Series 651  MAINTENANCE 
 
605451EC  Edition 2014-07-10  85/
 
7.2.4  Retrofit / replacement procedure 
Top view on control and actuating unit with panel removed: 
 
 
 
 
All boards have a fixed position into control and actuating unit. It is not possible to fit a 
board in other position as shown in picture above! Do not try out other positions, 
which maybe destroy the socket of boards! 
 
 
Master board 
 
 
 
 
Option board 
 
 
Interface board