1.6.5.4 USERDATA

The USERDATA step reads a known number of bytes and returns these as the user data of the message. USERDATA requires to know the number of bytes to read, from one of these sources:

• A DATALENGTH protocol step appearing above the USERDATA step in the protocol definition.
• A HEXLENGTH protocol step appearing above the USERDATA step in the protocol definition.
• A fixed number of bytes, specified by a number following the USERDATA keyword. If the protocol definition contains a DATALENGTH/HEXLENGTH step and an explicitly given length in the USERDATA step as well, the length specified with the USERDATA step has precedence.