Installation   
5.6 Fitting an extender 
  SCALANCE XM-400 
52  Operating Instructions, 09/2018, C79000-G8976-C306-08 
Fitting and removing an extender 
Fitting an extender 
 
To fit an extender, follow the steps below: 
1.  Remove the cover of the expansion interface on the basic device. 
2.  Fit the two devices together so that the two centering pins are accommodated by the 
opposing openings 
①. 
3.  Press the devices together until they are flush. 
The centering pins click audibly into place. The locking device is automatically pressed up 
briefly as this happens.