3.51 User Code Command Class, version 1


The specification states the following -:

These fields contain the user code. Minimum code length is 4 and maximum 10 ASCII digits.

However it seems that some devices (eg RFID readers) are not using ASCII, but are sending binary data. Is this acceptable - it seems to go against the standard?

63 03 00 00 8F D8 C3 0D 01 20 02 80 00 00



We are aware that some RFID tag readers have adopted this non-compliant approach which goes against the specification.

Best regards,


Thanks for the response. Do you anticipate the standard will be updated to make them compliant, or are these devices simply considered as non conforming devices and therefore not approved?

It seems that if you accept this behaviour then the standard should be updated. If not there is a compatibility problem.



Hi Chris,

I really can’t comment on the future, as the command class spec is the result of an expert group, and not up to Sigma Designs alone.

For now the device are non-compliant.

Best regards,