BECKHOFF CX2500­0031 - Manual (Page 13)

Mounting and wiring
Incorrect installation positions
The CX20x0 system must not be operated vertically on the top­hat rail. A vertical position would lead to
insufficient CPU ventilation, since the ventilation openings are located on the top and bottom of the housing.
Installation of the system on its side would also lead to inadequate ventilation.
CX2500­0031 13 Version 1.1