2. TheReceiver sends the message to the Forwarder.
3. TheForwarder sends the message to the receiving External System.
4. Thereceiving External System sends an ACK to the Forwarder.
5. TheForwarder receives the ACK from the External and forwards it on to the Receiver.
6. TheReceiver then forwards the ACK, with an MSH - 5, value “F” indicating that it is the
receivingExternal System’s ACK,to the Sender.
Inthe Receiver role, the HL7 RA is congured for inbound, and the inbound Collaboration is
usedwith the parameter Sends App Ack set to true. In the Forwarder role, the RA is set to
outbound,the parameter Forward External Acks to eGate , is set to true, and the outbound
Collaborationis selected.
Thisconguration table presents the necessary parameters used to congure the Adapter to
assumethe Delayed ACK roles
TABLE1 Adapter Delayed ACKC onguration
Role Direction SendsAppAck Property ForwardExternalAcks
Sender Out True N/A
Receiver In True N/A
Forwarder Out N/A True
Anexample of the receiver role is provided in the prjHL7Inbound sample Project. The
prjHL7OutboundProject provides a sample implementation of the Forwarder role.
Inbound Functionality
Theinbound TCP/IP HL7 Adapter Project, prjHL7Inbound, provides a sample
implementationof an inbound ow using the Adapter. It can be congured for standard
inboundmode or for forward message mode.

InboundAdapter Data Flow

Theinbound TCP/IP HL7 Adapter Project receives HL7 messages from an external system,
sendsan acknowledgement of the message to the external, provides sequence numbering,
writesthe HL7 message to a JMS data queue, and also writes the HL7 message and ACK to a
JMSjournal queue. Any error messages and NAKs are sent to a JMS error queue.
TheHL7 data is processed so all the elds in the MSH segment of the message are stored in an
internalstructure to generate an HL7 response. Non-HL7 data, including HL7
acknowledgments,automatically generate warnings in the Adapter’slog le and send an HL7
NAKto the external system.
SunAdapterfor TCP/IP HL7 Overview
SunAdapterfor TCP/IP HL7 User's Guide •October 200914