Here is the next field in the Data Frame, the Control Field. It consists of 6-bits, the first two of which are reserved. The other 4-bits in the Control Field are the Data Length Code (DLC), which tells how much information is contained in the Data Field. The DLC bits – DLC3, DLC2, DLC1, and DLC0 – indicate the number of data bytes in the data field, according to the coding scheme shown in the table. Valid sizes are 0 to 8 bytes, as indicated. Codes that do not appear in the table are reserved.

