How to Process HL7 Data Using Talend Data Mapper


As HL7 is the de-facto standard in the health industry, we often get a lot of questions from customers about how to integrate different HL7 standard based systems using Talend and communicate via MLLP (Minimal Lower Layer protocol). In this blog, I will briefly introduce HL7 and its integration with Talend.

What is HL7 Anyway?

Health Level-7 or HL7 refers to a set of international standards for the transfer of clinical and administrative data between software applications used by various healthcare providers. Founded in 1987, Health Level Seven International (HL7) is a not-for-profit, ANSI-accredited standard developing organization dedicated to providing a comprehensive framework and related standards for the exchange, integration, sharing, and retrieval of electronic health information that supports clinical practice and the management, delivery, and evaluation of health services.

HL7 defines a standard for medical applications to exchange data in real-time. The standard defined by HL7 are the only way to ensure communication among different vendors without worrying about message format and communication protocols.

This may imply a ‘Plug and Play’ kind a system though HL7 provides a basic interface. The commercial vendors of healthcare applications bend and customize HL7 to meet the needs of the customer and their systems. This is necessary to accurately exchange patient data. HL7 standard Version 2.3 states that “HL7 provides a common framework for implementing interfaces between disparate vendors”. The standard is intentionally flexible; designed to allow customization but inhibits ‘plug and play’ implementations.

There is a different version of HL7 and version 2.5.1 is considered as healthcare standard to fulfill certification requirement. Most HL7 messaging employs messages that use the 2.3 or 2.3.1 versions of the standard. Newer versions of the standard, including V3, represent only a small portion of real-world usage in interfacing.

At Talend we also have an option to select a version based on our requirement so let’s briefly go through different versions and their specification.

HL7 V2

The HL7 V2 standard was created mostly by clinical interface specialists and was designed to provide a framework in which data could be exchanged between disparate clinical systems.

The V2 standard provides 80 percent of the interface framework, plus the ability to negotiate the remaining 20 percent of needs on an interface-by-interface basis which provides a flexibility for customization. Generally, all 2.X versions are backwards-compatible with earlier versions because the V2 standard allows applications to ignore message elements they do not expect. This means that an older application can receive and process messages from newer applications using newer HL7 versions the messages containing more segments and/or fields will be processed without producing an error.

HL7 V3

The HL7 V3 standard was first released in late 2005, and was strongly influenced by the government and medical information users rather than clinical interface specialists. The V3 version is not backward compatible with V2 versions of the standard, so existing V2 interfaces will not (without considerable modification) can communicate with interfaces using V3.


Fast Health Interoperable Resources (FHIR) is a next generation standards framework that combines the best features of HL7 V2, HL7 V3, and HL7 Clinical Document Architecture (CDA), while leveraging the latest web service technologies. The design of FHIR is based on RESTful web services, and is based on modular components called ‘resources’. FHIR supports both XML and JSON. The first normative edition is expected in 2017.

HL7 with Talend

Talend has added support for the HL7 V2 messaging format in the ‘Talend Data Mapper.  The screenshot below shows all the HL7 versions that can be downloaded into the Talend Studio.  You can download these Talend Data Mapper packages by clicking on Help -> Install Additional Packages… option.  It is advisable to only download and install the HL7 Version that you need.  It is not mandatory to download and install all of them for the feature to work.

Talend component ‘hMap’ from ‘Integration section’ or ‘cMap’ from ‘Routes Section’ needs to configure to process HL7 message.  ‘Talend Data Mapper’ is an intuitive mapping tool which can handle all complex data structures quite elegantly. In the following screenshot, we are mapping a diet plan of a patient and we have mapped messageControldID, patientNumber, PatientIdentifierTypeCode and patientName.

Talend is a very powerful tool to process complex structures and extract useful information It has the capabilities to natively interpret HL7 Message using MLLP Protocol. Talend can produce and consume HL7 messages in real time using ‘Talend Routes’. Please follow step by step guide, How to read HL7 Version 2 Messages with Talend ESB.

With the introduction of Health Level 7 (HL7) integration, Talend has provided a platform where all health service providers can exchange data between different devices and departments. This will help industry to focus more on real-time integrated solutions which will enable information accessibility beyond boundaries.



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