Controller unit

A controller unit, comprising:

• a base unit having a slot;
• a module that includes a printed circuit board and that is mounted in the slot of the base unit;
• a pair of male and female connectors, one being included in the base unit and the other being included in the module in order to electrically connect the base unit to the module;
• and
• a turning support configuration of a fitting type that allows the module to be turned with respect to the base unit in order to join the pair of connectors together by turning of the module with respect to the base unit;
• wherein
• the base unit includes a projection and the module includes a plurality of recesses such that the projection engages with a recess of the plurality of recesses before the pair of connectors are connected together,
• the recess and the projection are located at positions separated from positions of the pair of connectors in the base unit and the module, and a distance between the positions of the pair of connectors and the positions of the recess and the projection varies depending on a type of combination of the modules that cannot be wrongly joined to the slots,
• the module includes a casing and the plurality of recesses are a plurality of holes in the casing, and
• the printed circuit board is mounted in the casing and an edge of the printed circuit board includes a recessed shape at a position corresponding to a position of one hole of the plurality of holes in the casing.