scope:

This guideline is concerned with measures to ensure the interference-free operation of radio communication systems for measurement and automation application as specified in VDI/VDE 2185 Part 1, Section 5. These applications were classified by the ISA as listed in Table 1 (see ISA-SP 100.11). The efforts for the coexistence management can vary according to this classification.

The classification of automation applications listed in Table 1, primarily refers to the function of the application to be considered. Yet, it is possible that an automation application corresponding to its functional range is to be allocated to a higher (less critical) application class, but is vitally important for business processes. In this case it is recommendable to allocate it to a more critical application class, to represent its meaning for the company properly, and to indicate a higher effort to ensure the coexistence.

Further applications ranging from radio bar code readers to voice and video over IP applications can be classified likewise, and can be handled corresponding to this guideline. However, these applications will not explicitly be addressed in the further deliberations.

The considerations are not confined to a specific frequency range like the typically used 2,4-GHz-ISM band. Both, concurrent communication systems and other approved radio applications, e. g. microwave systems for drying or plastics welding, are considered as interferences. Moreover, further interferences might occur due to powerful low frequency electromagnetic fields (e. g. transformers, powerful motors or other EMC influences (see Figure 1). The interference sources to be considered are detailed in Section 6.2.

Even though in this guideline is assumed that actions apply to the location of an enterprise, it should be noted that electromagnetic wave propagation is not localised and that influences from the vicinity cannot be excluded.

It is assumed that a radio system to be considered basically meets the requirements of the automation application and that in particular the limit values for time and error behaviour are observed by planning the communication requirements. As to this process it might be referred to the specifications in the guideline VDI/VDE 2185 Part 1.

The measures described here are to ensure the required performance even in the presence of other radio applications.