planned testing and traceable history for maintenance and compliance records. Dualgenerator cycling and timed crank/rest settings support balanced generator use and easier maintenance planning. RS485 ModBus support enables integration with building management systems and remote supervision, reducing the need for onsite staff. Compatibility and installation notes Applicable to ATS arrangements with one neutral position, two neutral positions, changeover configurations, and systems with two isolated neutral lines for mains and generator. Accepts wide AC and DC inputs and includes isolated communication for robust field connections. All configuration and protection settings are programmable on site through the LCD and pushbutton interface. Typical applications Commercial and industrial buildings requiring reliable automatic switching between mains and backup generators, with scheduled generator testing. Generator farms and rental fleets that need timed rotation of multiple gensets and configurable crank and run cycles. Facilities with remote monitoring, such as data centers, telecom sites, and utilities, that require ModBuscompatible control and event logging for maintenance and system integration. This controller combines flexible configuration, comprehensive monitoring and protection, scheduled testing and rotation capabilities, and standard ModBus communication for reliable ATS management in diverse installations.