Parameters for the HL7 to HL7 DFDL pattern

Source
Pattern parameter Default Description
Source type Generic This parameter defines the type of source application. The parameter is used to select the GenericHL7Input node in the Receiver flow.
Source facility This parameter defines the source facility that is included in error messages, notifications, and standard journaling messages.
Source identifier Source application This parameter defines an identifier that is used to describe the source in error messages, notifications, and standard journaling messages.
Connection details localhost:1111 This parameter defines the TCP/IP connection for the source application in the form hostname:port
Timeout waiting for data (seconds) 60 This parameter defines the length of time that the node listens on a connection for more data after the first byte of data has arrived. You can specify any length of time in seconds. The default is 60 seconds. When the specified time has been exceeded, all available data is sent to the Failure terminal.
Leading MLLP byte 0B This parameter defines the leading MLLP byte that must be trimmed off the front of the HL7 record.
Trailing MLLP bytes 1C0D This parameter defines the trailing MLLP bytes that are used as an HL7 record delimiter. These trailing MLLP bytes are removed by the TCPIPServerInput node. They are also added by the TCPIPClientOutput node which returns HL7 acknowledgments.
Consecutive error limit 0 This parameter defines the maximum number of consecutive errors that are tolerated before closing the network connection. Any non-positive number is treated as an infinite value, and the connection is not ended if there are consecutive faults.

The connection is always ended if the message does not contain the correct leading MLLP byte.

Destinations
Pattern parameter Default Description
Number of destinations 1 This parameter defines the number of destinations to which source messages are distributed.
Part 1 This parameter defines which part of a multi-part pattern is currently being configured.

For more information about configuring multipart pattern instances, see Running the pattern.

Destination 1 parameters
Pattern parameter Default Description
Destination type Generic This parameter defines the type of the destination application. The parameter is used to select the GenericHL7Output node in the Sender flow.
Identifier Destination 1 This parameter defines the identity of a destination. This identity is used in error, report, and notification messages related to a destination.
Destination facility This parameter defines the facility of a destination. This facility is used in error, report, and notification messages related to a destination.
Sequencing action None If the option to apply sequence numbers is selected in the Receiver flow, this parameter determines how sequencing is applied for a destination. Valid values are:
  • None: Messages are processed in the order in which they arrive.
  • Strict: Messages cannot be processed out of order. If a message is missed, all other messages are held until it arrives.
  • Lax: In general, messages are processed in order. However, if a message has not arrived within a given time period, other messages are processed. If the missing message arrives after the timeout, the missing message is inserted into the stream.
Sequencing timeout (seconds) This parameter defines the time in seconds that the flow of messages waits for a message that does not arrive in the correct sequence. After this time, messages continue to flow. If the missing messages arrive later, the missing messages are inserted into the stream.
Message filtering Cleared This parameter determines whether the messages that are sent to a destination are filtered. When this parameter is selected the message filtering table becomes visible and filtering criteria can be entered.

Filtering ensures that only messages where the values from the MSH-9 (Message Type field) for Message Code and Trigger Event match Filter 1 and Filter 2 values.

If more complex filtering is required, you can modify the ESQL code following the same approach.

Segment filtering Cleared This parameter determines, for a destination, which segments are copied from the source message. When this parameter is selected, the segment filtering table becomes visible and filtering criteria can be entered.
Connection details localhost:2222 This parameter defines the TCP/IP connection for a destination in the form hostname:port
Standard MLLP Selected This parameter determines whether a default configuration for TCP/IP and MLLP is used. The default configuration has the following values:
  • Timeout: 60 seconds
  • Leading MLLP byte: 0B
  • Delimiter: Not applicable
  • Retry limit: 3
  • Log retries: true
  • Validation: false

If the parameter is not selected, the parameter group to define non-standard values becomes visible.

