Industrial Shields Spartan Arduino PLC is an open-type controller that operates at a 12V to 24V input voltage range (VDC). This controller offers communication using I2C by a primary-secondary connection that connects up to 127 modules. The Spartan connector features 16x of both digital and analog inputs/outputs and provides a clock speed of up to 16MHz. Industrial Shields Spartan Arduino PLC is available in a 100mm x 45mm x 115mm package and offers a USB port, a Modbus (RTU), an I2C, and an SPI for communication.