I wrote a quick classmethod in my custom FunctionSet class to test your observation and found that I can use the full mnemonic property path name, for example:

ClassMethod GetControlID(pMsg As EnsLib.HL7.Message) As %String
{
    // Also works with "MSH:10"
    Return pMsg.GetValueAt("MSH:MessageControlID")
}

Example from a rule (I used Document, but HL7 also works):

And the resulting trace from the Visual Trace:

I'm thinking that your inbound messages might not have the DocCategory (ex. "2.3.1") and DocName (ex. "ADT_A01") properties set ... ?

Looking through the HL7 2.5 OML_O21 structure as supplied by InterSystems, you'll find that there's a nested PIDgrpgrp() under ORCgrp().OBRgrp() that has a subordinate ORCgrp(). It looks like the parse is attempting to match on the required OBR segment in the nested PIDgrpgrp().ORCgrp().

You have a couple of options ... both of which require a custom schema to match your message. The first is to make the OBR segment in the PIDGrpgrp().ORCgrp() optional; the second is to remove the PIDgrpgrp() grouping entirely in the custom schema.

EDIT: The first option doesn't work since the ORC matches on the optional ORC segment in the nested PIDgrpgrp.ORCgrp(), which makes it attempt to match on the required PIDgrpgrp.ORCgrp().OBXgrp().

The NTE segment is commonly used for plain-text "notes" containing descriptive data that doesn't conform to the structured format used for most other data in HL7 messages. It could certainly be used for the storage of base64-encoded binary data, and the likely candidate for that would be the NTE:3 Comment field.

If the base64 content is less than ~3.5MB in size, it can be assigned directly to that field in a DTL or using the SetValueAt() method of the message object (Note: the HL7 specification does not define a maximum length for the Comment field, but there are considerations for IRIS storage that need to be handled appropriately). If larger than 3.5MB, it must be stored using the StoreFieldStreamRaw() method of the EnsLib.HL7.Message object (there is also a StoreFieldStreamBase64() method but it's not applicable if your data is already in base64 format). If you must use the StoreFieldStreamRaw() method, note that it must be the last method called against the NTE segment as it makes the segment immutable.

The recipient of the ORL_O22 message must be informed of this atypical use of the NTE segment so that it can be handled appropriately.

You can use the "*" shorthand for obtaining a count of the number of repeating segments (or fields, or groups) in a when clause. Anything greater than 0 evaluates to "true," so adding a Not() around the expression negates that:

Note: The original reply had Document.DocTypeName rather than Document.Name as the first part of the condition expression. The DocTypeName property refers to the message structure, not the actual message trigger event. That's in the Name property.

If the content of the field that contains the base64-encoded PDF is greater than the maximum string size in IRIS, it will be stored as a stream.

I've written a custom function that will extract the full content of a message containing such a value; it was originally created to support fetching large HL7 messages in HL7 Spy. You can download it here: http://www.hl7spy.com/downloads/HICG_HL7.xml. I've been asked to add it to the OEX repository, but I just haven't gotten around to that yet ...

I'm not sure how the SQL Editor in the management console will handle a query that uses that function, though. It will likely cause some interesting behavior 😉

The specific SQL function in that class is HICG.GetBigMsg(<messagebodyid>).

I"m assuming you're talking about HL7 here ...

InterSystems does a bit of magic in the background to display the Message Body fields in the message viewer, and it's not immediately available to you. However, I've written a custom SQL function that fetches the field at the supplied path (you'll need supply the path as its defined by the Schema/DocType of the message).

Example:

SELECT TOP 100 head.ID As ID,
        {fn RIGHT(%EXTERNAL(head.TimeCreated),999 )} As TimeCreated,
        head.SessionId As Session,
        head.Status As Status,
        head.SourceConfigName As Source,
        head.TargetConfigName As Target,
        HICG.GetMsg(head.MessageBodyId,'MSH:9') As MessageType
    FROM
        %IGNOREINDEX Ens.MessageHeader.SessionId Ens.MessageHeader head
    WHERE
        head.SessionId = head.%ID
        AND head.MessageBodyClassname = 'EnsLib.HL7.Message'
        AND head.SourceConfigName = 'SourceBusinessHostName'
    ORDER BY
        head.ID Desc

You can download the class here: http://www.hl7spy.com/downloads/HICG_HL7.xml

I don't know of any other attributes, and increasing logging may turn up something but hasn't proved useful in my experience.

