LOGO! Logic Modules Siemens LOGO! Logic Modules allow for the quick implementation of basic automation projects. Designers save space in the control cabinet and can quickly implement functions, such as timer switch, timer relay, counter, and auxiliary relay with LOGO! Logic Modules. Siemens LOGO! Logic Modules comprise eight basic devices for all standard voltages with or without display. The display shows message texts, and the background lighting in white, orange, and red offers many options for visual highlighting, such as for alarm states. All devices in the series have one Ethernet port and can be connected to any previous version. The maximum configuration for one basic device includes 24x digital inputs, 20x digital outputs, and eight analog inputs and outputs.