April 8, 2015 Leave a comment
At this point it is pretty clear that RFID is a fairly simple identification solution that involves a tag, antenna, and processor. The tag holds the information that is critical to the application. That information could be a very brief identifying number, sometimes called a license plate, and usually consists of 4 to 12 Bytes of data. Or, the application may require the tag to hold all the information about the product being manufactured such as build data, process data, or lineage data. In this case, there are tags with up to 128 Kilobytes of available storage. The scenarios above help to answer the question: “when do I use IO-Link RFID?”
Simply put, IO-Link makes life on the manufacturing floor much easier. It eliminates the mess in the cabinet, it is plug and play, it allows connection to any major controller, etc. etc. etc. So, why not just do away with everything not IO-Link and call it a day? For RFID there is 1 major question that needs to be answered to determine whether or not IO-Link is the right solution: How much data needs to be read from the tag?
IO-link specializes in transferring smaller amounts of data. When required to transfer large amounts the speed is greatly reduced. Here is a very simple way to look at it: IO-Link RFID comes in two different versions- 10Bytes or 32Bytes. The 10 Bytes or 32 Bytes refer to the size of the buffer or container that transfers the data. Imagine this as two semi-trucks carrying a load in a trailer (buffer). Of course, the 32 Byte trailer can carry a larger load (Data) than the 10Byte trailer. Therefore, we can conclude that the 10Byte trailer has to make more trips to carry larger amounts of data. More trips take more time therefore slowing down the process. If there are only 8Bytes of data that need to be read from the tag then the 10Byte version is fine, but if there are 28 bytes then it makes sense to us the 32 Byte version. However, as mentioned above there are applications where the tag may hold up to 8KB, 32KB, or even 128KB of data and IO-Link should not be considered. As a general rule IO-link should not be used to read anything over 96 Bytes due to speed being greatly reduced.
Need For Speed?
As a rule of thumb it takes about .2 seconds for IO-Link RFID readers to read 16Bytes of data and about .5 seconds to read 96Bytes. Reading anything above 96Bytes increases the read time dramatically. As a comparison, the latest and greatest Balluff RFID processor, the BIS V can read 256Bytes of data in about .2 seconds.
Ultimately, the amount of data that needs to be read from the tag and the time required to read that data should be the deciding factors of whether or not IO-Link RFID is right for the job or not.