AM3270 Management Programming Manual

ELEMENTS OF SPI MESSAGES FOR THE SUBSYSTEMS

Tokens

The AM3270 subsystem uses tokens for parameters in commands,

responses to commands, and elements of event messages. Each

token has a token code and token value associated with it. A

token code is an identifying tag that programs refer to by name,

and a token value is a data item that programs also refer to by

name. The token code has two parts: a token type that specifies

the data type and length of the token value, and a token number

that uniquely identifies the token for the subsystem. See "Token

Types" in this section for a list of the token types used in the

AM3270 subsystem.

The actual token value can be in one of the following forms:

• A single field, such as an integer or a character string

• A fixed structure

• An extensible structure

Tokens that have a token value that is a single field or a

fixed structure are called simple tokens. Tokens that have a

token value that is an extensible structure are called extensible

structured tokens.

Simple Tokens

Simple tokens are tokens whose values are single fields or fixed

structures. The token codes for the simple tokens used by the

AM3270 subsystem are represented by symbolic names of the form

subsys

-TKN-

name

, where

subsys

is a three-character subsystem

abbreviation and

name

identifies the token code. For example,

the token code ZEMS-TKN-LDEV identifies a simple token that

contains a logical device number. They are considered simple

tokens because you do not need a map to decode or build the

structure.

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