Introduction to Address Elements and Address Information Blocks

Generic AIB Format

An Address Information Block (AIB) is used to address system objects, such as spans and channels. An AIB has a header, followed by one or more Address Elements. An Address Element is a group of data bytes that represent specific address information.

Address Method

Use this field to specify one of two methods for the AIB:

Individual or Range

0x00 - Individual AEs

The Individual AEs method treats each Address Element as a single entity. Use the Individual AEs method to address the following:

• A single component, such as a channel or a slot

• Multiple independent components that are not in a range, such as two channels in a Connect message, where Address
Element 1 defines Channel A and Address Element 2 defines Channel B.

0x01 - Range

Use this method to define the two Address Elements that are the starting and ending entities in a range.

For example, you use this method in an Inpulsing Parameters Configure message to configure a range of channels, where Address Element 1 defines the starting channel and Address Element 2 defines the ending channel.

Important! The field is contained in the AIB in the API messages not in the AE tables in this chapter.

Number of Address Elements

This field indicates the number of Address Elements in the AIB.

An Address Element is a group of data bytes that describe an address. The number of data bytes in an Address Element varies, depending on the address element type.

Important! The field is contained in the AIB in the API messages not in the AE tables in this chapter.

Address Element (AE) Type

This field specifies the Address Element (AE) type. An AIB can contain several AEs. PPL Components use Address Elements in various PPL Messages.

If you use the Individual AEs Addressing Method, you can insert multiple AEs, of different types, into a single AIB.

If you use the Range Addressing Method, you can insert two, and only two, Address Elements, and they must both be of the same Address Type.

Data Length

This field indicates the number of data bytes in the AE immediately following this byte. If an AE contains no data, the value of this field is 0x00.

Data[0]. . . Data[n]

The number of Address Elements in an AIB depends on the message, address type, and addressing requirements.

For example, the table below shows an AIB that has one Address Element, which in turn contains two data fields.

Using AIBs

To use AIBs in a message, perform the following steps:

1. Determine the required address method and address type. Each message shows the AIBs that are supported by that message. The AIBs are presented in tables similar to the one above.
Remember to build flexibility into your applications to allow for future expansion of the API, including new AIB Address Methods and Types, new addressing requirements, and new functionality.

2. Insert the information, as defined in the table, into the AIB section of the message.The addressing requirements of the message determine the values for the Address Method and Number of Address Elements fields. The object being addressed determines the address data fields.

The table below shows how an AIB is inserted into an API message. The address data fields are bytes 12–13.

Example 1

The table below shows the ARP Cache Query message, with an AIB inside it. You would refer to the Slot AE for its format.

Example 2 - Individual AEs Method – Two Address Elements

The table below shows an AIB that uses the Individual AEs address method and that has two Address Elements. This AIB would be used in the Connect message, where:

• Address Element 1 defines Channel A

• Address Element 2 defines Channel B

Example 2 - Range Method

The table below shows an example of an AIB that uses the Range address method. This AIB would be used in configuration messages to address a range of channels or other components, where:

• Address Element 1 defines the Starting Channel

• Address Element 2 defines the Ending Channel.

A range must contain two and only two Address Elements.

Important! To address a single channel using the range method, enter the same channel as both the starting and ending channel.