iNTERFACEWARE™ Inc.

Anatomy of an ACK/NACK Message

Generating an ACK or NACK message requires the definition of a generic mechanism to extract the standard MSH (MeSsage Header) fields from each incoming message, and use them to populate the required fields in the ACK message.

The following diagram labels the important parts of an ACK/NACK message:

You can see that it consists of two segments called MSH and MSA.