Fail-Safe Modules   
7.7 4 F-DO DC24V/2A PROFIsafe digital electronic module 
  ET 200S Distributed I/O System - Fail-Safe Modules 
172  Installation and Operating Manual, 08/2008, A5E00103686-07 
7.7.5  Diagnostic Functions of the EM 4 F-DO DC24V/2 A PROFIsafe 
Behavior in case of supply voltage failure 
In the case of a voltage dip in the external auxiliary voltage, the SF LED lights up, the 
module is passivated.  
With the subsequent supply recovery (level must remain above the specified value for at 
least 1 minute (refer to the technical specifications: voltages, currents, electrical potentials)) 
the SF LED goes out again, the module remains passivated. The SF LED flashes if there are 
no other errors, until the error is acknowledged. 
Diagnostic functions   
The table below provides an overview of the diagnostic functions of the EM 4 F-
DO DC24V/2A PROFIsafe. The diagnostic functions are assigned either to one channel or to 
the entire module. 
Table 7- 36  Diagnostic functions of the EM 4 F-DO DC24V/2A PROFIsafe 
Diagnostic Function*  Fault 
Number 
LED  Effective Range of 
Diagnostics 
Can be 
Assigned 
Parameter
s 
Short circuit   1
H
  SF  Channel  No 
Overload   4
H
  SF  Channel  No 
Overtemperature   5
H
  SF  Module  No 
Wire break   6
H
  SF  Channel  Yes 
Internal error   9
H
  SF  Module  No 
Parameter assignment error   10
H
  SF  Module  No 
Sensor voltage or load voltage missing    11
H
  SF  Module  No 
Communication error   13
H
  SF  Module  No 
Safety-related shutdown   19
H
  SF  Channel  No 
*: specially for F-modules; display in 
STEP 7
, see "Channel-Specific Diagnostics, Fault Types of Fail-
Safe Modules" table  
 
 
WARNING 
 
Before acknowledging the short-circuit diagnosis, remedy the respective error and validate 
your safety function. In this case, follow the steps described in chapter "
Reactions to Faults 
(Page 
41)".