Serializing IDocs
You serialize IDocs in the following cases:
● If you want the Integration Server to process the corresponding IDoc XML messages in the same sequence that it receives them from the IDoc adapter at the inbound channel.
● If you want the receiver to receive the IDocs in the same sequence that the IDoc adapter sends them at the Integration Server outbound channel.

The sequence at the Integration Server inbound or outbound channel can only be guaranteed if only IDocs are processed, and not if different protocols (for example, IDocs and proxies) are processed together.
Do not confuse the serializing of IDocs using the IDoc adapter with ALE serialization.
More information:
ALE
Serialization
● The quality of service EOIO (Exactly Once In Order) must be specified in the message header.
More
information:
Quality of
Service
● The receiver system or the sender system must be based on AS Java 6.40 or higher.
If this is not the case, the quality of service is automatically changed to EO for compatibility reasons and the message is processed accordingly.
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1. If you want the Integration Server to process the IDoc XML messages created by the IDoc adapter in the same sequence that the IDocs are sent by your application, proceed as follows:
○ Enter a queue name in your application. You can use 16 alphanumeric characters. The prefix SAP_ALE_ is then added.
The IDoc adapter checks the prefix and replaces it with the prefix of the corresponding Integration Server inbound queue (for example, XBQI0000).
2. If you want the receiver to receive the IDocs in the same sequence that they are sent by the Integration Server using the IDoc adapter, proceed as follows:
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○ In the communication channel, select the check box Queue Processing for the receiver.
The IDoc adapter replaces the prefix of the outbound queue (XBQO) with the prefix SAP_ALE_.
You can display the individual messages in the qRFC monitor of the outbound queue. To do this, do one of the following:
■ Use the queue ID in the list of displayed messages in the monitor for processed XML messages.
Further
information:
Monitor for Processed
XML Messages
■ Use the transaction ID in the list of displayed XML messages in the IDoc adapter.
More information: Displaying XML Messages
■ Call transaction qRFC Monitor (Outbound Queue) (SMQ1).
■ To navigate directly to the display of messages in the IDoc adapter, double-click the transaction ID of a message in the outbound queue.

To do this, you must have registered the IDX_SHOW_MESSAGE display program for the outbound queue in the qRFC administration (transaction SMQE) beforehand.
In both cases, the function module IDOC_INBOUND_IN_QUEUEis called, which enables EOIO processing of the messages. The processing sequence is determined by the sequence of the function module calls.

Unlike the other function modules (interface versions from the communication channel), with this function module you have to transfer segment types in the data records rather than segment names.