Enterprise Administration > Implementing Windchill ESI > Implementing Windchill ESI in an ORACLE Applications Environment > Understanding Windchill ESI Architecture > Message Logging, Error Handling, and Return Messaging
  
Message Logging, Error Handling, and Return Messaging
The processes for logging, error handling, and return messaging to Windchill PDMLink use the same concepts, but they perform different functions and are implemented differently. The following sections describe the processes and provide a summary of their respective functions.
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Since the Windchill ESI services use the standard Windchill PDMLink logging mechanism, the information in the following sections applies to the EAI software components only.