EPICS Qt Getting Started

Download and Build
qtcreator Build


There are number of different types of EPICS Qt users, and getting started is different for each type. EPICS Qt users can broadly be divided into the following categories (note a user may “belong” to more than one category):

Download and Build

The following items are needed to build EPICS Qt.


Information regarding downloading and building EPICS may be found at EPICS Home at Argonne and also at the new EPICS Controls web site. Alternatively speak to your local EPICS expert.

EPICS Qt has successfully been built and tested using, but not limited to, EPICS base versions, 3.15.6 and 7.0.3. For PV Access functionality, EPICS 7 is required.


Qt is available from the https://www.qt.io/ web page. Versions 4.6, 4.8.4, 5.6, 5.7, 5.9, 5.10 and 5.13 have been successfully used at the Australian Synchrotron. Version 4.8.4 is the earliest version we now actively support. For new users I would recommend Qt 5.10. For Archive Appliance users, Qt5 is required.

After installation and adding the appropriate directory/folder to your PATH variable you should be able to do something similar to the following on Linux:

$ export PATH=${PATH}:/opt/Qt5.10/5.10.0/gcc_64/bin
$ qmake -v
QMake version 3.1
Using Qt version 5.10.0 in /opt/Qt5.10/5.10.0/gcc_64/lib
$ uic -v
uic 5.10.0
$ moc -v
moc 5.10.0

and to this on Windows:

C:\>qmake -v
QMake version 3.0
Using Qt version 5.6.1 in C:/qt5/5.6/mingw49_32/lib
C:\>uic -v
uic 5.6.1
C:\>moc -v
moc 5.6.1


The selected version of QWT must be compatible with your version of Qt. For Qt 5.6 or later we use QWT version 6.1.3. For Qt 5.13 we found 6.1.3 uses a number of deprecated function and QWT 6.1.4 is recommended.

For Linux users, a suitable version of QWT may be available via your distribution’s package manager (e.g. yum, apt). If not, it is available from http://qwt.sourceforge.net/.


From EPICS Qt version 3.7.1 on-wards, the low level Channel Access handling has been dropped from the EPICS Qt framework and has been replaced by the ACAI package. This is available from https://github.com/andrewstarritt/acai

git clone https://github.com/andrewstarritt/acai.git

Building ACAI is straight forward. After downloading, cd to the <top> directory, modify the line the EPICS_BASE= definition in the configure/RELEASE (or configure\RELEASE on windows) file to point to your local EPICS base location and then call make.

Once ACAI has been build, and with a suitable PATH environment variable defined, you should be able to do similar to the following:

$ export PATH=${PATH}:/epics/acai/bin/linux-x86_64
$ acai_monitor -v
ACAI 1.5.4 using EPICS 3.15.5


C:\> acai_monitor -v
ACAI 1.5.4 using EPICS

acai_monitor is a test/demo program that uses the ACAI and EPICS libraries, however the program itself is not used by EPICS Qt.

For MSVC users, please use ACAI version 1.5.3 or later.

Google Protocol Buffers

This is only required if building the Archive Appliance interface. Please see the Archive Appliance page for details. For Linux users using the yum package manager, this can be achieved by (drop the sudo if running as root):

sudo yum install -y protobuf

For Windows users, there is some info in Archive Appliance.

FFMpeg Support

This is only required if building FFMpeg Support. For Linux users using the yum package manager, this can be achieved by (drop the sudo if running as root) first installing the nux repo if needs be. For CentOS 7 this can be done like this:

sudo rpm --import http://li.nux.ro/download/nux/RPM-GPG-KEY-nux.ro
sudo rpm -Uvh \

And to install the ffmpeg packages themselves please run:

sudo yum install -y  ffmpeg-devel  ffmpeg-libs


The EPICS Qt source code and documentation is available from the EPICS Qt website at GitHub. The EPICS Qt site provides a number of repositories. In order to build the EPICS Qt libraries and the QEGui display manager, you will need to download the following:

Modify RELEASE files

The commands shown here illustrate downloading and building EPICS Qt in the directory /home/user/qtepics. This is just for the purposes of providing example commands. You are free to down load and install anywhere on your system. Replace the green part of the path in the examples below to suit your own environment.

Note: This instructions are currently Linux-centric, however Windows users should have no trouble translating these to the Windows equivalent.

Modify /home/user/qtepics/qeframework/configure/RELEASE file such that:

QE_FRAMEWORK=<span style='color:#00c000'>/home/user/qtepics</span>/qeframework<br>
ACAI=__a reference your ACAI diretory__
EPICS_BASE=__a reference your EPICS base diretory__

If you are using EPICS 7 together with PV Access, and wish to decompress images compressed using the Area Detector Codec plugin, the modify /home/user/qtepics/qeframework/configure/RELEASE file such that:

ADSUPPORT=__a reference your ADSUPPORT module__

If not required, please remove the ADSUPPORT definition.

