Diagnostics data of signal modules 
  B.3 Channel -specific diagnostics data, starting at byte 8 
S7-300 Automation System Module data 
Manual,  08/2006, A5E00105505-04 
B-5 
B.3  B.3 Channel-specific diagnostics data, starting at byte 8 
Introduction 
Data record 1 contains the channel-specific diagnostic data, starting at bytes 8 to 15. The 
figures below show the assignment of the diagnostics byte of a module-specific channel or 
channel group. General rule: An error is indicated by a logic "1" at the relevant bit. 
For information on possible error causes and troubleshooting routines, refer to the chapter 
"Module diagnostics."  
Digital input channel of SM 321; DI 16 x DC 24 V; with hardware/diagnostics interrupts 
&RQILJXULQJSDUDPHWHUDVVLJQPHQWHUURU
*URXQGIDXOW
6KRUWFLUFXLWWR/
6KRUWFLUFXLWWR0
:LUHEUHDN
6HQVRUVXSSO\PLVVLQJ
 
Figure B-4  Diagnostics byte for a digital input channel of SM 321; DI 16 x DC 24 V 
Digital output channel of SM 322; DO 8 x DC 24 V/0.5 A; with diagnostics interrupt 
&RQILJXULQJSDUDPHWHUDVVLJQPHQWHUURU
*URXQGIDXOW
6KRUWFLUFXLWWR/
6KRUWFLUFXLWWR0
:LUHEUHDN
([WHUQDODX[LOLDU\VXSSO\PLVVLQJ
2YHUWHPSHUDWXUH
 
Figure B-5  Diagnostics byte for a digital output channel of SM 322; DO 8 x DC 24 V/0.5 A