Issues on using wireless modules in machinery
In the European Union (EU) it is mandatory that radio equipment meets the 'essential requirements' of the Radio and Telecommunications Terminal Equipment Directive 1999/5/EC (R&TTE). This will be new territory for machinery manufacturers embedding wireless modules into their equipment for the first time. Neil Dyson of TUV SUD Product Service offers this guidance.
The rising trend for manufacturers to add wireless modules into products, beyond the more traditional market of laptops and mobile phones, means that they are now being included in everything from domestic fridges to industrial machinery. By using such a wide number of wireless technologies in close proximity to each other, this is starting to create a safety and product reliability issue as devices increasingly experience interference from each other, as well as from other electronic equipment. Consequently, we are seeing a significant increase in the number of non-compliant products coming into our laboratories.
In order to reduce both costs and time to market for new equipment, many machinery manufacturers are relying on the use of wireless modules which already meet some or all of the R&TTE essential requirements. However, once these modules are integrated into another product, this changes the regulatory requirements as the host machine falls within the scope of the R&TTE Directive.
The R&TTE Compliance Association has issued some guidance on the use of wireless modules (Technical Guidance Note on the R&TTED compliance requirements for a Radio Module and the Final Product that integrates a Radio Module, May 2013). This has been updated several times over the last few years, so the situation is not static and is subject to change.
In a nutshell, this guidance states that when an R&TTE compliant module is integrated into a final host product, no further radio testing is necessary on the host product, provided the module is integrated in accordance with the manufacturer's instructions. But, the host product must always meet the other essential requirements of the Directive, namely the safety and EMC aspects. However, integrating a wireless module is not always as straightforward as it may seem. The most common method of demonstrating compliance with the R&TTE essential requirements is by using 'Harmonised Standards'. These are written and published under an EU mandate, and provide a 'presumption of conformity' (or compliance), provided they are applied in full.
However, Harmonised Standards are always evolving, which means they have what is effectively an expiry date as they become superseded by more up-to-date standards, which may well have different requirements. Machinery manufacturers may therefore need to perform a gap analysis between the two sets of standards in order to bring their products up to speed with the latest requirements.
The USA and Canada have formal approval processes in place, so the routes to compliance are reasonably clear compared to Europe. However, the Federal Communications Commission (FCC) rules can be difficult to understand. So, for those wishing to export products to North America, it may be prudent to seek guidance from an authorised test laboratory or from an FCC-designated Telecommunications Certification Body.
When all FCC requirements are met and the device is certified, the FCC grant will state that the device has modular approval. Provided the conditions of the grant are adhered to, there should be no further testing or certification required for the intentional radiator part of the host machine, but a label should be displayed stating that an approved wireless module is contained within the host.
With different rules applying to the global marketplace, manufacturers are advised to follow some basic guidelines when integrating wireless modules into products. For European compliance, ensure that the wireless module you are integrating is fully compliant with the latest Harmonised Standards and is integrated in accordance with the manufacturer's supplied instructions. While the module manufacturer should be aware of the integration rules, as a minimum the final/host machinery manufacturer should check the module's Declaration of Conformity to ensure that it lists Harmonised Standards which are in date.
It is also important to have access to the module manufacturer's technical file in case the host machinery manufacturer is asked to prove compliance by a country's market surveillance authority.
Remember that products containing wireless transmitters must also comply with national radio regulations no matter where in the world they are used, a product containing a wireless transmitter must not be shipped to a non-EU country without checking the regulations. For USA and Canada, host machinery manufacturers should check the conditions of the module grant and ensure that the product is not breaking those conditions. Once again, follow the module manufacturer's guidance on integration.
It is clear that a key reason for non-compliance of final host machines containing wireless modules is that while these modules are compliant as an independent unit, once they are integrated into another product that changes the requirements.
Machinery manufacturers are assuming that because the wireless module is compliant, that they do not have to do any more tests to declare against different standards. This is wrong. In any country, the market surveillance authorities can come down hard on manufacturers that supply non-compliant equipment to the market and ignorance of the rules is no excuse.
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