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Entry type: Product note Entry ID: 4328236, Entry date: 02/04/1997

S7-300, New High-Speed I/O Modules with Diagnostics

  • Entry
  • Associated product(s)

Concerns products with the Catalog Nos.:                                    


6ES7 321-7BH00-0AB0   SM 321, 16x24 V DC, with interrupt                    

6ES7 322-8BF00-0AB0   SM 322, 8x24 V DC/0.5 A, isolated                     



_SM 321-7BH digital input module_                                           


The SM 321-7BH is a high-speed interrupt module with 16 DI/24 V DC. The     

input delay can be parameterized to 0.1ms; 0.5ms; 3ms; 10ms. The minimum    

response time that can be achieved with the S7-300 is thus approx. 1ms.     


The new module permits detection of high-speed events as well as diagnos-   

tics of the inputs and of the module itself.                                

The following can be monitored:                                             

-  Rising edge of an input signal (generates process interrupt in OB 40).   

-  Falling edge of an input signal (generates process interrupt in OB 40).  

-  Transducer supply missing (generates diagnostic interrupt in OB 82).     

-  Internal diagnostics of the module (generates diagnostic interrupt in    

   OB 82).                                                                  


_SM 322-8BF digital output module_                                          


The SM 322-8BF is a digital output module with 8 DO, 24 V DC/ 0.5A and      

diagnostics. The outputs are suitable for a redundant configuration, i.e.   

there are 2 connections per channel. One channel is wired conventionally    

and the other one has a series diode for redundant operation. The output    

current cannot be increased by connecting the outputs in parallel. This     

module now permits diagnostics of 24 V DC circuits with S7-300/ET 200M.     


The module has extensive diagnostics features, as well as substitute value  

switching in the case of a fault. There is a group signal with LED display  

as well as a channel signal with evaluation possibility. The following      

events can be diagnosed:                                                    

- Short circuit to M.                                                       

- Short circuit to P.                                                       

- Wire breakage.                                                            

- Load voltage missing.                                                     

- Module diagnostics: No aux. voltage, watchdog, EPROM/RAM fault.           


Technical data:                                                             


Outputs:      8 DO                                                          

Voltage:      24 V DC                                                       

Current:      0.5 A                                                         

Diagnostics:  Short circuit, wire breakage, load voltage, module.           

Substitute value switching option.                                          


Your SIMATIC contact at your local Siemens office will answer any further   

questions you may have.                                                     




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