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Siemens AG
Entry type: Product note Entry ID: 4202341, Entry date: 02/25/1997

Digital Output Modules 451-4UA14 and 454-4UA14 - New Revision Level 2

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Concerns products with the catalog Nos.:                                    


6ES5 451-4UA14    451 dig. outp. module for S5-135/155U                     

6ES5 454-4UA14    454 dig. outp. module for S5-135/155U                     


_Reason for the change:_                                                    


In the case of unfavourable voltage fluctuations of the 24 V load           

voltage, the short-circuit indication of the 6ES5 451-4UA14 and             

6ES5 454-4UA14 digital output modules may be wrong. The red short-          

circuit LED will light up briefly, although there is no short circuit.      


In isolated cases there will even be a permanent short-circuit              

LED signal as well as a short-circuit output signal at the front            

connector of the module.                                                    


Nevertheless, proper functioning of the module and of the short-            

circuit protection are assured.                                             




The above problem has been eliminated with revision level 2 of the          

modules. If the fault occurs with one of your modules, please speak         

to your SIMATIC contact at your Siemens office about an upgrade.            




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