QCN: Cancel query
This page lists the structures and trigger events QCN defines, taken from the standard. The written commentary that theADT page carries has not been written for QCN.
Recognising QCN messages
QCN announces itself in MSH-9 like this:
QCN^J01^QCN_J01- MSH-9.1
QCNmessage code: what kind of message this is - MSH-9.2
J01trigger event: what happened in the real world: cancel query/acknowledge message - MSH-9.3
QCN_J01message structure: which segments to expect, and in what order
How to use these specifications explains MSH-9 in full, with a worked example.
Message structures
QCN takes 1 structure.
QCN_J01: cancel query/acknowledge message
2 different trigger events send this structure:
The segments below are the same for all 2. HL7 varies the meaning, not the shape: there is no separate QCN_J02 layout. What changes is MSH-9, which tells the receiver which of the 2 happened and therefore what to do with the message.
You must always send: MSH, QID. Everything else is optional, or required only inside a group you chose to send.
| Segment | Name | OPT | Cardinality |
|---|---|---|---|
| MSH | R | 1..1 | |
| SFT | O | 0..* | |
| QID | R | 1..1 |
Trigger events
The trigger event is the real-world thing that made the message get sent. QCN defines 2.
| Event | Name | Structure |
|---|---|---|
| J01 | cancel query/acknowledge message | QCN_J01 |
| J02 | cancel subscription/acknowledge message | QCN_J01 |