Understanding and making the key decisions at the start of an RFID project makes all the difference between success and failure. These are our top 7 agenda items when discussing RFID feasibility.
Active or Passive tags?
Active tags emit a stronger signal, and do so without activation from an RFID reader. They continuously ‘chirp’ their identity. However they are battery-powered and cost more than passive tags. Passive tags tend to be smaller than active tags, and have a longer lifespan. If a tag only needs to respond at the time when it is read, then this would be a strong point in favour of selecting passive tags. Active tags should only be selected over passive tags if there is a compelling reason for doing so. In our experience, passive tags will provide an ideal solution for automated inventory control, but without the cost of active tags.
Required read range
The distance at which tags need to be read influences not only the choice of tag, but also crucially the choice of reader too. Some key questions to consider are: How far will the reader be from the tag that it is reading? Will tags have different orientations when they are read? What are the spatial dimensions of the area where read coverage is needed? The choice of hardware must be proven to achieve the read requirements that are set out by the answers to these questions. With RFID, there is no single ‘best’ solution, and particular care is therefore needed in choosing the right equipment.
Selection of tags
The primary consideration when selecting tags is to find the optimal balance between tag size and required read range. As a general rule, the larger the tag the greater the read range. Next, consider whether there is likely to be interference from any electromagnetic source. Today, tags are optimised to work either on metal, off metal, or near to metal. Consider also whether the tags will be subject to physical contact or impact. Are any special coatings needed for the tags?
Attaching tags to assets
Think carefully about how and where tags will be attached. Obviously a secure attachment, which does not affect the integrity of the asset to which it is attached, is essential.
Think through how tags will be programmed with unique information, such as an identification number. Tag commissioning should ideally be done away from the final asset location, and not after the tag has been fitted to the asset itself.
Once the system has been designed, is it essential that it is thoroughly tested in the actual operating environment where it will eventually be used. Sources of interference in the actual operating environment can give rise to test results that are significantly different from those achieved in a different location, such as a design office for example.
Research new applications for RFID
RFID technology is evolving continuously at the moment. New, innovative devices and applications are being released all the time. It is very worthwhile keeping up to date with these, since any one of them could be ideally suited to the requirements of your project.