Modify /home/user/qtepics/qegui/configure/RELEASE file such that:

QE_FRAMEWORK=<span style='color:#00c000'>/home/user/qtepics</span>/qeframework<br>
EPICS_BASE=__a reference your EPICS base diretory__

Environment Variables

Define EPICS_HOST_ARCH (e.g. export EPICS_HOST_ARCH=linux-x86_64)

Define QWT_INCLUDE_PATH (e.g. export QWT_INCLUDE_PATH=/usr/include/qwt)

Define QWT_ROOT to the qwt location (e.g. C:/qwt-6.1.3/ on Windows or
export QWT_ROOT=’/usr/local/qwt-6.1.3’ on Linux if not in default location)

Optional: Define QE_FFMPEG if mpeg streaming is required (on Windows, this must point to the FFMPEG directory; on Linux just being defined is sufficient).

Optional: Define QE_ARCHAPPL_SUPPORT=YES to include Archive Appliance support.

Optional: Define PROTOBUF_INCLUDE_PATH. When Archive Appliance selected, location of the protobuf header files (if not already in tool chain search path).

Optional: Define PROTOBUF_LIB_DIR. When Archive Appliance selected, location of the protobuf library files (if not already in tool chain search path).

Optional: Define QE_CAQTDM if integration of PSI’s caQtDM into QEGui is required. If you want caQtDM integrated, download and build it and define the environment variable QE_CAQTDM to point to the caQtDM_Project directory.

Optional - deprecated: Defining QE_TARGER_DIR forces libraries, header files and binaries to be built/installed into the nominated directory. This is not recommended and included for legacy purposes only. Note: If this environment variable is defined, you must modify the QE_FRAMEWORK definitions in the configure/RELEASE files to be consistent with this variable.

More details are available at environment_variables.html.


When building in headless, i.e. command line, mode, the qmake program is invoked to generate a Makefile based on the project .pro file. Ensure that your PATH environment variable results in required version of qmake being available. For some versions of Qt 4, the qmake program is known as qmake-qt4. In this case it will be necessary to “fake” it, e.g.:

cd ${HOME}/bin
ln -s /usr/bin/qmake-qt4 qmake

or something similar.

Also, qmake is called without the -spec option defined and relies on the default spec file (e.g. linux-g++) being suitable. If this is not the case then you must fake the qmake command to suit your environment. Alternatively, one could also modify the Makefiles:

<span style='color:#00c000'>/home/user/qtepics</span>/qeframework/qeframeworkSup/Makefile<br>
<span style='color:#00c000'>/home/user/qtepics</span>/qeframework/qepluginApp/Makefile<br>
<span style='color:#00c000'>/home/user/qtepics</span>/qegui/qeguiApp/Makefile<br>

to suit your environment.

MinGW compiler

Since commit 69d1623 (qeframework repository 8/July/2017), the _MINGW macro is automatically defined TRUE if the EPICS_HOST_ARCH is either win32-x86-mingw or windows-x64-mingw.

See the /home/user/qtepics/qeframework/qeframeworkSup/project/framework.pro project file (approximately line 92) for details.

Build Framework Libraries, Plugin Library and Display Manager

This is simply:

cd <span style='color:#00c000'>/home/user/qtepics</span>/qeframework

cd <span style='color:#00c000'>/home/user/qtepics</span>/qegui


The qe_git_test_build script may be use on Linux to clone the git repositories, build the framework libraries and build the qegui display manger.

I use this after each git push update to ensure the head version of the code can still be successfully built; I do this using both Qt4.8.4 on CentOS 6 and using Qt5.10 on CentOS 7.

Run qe_git_test_build -h for help information.

While not intended as a general purpose download and build script, it could be the basis of such a script that would suit your facility.

qtcreator Build

This getting started section assumes the reader is familiar with qtcreator.

There are three separate Qt projects, one each for qeframework, qeplugin and qegui. There is no overall project to build them all. Note: the archapplDataSup must be built command line style.

One consequence is when building the QE Framework using qtcreator, the framework project must be configured with an extra build step in install the header files so that they are available when building the qeplugin library, qegui program or any other QE Framework client. This step is done automatically when using the headless build option described in the previous section.

Another consequence is that in addition to the environment variables required for the headless build as described above, the environment variables EPICS_BASE, ACAI, QE_FRAMEWORK and if required ADSUPPORT must also be defined manually when using qtcreator.


Using /home/user/qtepics as the git clone location, open the following project file in qtcreator:


During the qmake phase the following message is output.

Project MESSAGE: Note: By default qtcreator does not have a 'make install' build step. When using qtcreator, modify project
Project MESSAGE: ....: to add an install build step which is required to install header files to ../../include

To do this, open the project build configuration page in qtcreator and click on Add Build Step button/combo box and select Make. In the Make arguments line edit specify install. In the existing regular make step, consider adding a -j N argument to allow parallel compilation (where N is the number of available CPU cores).

Note: if you know of a way of automatically adding this build step by adding some directive into the project file, please do let me know.


Still using /home/user/qtepics at the git clone location, open the following project file in qtcreator:



Again using /home/user/qtepics as the example, open the following project file in qtcreator :


Last updated: Fri Jun 25 11:55:26 AEST 2021