Components You can find information about diagnostic options in the following manuals and 
sections:
DP/PA Coupler Operating instructions 
DP/PA couplers, active field distributor, DP/PA Link and 
Y Link
Diagnostics by means of LED displays
● LED displays of the IM 157
● LED displays of the DP/PA coupler
● LED displays of the Y coupler
Y-Link Information under DP/PA Coupler
FF Link Operating instructions 
SIMATIC; FF Link
 bus link
Compact FF Link Operating instructions 
SIMATIC; Compact FF Link
 bus link
AFD 
(use on fieldbus - 
PROFIBUS PA or 
FOUNDATION Field‐
bus)
Manual 
SIMATIC;
SIMATIC NET; PROFIBUS PA
● Diagnostics by means of LED displays
● Diagnostic messages for electronic modules
AFDiS Operating instructions 
DP/PA couplers, active field distributor, DP/PA Link and 
Y Link
● LED displays of the AFDiS active field distributor
AFDiSD
(Use on fieldbus - 
PROFIBUS PA)
Operating instructions 
DP/PA coupler, active field distributor, DP/PA Link and 
Y Link
Product information 
SIMATIC; Bus Link; 
Supplements to the operating instructions FF Link 03/2015
Operating instructions 
SIMATIC; Bus Link; 
Extended fieldbus diagnostics in PROFIBUS PA
● LED displays of the field distributor
AFS (use on fieldbus - 
PROFIBUS PA or 
FOUNDATION Field‐
bus)
Manual 
SIMATIC;
SIMATIC NET; PROFIBUS PA
● Diagnostics by means of LED displays
● Diagnostic messages for electronic modules
Diagnostic repeaters Manual 
SIMATIC; 
Diagnostic Repeater for PROFIBUS DP
● LED diagnostics
Switch for Ethernet Operating instructions 
SIMATIC NET;
Industrial Ethernet Switches SCALANCE X-400
● LED
Commissioning manual
 SIMATIC NET; Industrial Ethernet, SCALANCE X-100 
and SCALANCE X-200 Product Line
● SCALANCE X<…> displays (SCALANCE X208 displays, for example)
Status LEDs for PROFINET IO and PROFIBUS DP
Comparison of LEDs for diagnostics
Diagnostics in PCS 7
8.17 Diagnostics for hardware displays
Service Support and Diagnostics (V8.2)
106 Service Manual, 03/2016, A5E36200111-AA