Structured Fields › Format of Structured Fields

Format of Structured Fields

The format of a structured field is as follows:

• Bytes 00 to 01

  Specifies the field key—a hexadecimal value that defines the item of information described by this field.

• Bytes 02 to 03

  Specifies the subfield count—a hexadecimal count of the number of subfields within this structured field.

• Bytes 04 to 05

  Specifies the subfield length—the hexadecimal length of the following subfield.

• Bytes 06 to nn

  Specifies the subfield data.

Subfield length and subfield data are repeated according to the number specified in subfield count.

Example:

The following diagram shows structured field X'0011'. This field is used to define a user's name. This name can be associated with the user ID so that the person can be identified when they log on.

Structured field X'0011' consists of:

• Field key of X'0011'
• Subfield count of X'0001' (1 subfield)
• Subfield length of X'0014' (20 characters)
• Subfield data of JOHN SMITH (padded with blanks on the right to make up the 20 characters).

  

The following diagram shows structured field X'0023'. This too has a single subfield with a value of Y and is used to indicate that the user is entitled to access the System Support Services function.

Updating a Structured Field

For examples of how to update structured fields, including those with multiple subfields, see the description of the &SECCALL verb in the Network Control Language Reference.

Structured Field Error Conditions

Error conditions can occur during the processing of a set of structured fields due to one of the following reasons:

• The omission of a structured field.
• An invalid value has been specified in a structured field.

If an error does occur during structured field processing, then:

• The structured field is assigned its default value.
• An error message is written to the log.

If error conditions occur, a user might not have all the expected privileges when logged on to the system.

Structured Field Sequences

Your product region processes structured fields in the order in which they appear. While most structured fields are independent of other fields, certain fields must be processed before others. Where such dependencies exist, they are noted in the description of the fields concerned.