If your servers are reporting occasional disconnect errors, that's not necessarily a network issue, or even something to worry about. The mirror members may report disconnections due to things like snapshots/backups where one or more hosts are momentarily suspended by the hypervisor in a virtualized environment, or updates to the OS that might stop/start services as part of the update process. It's important to remember, though, that the arbiter is designed to operate optimally in a low-latency, same network, same data center scenario. If your mirrored hosts are spread across a WAN, you're asking for errors.

As part of the encryption negotiation process, there's an exchange of supported cypher suites between the client and server. If there's no match, no connection can be established. No need to force a specific cypher site; all available should be presented by the client during connection negotiation.

If upgrading to a current version of HealthShare/Health Connect is not an option, you could script the transfers outside of the production (batch/powershell/Python/Perl script running under Windows' Scheduler or called from ObjectScript in a Scheduled Task via $ZF(-100) ) and then use a File service/operation to pick them up for processing or drop them off for delivery.

I've worked with a number of integration solutions over the last few decades and not a single one of them would work with this vendor's perverse interpretation of HL7 communications out-of-the-box.

Health Connect / HealthShare can accommodate pretty much anything if you're willing to dip your toes into ObjectScript and write custom services and operations. But the OOB classes won't handle the vendor's requirements without subclassing/extending.

Acknowledgements

There are certainly variances in the types of acknowledgements received and even cases where acknowledgements are received out-of-band (Sunrise Clinical Manager, I'm looking at you). I've even seen implementations where multiple HL7 messages are sent, streamed in a batch, with envelope characters wrapped around the whole batch rather than the individual messages. In that case no ACK was expected. I wrote a custom service to handle that one.

Fundamentally, Health Connect is a request/response messaging system and violating that design presents some interesting challenges. Receiving the ACKs back asynchronously over the same connection is theoretically possible, but I wouldn't encourage the vendor to work that way ... every single future customer will be problematic for them.

Message Control IDs

I've never seen an engine that increments the message control ID automatically, although it's something that can be coded/customized in multiple solutions. The message control ID is defined by the sending application, not the middleware; setting the MSH:10 in the engine is usually an extraordinary measure.

HL7.org defines it as such:

This field contains a number or other identifier that uniquely identifies the message.

If the same message was re-sent with a different MSH:10 value, it would not be uniquely identified. In my opinion, at least.

Depends on your platform (although that may have changed since the last time I configured an LDAP setup).

With Caché/IRIS running on *nix variants, the only option is STARTTLS, which is encrypted but uses the "standard" port 389. With Windows, I believe "LDAP over SSL" (aka LDAPS) is also an option, on port 686 by default.

Both will require that whatever certificate is served is valid for the load balancer. This is usually accomplished via a certificate Subject Alternative Name value.

Not with this code, no. I interpreted your original request literally, assuming that you wanted to send the email directly from within a custom service.

If you wish to have an Email operation in the production that handles the delivery of messages from routing rules, that's a bit more work to create, but in the end more versatile and easier to support.

If you don't care about having an operation, you could create a class that extends Ens.Rule.FunctionSet that wraps the original class in such a  way that you can send email from a rule:
 

Class User.Util.FunctionSet Extends Ens.Rule.FunctionSet
{
ClassMethod SendEmail(pToAddr As %String, pSubject As %String, pMessageBody As %String) As %Status
{
	Set tMail=##class(User.Mail).%New()
	Set tSC = tMail.Send(pToAddr, pSubject, pMessageBody)
}
}

You could then call it from a rule (the assign simply lets you call it and optionally do something with the returned status):