#1 Simple Example or Explanation?

[Ed Murphy]

Hi...I've been asked to looking into doing some
processing of data that will be retrieved using an HL7
2.3 compliant connection. I'd comfortable with Perl and
other similar protocols, but the documentation I've
been able to find on HL7 hasn't been very helpful.

From what I understand, I need to

1. Create a connection to the remote HL7 system
2. Create a Request message
3. Populate the Request message with data
4. Send the request the the remote HL7 compliant system
4. Process the response

I can see that I am making a connection to the remote
system but from there I'm lost.

The main problem I'm having is with steps 2 and 3. Is
there a simple example of how a request is built? Are
the segment values what control what data is requested?
Will a response be one record or a bunch of records?
I'm thinking this is like a database in that I issue a
request with the data criteria and the response I get
back is the data that satisfies the criteria...am I
thinking about this the wrong way?

Any help that you can provide would be most welcome.

Regards,
Ed