Layer

A Layer is the top-level container of widgets in an ARINC 661 Definition File.

Layer properties

The main property of a Layer is its Layer ID. A Layer in a Definition File is specified by:

• The Application ID of its Definition File
• The Layer ID of the Layer

All Layers in a Definition File have the same Application ID. Note that it is forbidden for two Layers to share the same (Application ID, Layer ID) pair in all the server.

Layer ID

A Layer is identified by:

• The Application ID of its Definition File
• The Layer ID

Note that the ARINC 661 runtime communication does not exchange the application ID, which means that the resolution of the Layer concerned by a block in the runtime Buffer is implementation dependant.

Widgets tree

The Layer is a container which contains a "tree" of widgets, called "widgets tree". Leafs in the tree are terminal widgets (such as for example an A661_PUSH_BUTTON, whereas container widgets (such as A661_PANEL) may contain children.

Runtime communication

The Buffer exchanged in the Client => Server communication include the Layer ID for all Layer, but not the Application ID. This means that there should be some network mechanism to be able to identify the Application ID for a communication Channel. The J661 project has two ways to manage this:

• If there is only one Layer for one Layer ID in all the Server, the Server knows the Layer which is the destination of an ARINC 661 Buffer
• Else the network configuration allows to specify for a Channel which Layer to address for one Layer ID found in the Buffer