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                                  This is the web edition of the original ⮫ AC500-S safety user manual, version 1.3.2. This web edition is provided for quick reference only. The original safety user manual must be used to meet functional safety application requirements.  | 
                           
The main safety function of AC500-S safety PLC is to read safety digital and analog inputs to control the safety digital outputs by the safety logic module (safety CPU) according to a user-defined IEC 61131 application program and configuration.
The AC500-S safety PLC can be used as a "de-energize to trip" (normally energized, NE) system. The safe state of the outputs is defined according to the table below:
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                                  Normally energized, NE  | 
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|---|---|
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                                  Mode according to IEC 61508  | 
                              
                                  High-demand or low-demand  | 
                           
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                                  Safety function  | 
                              
                                  De-energize to trip  | 
                           
| 
                                  Safe state  | 
                              
                                  De-energized outputs  | 
                           
The purpose of AC500-S safety function is to enable a machine or a process (as a system) to achieve with a given SIL (IEC 61508 and IEC 61511), max. SIL (IEC 62061) and PL (ISO 13849-1) a system safe state. An exemplary safety function on the application level, which can be executed by AC500-S in machinery applications, is the emergency stop.
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                        Safety CPU (SM560-S / SM560-S-FD-1 / SM560-S-FD-4)
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                        Safety module with safety input channels (DI581-S, DX581-S and AI581-S)
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                        Safety module with safety output channels (DX581-S)