An RFID tag can be encoded with two different encoding methods within TracerPlus and ClearStream RFID: ASCII and hexadecimal. ASCII is a character encoding standard that is used to display text in digital equipment, including computers and mobile devices. It has the capability to display the full English alphabet, the numbers 0 – 9, and some basic punctuation symbols. Because of this capability, ASCII can be used to encode human-readable RFID tags; when the tag is read and decoded by TracerPlus or ClearStream RFID, it will show up as plain text.
Hexadecimal (hex) is a number system that is popularly used in many computing applications. When tags are encoded using hex, the tag value is generally used as a simple identifier and not a human readable string.
RFID tag identifiers are always WRITTEN as hexadecimal values to the actual tag, but they can be ENCODED as ASCII values or hexadecimal values when read using TracerPlus or ClearStream RFID. If encoded as ASCII values, every ASCII character will be converted to a byte, which will be written as two hex characters. Most RFID tags have a 24 byte limit, this means that an ASCII encoded RFID tag can only contain 12 characters. If encoded as hex values, but the application is set to convert them to ASCII, it is possible to see what appears to be garbage data when the tag is read. This is because when the hex data is decoded it may be decoded to an ASCII character outside of the range of the standard human readable characters.
So what should you choose? If you need human-readable tag IDs, make sure to encode your tags in ASCII mode. If you don’t need human-readable tags and just need a simple unique identifier, use hexadecimal.