The ESRF MX beamlines are all equipped with minidiffractometers controlled via the MXCuBE data collection software, apart from ID14-3 which is equipped with a microdiffractometer and associated Windows-based software as well as the MXCuBE software.

The goniostats are all single phi rotation axis unless the motorised mini-kappa system has been added. The rotation axis is computer controlled and the user is provided with an easy to use GUI to perform all the tasks associated with mounting and centering a sample.

For minidiffs, the MXCuBE GUI "Hutch" tab has a sample viewing and centering area on the right-hand-side where the user can control the zoom, lighting and focus of the sample viewing camera, and can centre the crystal using one of the following options :

• 3-click centering : The user clicks 3 times on the part of the crystal which is to be centered and the phi axis rotates by 90degrees between each click. After the 3rd click the sample is centered on the beam.
• Assisted centering : Working with DCP (Data Collection Pipeline)
  
• Automatic centering : The sample is automatically centered in the beam using image recognition routines firstly of the loop and then of the crystal. This procedure takes longer than the 3-click centering and should only be used in full pipeline mode when the beamline is being run unattended. This procedure has a 70-80% success rate - reasons for failure can be very icy samples, multiple crystals, strange shadows due to lighting etc.

For microdiffs (Id14-3 case), the Windows-based GUI has three main buttons SAMPLE TRANSFER, SAMPLE CENTERING and BEAM LOCATION. To mount a sample first, click on TRANSFER SAMPLE button. In this phase you can set up the default sample loop length for your experiment. To center a sample, click on the SAMPLE CENTERING button and proceed by using the semi-automatic 3-click centering procedure after zooming down to the lowest setting (with slider) or the automatic centering procedure described above. To move the crystal horizontally (phi translation) use the the "Y Translation " bar.