Preface 
SCALANCE M874, M876 
Operating Instructions, 08/2018, C79000-G8976-C331-08 
5 
Siemens provides products and solutions with industrial security functions that support the 
secure operation of plants, systems, machines and networks. 
In order to protect plants, systems, machines and networks against cyber threats, it is 
necessary to implement – and continuously maintain – a holistic, state-of-the-art industrial 
security concept. Siemens’ products and solutions constitute one element of such a concept. 
Customers are responsible for preventing unauthorized access to their plants, systems, 
machines and networks. Such systems, machines and components should only be 
connected to an enterprise network or the internet if and to the extent such a connection is 
necessary and only when appropriate security measures (e.g. firewalls and/or network 
segmentation) are in place. 
For additional information on industrial security measures that may be implemented, please 
visit 
Link: (https://www.siemens.com/industrialsecurity) 
Siemens’ products and solutions undergo continuous development to make them more 
secure. Siemens strongly recommends that product updates are applied as soon as they are 
available and that the latest product versions are used. Use of product versions that are no 
longer supported, and failure to apply the latest updates may increase customers’ exposure 
to cyber threats. 
To stay informed about product updates, subscribe to the Siemens Industrial Security RSS 
Feed under 
Link: (https://www.siemens.com/industrialsecurity) 
The products are low in pollutants, can be recycled and meet the requirements of the WEEE 
directive 2012/19/EU for the disposal of electrical and electronic equipment. 
Do not dispose of the products at public disposal sites. 
For environmentally friendly recycling and the disposal of your old device contact a certified 
disposal company for electronic scrap or your Siemens contact (Product return 
(https://support.industry.siemens.com/cs/ww/en/view/109479891)). 
Note the different national regulations. 
The following and possibly other names not identified by the registered trademark sign 
®
 are 
registered trademarks of Siemens AG: 
SCALANCE, SINEMA, KEY-PLUG, C-PLUG