The front panel EXT connector of your PLC is designed for connecting optional DIN rail modules, or custom development boards (see breadboard adapter accessory). When the connector is not in use, it can be covered with a protective cap.

Temperature sensor for the built-in UPS Battery charger. It monitors the temperature of the battery and allows Temperature Controlled Charging.

The charger uses the sensor data and user-defined charging parameters as a starting point from which the charging algorithms calculate the actual values to be applied to the DACs to support functions such as temperature compensated charge voltages and currents, maximum power point tracking, charger soft starting, etc.

FLEXBOOL is an open source, free of license limitations, industrial-grade PLC family, based on ESP32 MCU and fully compatible with Arduino IDE. With its excellent communication capabilities and wide I/O standards support, the FLEXBOOL PLC can operate as a complete stand-alone system, as well as a part of another system. It allows easy building of control and monitoring systems where the reliable measurements and control abilities can be easily combined with an impressive user interface. 

FLEXBOOL PLC family is based on the ESP32 dual-core 32-bit Xtensa LX6 MCU (240 MHz Clock frequency, 520 KB of SRAM, 448 KB of ROM and 16 MB of FLASH).

FLEXBOOL is fully compatible with ARDUINO IDE. All Arduino math and logic functions as well as many Arduino libraries can be used in your code.

Our FLEXBOOL PB Series PLC models support up to 32 Power Bus extenders, connected in a daisy chain to a 2-Wire bus (Power + Data) with a total length up to 500 meters.

FLEXBOOL PLC has an internal Real Time Clock/Calendar that allows you to create Alarm/Event Logs, keep track of operating hours, set reminders for the system user, and initiate various periodic processes like defrost, bearing lubrication, water treatment, tank ventilation, etc.

FLEXBOOL RTC is supplied by an internal capacitor backup that provides reliable RTC operation in case of a power break for up to 60 days.

FLEXBOOL PLC provides 10/100Mbs Ethernet communication based on the Microchip physical tranciever LAN8720 and ESP32 MAC layer. There are many useful examples posted on our web site, like setting up a static IP Address, or obtaining an IP Address from the router, pinging another network address, arranging a SD Card hosted Web Server, and Modbus TCP communication with other devices.

Complying with the industry standard for long-distance communication, the RS485 port of FLEXBOOL PLC provides anti-interference and reliable operation. It features reduced slew-rate drivers that minimize EMI and reduce reflections caused by improperly terminated cables, allowing error-free transmission up to 500kbps. The AutoDirection feature provides faster switching speeds, no contact bounce, better reliability, and better electrical isolation. 

Each FLEXBOOL PLCmodel is equipped with a SD Memory Card (included), that can be used for storing system data, Alarm/Event Logs, display images, web interface scripts, etc.
There many examples posted on our web site including reading/writing data to the card, creating/deleting files and folders, and building a SD Card stored web server / User Interface.

All FLEXBOOL PLC models have a full-color (64k) TFT with 240x240px resolution, and 1.3'' size. In combination with the panel buttons on the left side of the display, it can be used for a variety of purposes, including browsing the controller's menus, real time monitoring of analog and digital input/output states, and changing user-configurable set points.

FLEXBOOL PLC models Lite and 3 have an integrated, user-configurable, smart battery charger with UPS functionality. When a battery is connected to the controller, it is constantly charged and monitored.
In case of any power break, it will provide unbreakable power supply to the controller.

FLEXBOOL PLC provides 2.4GHz WiFi connection 802.11b/g/n. It features WMM, 4 × virtual Wi-Fi interfaces, simultaneous support for infrastructure station, SoftAP, and promiscuous modes.

The FLEXBOOL PLC comes with Bluetooth Low Energy and Bluetooth Classic. 

The programming/debug port of the FLEXBOOL PLC is USB-C type, which is more compact than its predecessors and reversible in connectivity.

All FLEXBOOL Inputs are Over-voltage and Over-current protected. DO, AO, PWM and DC Outputs are over-current protected. Supply terminals are Over-voltage and reverse-polarity protected. 

FLEXBOOL PLC provides reliable hardware Self-Test functionality. Depending on your project, the hardware check can be performed only at startUp, or periodically during the controller operation. 

We provide many free code examples, including UART, RS485, Modbus RTU, Modbus TCP, Power Bus communication, integration with Siemens & Delta PLC, Iridium, NodeRed, Grafana interfaces, Nextion & Delta HMI, etc.