Fail-Safe Modules 
  7.6 EM 4 F-DI/3 F-DO DC24V PROFIsafe digital electronic module 
ET 200S Distributed I/O System - Fail-Safe Modules 
Installation and Operating Manual, 08/2008, A5E00103686-07 
155 
7.6.6  Output applications of EM 4 F-DI/3 F-DO DC24V PROFIsafe 
Application 1: Wiring a load to each digital output 
Each of the three fail-safe digital outputs consists of one DOx P P-switch and one DOx M M-
switch. You connect the load between P and M-switches. The two switches are always 
activated so that voltage is applied to the load. 
The wiring is carried out on an appropriate terminal module. 
30(
)',)'2
/ 0
/ 0
3 0
'2 '2 '2 '2 '2 '2
. . .
3 0 3 0
 
Figure 7-45  Wiring Diagram EM 4 F-DI/3 F-DO DC24V - Output Circuit 
 
 
Note 
In order to achieve SIL2/Category 3/PLd with this wiring, you must install a suitably-qualified 
actuator, for example in accordance with IEC 60947. 
 
Application 2: Wiring loads to L+ and M at each digital output  
Not allowed.