The robotic sample changer installed on all the MX beamlines is a result of a joint collaborative effort between the ESRF, the EMBL Grenoble outstation and BM14 (MRC France).

Some useful webpages to check

There is a sample changer BLOG web page available to check any work carried out on the sample changer. Please check this BLOG if you are having a Sample changer problem in case some intervention occured recently. Login with the usual op(i)dxx login/password.

In addition there is a 'Sample Changer Category' in MxFeature to keep track of feature requests and bugs.

There is also a sample changer statistics page maintained by Ludovic Launer, and can be accessed by clicking here.

Simple Manual

The following is not yet a full User Manual but a simple guide for Local Contacts.

The computer names are those for ID14-2 : the page will be updated with the other computer names on the other beam-lines once the SCs are installed.


The Sample Changer (SC) control consists of hardware - the PMAC controller (Fig. 1) - and software which runs on the SC Windows PC which is in the computer rack in the experimental hutch (Fig. 2).

The SC PC on ID14-2 is called pcsc3-eh2.

The computer screen in the experimental hutch links via a KVM box (next to the screen) to 2 computers :

marmite : KVM port 1, for minidiff buttonbox control, runs Exes_ProDC, Linux PC
pcsc3-eh2 : KVM port 2, for running the SC device server, Windows PC

The login/password for both is opid14/tonic14.


Starting the Sample Changer (if everything is off!)

1) Make sure the PMAC controller is switched on. If not, turn it on using the switch at the back of the PMAC rack (Fig. 3) and then press on the green button at the front (Fig. 4). If you need to turn the PMAC off, press the red button at the front first and then switch off at the back.

2) Make sure the SC PC is running. If not, start it up (as for a normal Windows PC) and log in (opid14/tonic14).

3) If you had to start up the SC PC, double click on the "Start Tango Events" icon in the middle of the screen. A black window will appear for around 3 seconds and then disappear (this is normal!). This starts a process called notifd.exe and you can check if it is running by looking at the processes in the Task Manager. For ID14-EH3: Tango server automatically starts when double clicking on the Sample Changer icon.




4) Start the SC device server and GUI by double-clicking on the "Sample Changer" icon in the middle of the screen. The GUI is the same as the one we use on ID14-3. We do NOT use this GUI with the mini-diff so we need to lock it.

5) Lock the GUI on the Windows PC by clicking on "Devices" from the menu and then "Lock Local GUI". At this point you are asked for a password - there is no password just click on OK.

6) Start mxCuBE: for the moment we need to run it from marmite but on bob2, so telnet bob2 (opid14/tonic14) and set the display to marmite:0 . Then type 'mxCuBE'. For mxCuBE to run properly, Spec needs to already be running otherwise all the motor windows will be red!


NOTE : The above is a full list - most of the time the PMAC controller will already be on and the PC will be switched on with all the necessary software running.


Using the Sample Changer

You should load and unload samples using the Sample Changer tab in mxCuBE.

The application is colour coded as follows :
green : All is OK
yellow : Something is moving
purple : Warning, but doesn't stop SC from working
red : Fatal Error, stops SC from working, must go into exp. hutch and Abort the current action using the touch screen

1) To load baskets :

Trouble Shooting

Basket Jam
(not very common! But quite obvious as SC makes nasty grating noise when you try to change baskets!)

If there is a basket jam the mxCuBE software will tell you there is a fatal error and turn red. It will also tell you that the error is a basket jam.

1) Go down to the experimental hutch and look at the touch screen. It will show the "Setup General" screen.

2) Take the top white cover off by unscrewing the allen screw in the middle of this cover and just gently lift it off.

3) Remove also the blue cover from the basket loading chimney.

4) Place a screwdriver through the holes in the chimney as shown in the figure below so that you can insert it into the screw end of the basket selector motor.

5) Turn the screwdriver - try both directions and turn it in whichever direction is easiest to move! - a couple of turns. The baskets should move round as you turn.

6) After a couple of turns on the touch screen press the Exit button. This should bring you back to the Sample Transfer screen. Try selecting a different basket. Now everything should move normally.


Vial Jam
(more common)

When a vial is jammed, the system stops you from trying to move the baskets, so you can no longer get a basket jam occurring due to a vial jam. A vial jam means that either an empty vial or a vial containing a pin is stuck in the chimney of the SC, and normally occurs just after a loading or unloading event. When one of these occurs you have to manually push the vial back down into the SC baskets by following the procedure :

1) Go down to the experimental hutch and and look at the touch screen. It will show the "Setup General" screen.

3) On the left-hand side of the Setup screen there is a button called "Cap Closed". Press on this and use the menu which appears to open the cap - when you press on this the brass cap covering the hole where the samples are pushed in and out of the SC will slide open.

4) Looking down this hole, you should see either the base of a pin with its 2D matrix, or an empty vial (empty vials are more difficult to see!). Take a screwdriver or a pencil and insert it in the hole until you meet a resistance and just wiggle until you feel the vial drop.

5) Close the brass cap by pressing again on the "Cap Closed" button on the touch screen and using the menu which appears to close the cap.

6) Press on Exit on the touch screen and all should now be ready to use again (the software should automatically change back from red to green once the vial is unstuck, you should not have to Reset in the software).

Communication Problems : Ultimate Recovery Procedure

Sample Changer Off - use Minidiff on it's own

If the sample changer is turned off for whatever reason and you have the message SAMPLE CHANGER LOCKED / MINIDIFF LOCKED in spec you cannot move any minidiff motors. To get the minidiff working type in spec:

  • SCInUse 0

    Spec should now display SAMPLE CHANGER NOT IN USE / MINIDIFF CAN MOVE and everything should work.

    For ID14-EH3: in microdiff software go to Option-Hardware Setup; in 'Sample Transfer' choice 'Manual Mounting' instead of 'Use Sample Changer'