BizTalk HL7 Accelerator Enhanced vs Deferred mode

Question

I am unsure of the difference between the deferred mode and enhanced mode. Both send two acknowledgements; 1 for accept and one for application acknowledgements, aside from that what is the difference in behavior?

Answer 1

The only difference is when MSH15 and MSH16 are not there in message, Deferred mode only generates AA (application acknowledgment) acknowledgment while enhanced mode generates CA (Commit Accept) acknowledgment. Deferred mode is present due to backward compatibility with version v2.1. It basically implements Delayed Acknowledgment Mode which was specified in HL7 V2.1 standard and then was deprecated from V2.2 onwards. This is similar to enhanced mode but implemented in a different way. One difference you will find in deferred mode generated acknowledgment is "D" added to MSA5 field.