Which of the following is an example of a modular controller?

In the context of PLCs, a modular controller refers to a type of programmable logic controller that can accommodate additional modules, allowing for increased flexibility and expandability based on the application's needs. The chosen answer, the 1769-L32E, is indeed a modular controller designed by Allen-Bradley, part of the CompactLogix family.

This controller supports the addition of various input and output modules, communication modules, and other extension modules, enhancing the capability of the system to meet specific automation requirements. Its modular design enables users to customize the configuration by selecting the appropriate I/O, communication, and specialty modules, making it suitable for a wide range of industrial applications.

The other options, while they might be part of the same family of controllers, do not share the same level of modularity or may represent fixed configurations without the same range of expansion capabilities as the 1769-L32E. Therefore, the 1769-L32E stands out as the correct answer when identifying an example of a modular controller.