MSH Segments
Contents
The MSH segment is the MeSsage Header segment. Every HL7 message starts with an MSH segment. This segment contains the following information that’s relevant to an ACK message:
| Location | Information | Description |
|---|---|---|
| MSH.3 – MSH.6 | Sending Application (MSH.3), Sending Facility (MSH.4), Receiving Application (MSH.5), Receiving Facility (MSH.6) | Indicates what application generated the message, and what facility generated the message. |
| MSH.10 | Message Control ID | Unique ID for the message being sent. This is used by the receiving system to distinguish between messages being sent to them. |
| MSH.12 | Version ID | Allows the sending system to indicate which version of the HL7 standard that their message complies with. |
For the inbound parsing of each message you want to acknowledge, it is important to store the message control ID and possibly other parameters like the sender, version, etc.
Continue: MSA Segments