A programmable logic controller (PLC) assembly includes a bottom housing with a base, a first plurality of elongate alignment features extending from the bottom housing transverse to the base, and a first connection feature. The PLC assembly includes a central processing unit with a circuit board and at least two receptacles therethrough configured to engage and slide along at least two of the first plurality of alignment features. The at least two of the first plurality of alignment features are positioned asymmetrically with respect to the base. The PLC assembly includes an upper housing with a second connection feature configured to slidably couple with the first connection feature and a second plurality of elongate alignment features configured to slidably engage at least two of the first plurality of alignment features, which are positioned asymmetrically with respect to the base.