A modular device, including a base unit with a plurality of module sockets and a number of modules that can be detachably connected to the module socket as well as a control unit for the connected modules, and the module sockets have manually actuatable locking devices for the modules. The locking devices include a manually actuated actuating device, which can be pivoted around a pivot axis from a first end position through an intermediate position into a second end position and which locks the module in the first end position and release the module in the second end position, and have a detector for detecting at least the first end position and the intermediate position of the actuating device.
