Skip to main content

Users guide

All information for users can be found in the user guide webpages applicable for all beamlines.

Useful programs for data processing

Powder diffraction data can be integrated using FIT2D or DIOPTAS.

Integration of single-crystal data can be performed with CrysAlisPro.

Useful commands on the beamline


Open the bliss session to collect data/ make scans

To open the shutter


To close the shutter


To go to the “camera” position: to measure pressure


To go to the “beam” position: to collect X-ray data

dscan(motor, -n, n, step, sec)

  • Motor: ceny for the horizontal pos// dacz vertical one
  • -n, n: starting and final position. In mm
  • Step: number of points taken for the scan. Usually 40
  • Sec: acquisition time. Use 0.1


Go to the centre of the scan


Go to the peak of the scan

umv(motor, ± number)

  • Move the sample stage in the given (number) position
  • Motors: dacz, ceny, IVU20c, pace1_axis, pace2_axis

umvr(motor, ±number)

Move the sample stage, relatively, of number millimetres

tweak(motor, 0.1) than + or -

Move the selected motor of 0.1 mm in + or -. Pressing again + or – will move again. Press any other key to exit.


Display the position of all motors


Display the position of the selected motor

name of the motor

Gives all the info about the chosen motor


Save the position in which you are as POS1 (same for POS2, POS3)


Go in POS1.


Gives the values, in ceny and dacz, of POS1.


Displays all the parameters of the last oscillation


Collect data: from -32° to +32 °, step 0.5°, counting 0.2 second/frame

Recall the previous used data collection,1,1.5)   

take only one frame, from -1° to +1°, counting 1.5 seconds






























  Mesh 2D

  oscillation.dmesh(ceny, -0.1, +0.1, 2, dacz, -0.1, +0.1, 2)

  In this way the 9 measures will be collected accordingly to the following grid

  NB looking at the camera ceny is increasing from the right to the left; dacz from the bottom to the top;

 the point N5 will be in the centre (ceny=0, dacz=0)

  • 9
  • 8
  • 7
  • 6
  • 5
  • 4
  • 3
  • 2

 Please note that there is little sense to create a grid with step lower than the size of the beam





GAP; for SC between 12 and 12.6, for powder between 7.05 and 7.21


Move the sample stage along the horizontal direction


Move the sample stage along the vertical direction


Move the sample stage on the beam direction


Detector-sample distance, usually 180 mm for single crystal, 250 for powder


Control the omega rotation of the sample stage


Move the beam stopper


Change the power of the laser for ruby measurement


Control the pressure of the membrane (gate pace1)


Control the pressure of the membrane (gate pace2)

Increasing membrane pressure

pace1 or pace2

To see the pressure (P) of pace1 or pace2. You will see two things:

input: pace1_in@ n bar      which is the pressure in the tank (same if pace2 is typed)

output: pace1_out@ n bar  which is the pressure in the membrane

pace1.setpoint= n

To set the P of pace1 to n. While pressure increases you can type other commands

umv(pace1_axis, n)

To set the P of pace1 to n. While pressure increases you can’t type other commands

n has to be >0.1 bar

pace1.ramprate= n

It changes the ramp rate to n bar/min (if 0 is set the speed is maximum)


cd⁓/scripts/nedit     Load the single crystal script to convert a single data collection
cd⁓/scripts/nedit     Load the single crystal script to convert a series ofdata collection
cd⁓/scripts/nedit                                Load the powder script 
cd⁓/scripts/nedit do_pyFAI-average_loop        Load the powder script (preferred)

NB: It is critical, before converting a dataset, to change the parameters (e.g., dd, λ, X, Y of the center) of the loaded scripts

 phyton  ⁓/scripts/  name_000n     You have to be in the main folder of the sample experiment. 
                                                      Just launch command the program will read all the info in the first lines of the .h5 file.
phyton  ⁓/scripts/do_eiger2crysalis_loop  name nn NN         You have to be in the main folder of the sample experiment.
                                                     Just launch the command; the data of the folders between number nn and NN will be converted
python ~/scripts/ name nn NN       For powder. You have to be in the main folder of the sample experiment. 
                                                      Just launch the command, all .h5 files will be converted in .edf ( nn first dataset, NN last one)



Zaber console crashes: close the window and restart it. Choose COM1 as the device to connect. Change the units to mm for motors. Then make a small movement for each of the motors (0.01 moves) to see the absolute values of the microscope.Troubleshooting

Error value out of range when measuring ruby: the beam is too intense and saturates, so either reduce the acquisition time, move slightly off the ruby, or reduce the laser power by typing umv la 0.64 in the exp window. Check first the value of la before changing it by typing wa. Lower values reduce the intensity of the beam, while higher values increase it.

PRL system crashes: Restart the PRL program. Need to do the calibration after restart. Place the light into the PRL system and press calibrate, should have three main peaks. Take away the light source and continue as before.

Beam loss: Check the IVU20c gap after a beam loss as sometimes it can be changed to higher values. Check that the front end is open.

No diffraction: Check that the pinhole is correctly centered (especially after moving/changing the cell). Check that the front end is open (especially after a beam loss). If not, open FE and start auto.

Also find the wiki link (still not completely updated) with more details.