Digital modules 
  8.7 SM 326; F-DO 10 x DC 24V/2A PP (6ES7326-2BF10-0AB0) 
Fail-safe signal modules 
Installation and Operating Manual, 01/2010, A5E00085586-10 
165 
8.7.2 SM 326; F-DO 10 x DC 24V/2A PP applications 
Selecting the application 
The figure below helps you to select an application based on availability and fail-safe 
operation requirements. The next pages provide information on the module wiring for a 
specific application, and on the parameters to set in 
STEP 7
 using the 
S7 Distributed Safety
 
or 
S7 F Systems
 optional package. 
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Figure 8-54  Application Selection - SM 326; F-DO 10 x DC 24V/2A PP 
Test pulses of the light and dark test 
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Figure 8-55  Light test, if assigned 
The typical break between two test pulses is 0.5 seconds. There can be another test pulse 
① in between. The gap between the first test pulse and the additional test pulse is one 
module cycle.