Message filters for destination 1
This table defines the set of messages that are passed to the destination application.
Table parameter Mandatory Default Description
Code Yes   This parameter defines a message code that a message must match if it is to be passed to the destination.
Event Yes   This parameter defines the message events that are used to filter messages. If all message events are allowed, enter an asterisk (*).
Segment filters for destination 1
This table defines the set of segments that are passed to the destination application.
Table parameter Mandatory Default Description
Segment Yes   This parameter defines the segment codes that are used to filter segments. If the three letter segment code matches any entry in the segment filters table, the segment is excluded from the outgoing message.
Destination 1 communications
Pattern parameter Default Description
Timeout (seconds) 60 This parameter defines the timeout for a destination in seconds.
Leading MLLP byte 0B This parameter defines the leading MLLP byte, which is added to outgoing records.
Trailing MLLP bytes 1C0D This parameter defines what the delimiter is. This value must be in hexadecimal.
Retry limit 3 This parameter defines the number of times a Sender flow attempts to deliver an HL7 message to the destination application.
Log retry Selected This parameter determines whether each attempt to deliver a message is logged.
Validation None This parameter determines whether the message is validated against the HL7 message set.
Options
Pattern parameter Default Description
Source feed Selected This parameter determines whether a copy of the source message is generated. The Publish parameter determines whether the source feed is written to the queue instance.SRCF or published to the topic PatternId/Receiver/Source
Sequence numbers Arrival based This parameter determines how message sequence numbers are set for the sequencing behavior that is defined by the sequencing parameter for each destination. Valid values are:
  • No sequencing
  • Arrival based: Sequence numbers are assigned according to the order of arrival at the node.
  • Content based: Sequence numbers are assigned from the sequence number found within the MSH header.
Send acknowledgment Selected This parameter determines whether the sending application expects a standard ACK or NACK response.
Journaling Standard This parameter determines the journaling options. Valid values are:
  • None: No journaling. This option can also be used if the pattern user wants to use a source feed to carry out journaling to their own requirements.
  • Standard: A copy of each message is produced with standard header information defined by the pattern. This copy is published to the topic PatternId/Receiver/Journal or written to the journal queue as determined by the Publish parameter.
Canonical feed Cleared This parameter determines whether a copy of the message in canonical form is generated. If selected, the Publish parameter determines whether this copy of the message is sent to the PatternId.CAN queue or to the topic PatternId/Canonical
Report remainders Selected This parameter determines whether remainder fields are reported.

If an incoming message has segments that are not modeled in the HL7 message set, remainder fields are found.

If this parameter is selected, the Publish parameter determines whether messages with remainder fields are sent to the PatternId.REM queue or published.

This action is particularly useful during the development of integration between HL7 applications.

Check duplicates Selected This parameter determines whether duplicate messages are detected, as determined by the unique message identifier in the HL7 MSH header.

If duplicates are detected, the following action is taken:

  • If the message is received within a timeout period, the message is not processed but the same ACK that was sent for the original message is returned to the sender.
  • After a time period has expired, any duplicate messages are processed as usual.
Publish Publish This parameter determines whether journal messages, remainder messages, and other reports are published or written to queues.
Separate sequence queues Cleared This parameter determines whether separate queues are used for each pattern instance to store messages during sequencing. By default, all messages stored for sequencing on a broker are held on a single system queue.

If this parameter is selected, a configurable service is defined for this pattern instance. This configurable service is used to define the internal queues that are used by the Resequence nodes in the Sender flows.

Duplicate processing
Pattern parameter Default Description
Report duplicates Selected This parameter determines whether duplicate messages that arrive within the specified time generate an error notification message.
Expiry of identifier messages (seconds) 86400 This parameter defines (in seconds) how long identifier messages are kept before expiry. After this time period, duplicates are not recognised and are processed as usual. The default equates to 24 hours.
General
Pattern parameter Default Description
Description HL7 Pattern This parameter defines the purpose of the flow that is generated, and can include any details that you require.
Queue prefix This parameter defines a string that you want to prefix to the queue names. The standard queues are created with this prefix and a standard set of suffixes.

If this parameter is left blank, the pattern instance name is processed to remove non-alphanumeric characters and then it is used as the queue prefix.

Flow prefix This parameter defines a string that is added to the start of the name of each main message flow in a generated pattern instance. This string helps to identify the components of the pattern instance in reports and monitoring.

If this parameter is left blank, the pattern instance name is processed to remove non-alphanumeric characters and then it is used as the flow prefix.

Generate scripts Selected This parameter determines whether an MQSC deployment script is generated.
Trace file name tracefile.txt This parameter defines the file name, including the path, to which trace output is sent. If no path is provided, the trace file is written into the bin directory of your broker installation.

All the pattern parameters are listed with their default values. Where no default is indicated, the default value is an empty string.

Back to the HL7 to HL7 DFDL pattern specification