This custom block performs a digital write operation that enables the user to control Arduino boards. The class uses a Python module called "pyfirmata" to be able to change the states of the ports that are connected to the Arduino board. The module allows for various operations to be performed by connecting to the Arduino board via serial ports.

This custom block allows the user to change the state of digital pins. The user enters the digital pin numbers into the "Port Number List" input socket and the digital pin states into the "Port State List" input socket. For instance, the user enters the digital pin numbers 2, 3, and 4 into the "Port Number List" input socket and the corresponding states (e.g. 1 or 0) into the "Port State List" input socket. The block takes this information and changes the states of the corresponding digital pins.

Additionally, the block allows the user to select the serial port that their Arduino board is connected to. The user can select the serial port through the block parameters.

This custom block can be used in various applications such as robotics, automation systems, and sensor networks where Arduino boards need to be controlled.