IP Adapters User Manual

Table Of Contents

Publication 1734-UM016A-EN-P - October 2010

10 Configuration

In row 1, the data is packed on byte boundaries. This is the most efficient data

representation when alignment is not a concern.

In row 2 the data for slot 1 is padded so that slot 2's data began on a Double

Word boundary.

In row 3 every slot takes up the selected size per slot regardless of whether that

module has any data to produce.

This section touches briefly on data alignment. More comprehensive examples

of data alignment are provided in Assembly Structure Examples on page 23.

Troubleshooting Connection Size Errors

If the adapter returns the Invalid Connection Size error in response to a

connection request, it is possible to query the adapter for its calculated size.

This section highlights a technique that can be used to help resolve connection

size errors.

The adapter cannot validate connection sizes until the request to open the

connection is received. It is within that request that the adapter receives the

alignment choice and status election. Based on all the information in the

request and the modules present, the request may be rejected by the adapter

because of a size error.

2 Double Word 19 bytes Double Word 5 bytes

status 8 bytes

slot 1 byte

slot 1 pad

slot 2 int

slot 2 byte

slot 3 byte

run / idle 4 bytes

slot 3 byte

3 6 bytes per slot 26 bytes 1 byte per slot 7 bytes

status 8 bytes

slot 1 6 bytes

slot 2 6 bytes

slot 3 6 bytes

run /idle 4 bytes

slot 1 byte

slot 2 byte

slot 3 byte

T → O alignment T → O size O → T alignment O → T size