Setting stepper motors: Saving/Restoring configurations

FIG. 1: Motor configuration form

BioCAT provides four step-packs capable of controlling up to 32 (4*8) stepper motors. None of them are used to drive the beamline optics, i.e. they are provided for users needs like moving their positioners, slits, goniometers, etc. There is also a fifth controller for eight additional stepper motors in the case one more step-pack is needed by users.

Since generally none of those motors are dedicated, users have to configure the parameters of motor resolution, speed, acceleration, backlash, and soft limits for their own needs. Those are changed per motor on the forms called from the main stepper motor menu and shown on Fig.1.

Note: In addition to changing the parameters on the computer screen users may also need to change the voltage applied to the motor on the respective step pack controller. The latter changes must be noted in the beamline LOG and reverted back to their original values after the experiment if over.

After the parameters are set it is advised to make a printout of the form on Fig.1. To make the printout, click right mouse button somewhere at the center of the form; this popups a menu with the PRINT option among other actions.

After the parameters are set for ALL of the motors, it is highly recommended that users make a snapshot of all the stepper motor parameters (and optionally of their positions) in a SNAP-file on the workstation. The SNAP-file may be used to quickly restore the whole configuration when user comes for his next experiment. It can also be helpful in the case of power outrage or any other necessity to reboot the VME crates. Certainly the voltage setting on the step pack controllers cannot be saved in the file and they need to be changed manually.

FIG. 2: Main stepper motors menu

In order to save a snapshot of stepper motors parameters, open the main stepper motor menu (FIG. 2) and click on the "Bkp/Restre" button. This will call the Backup/Restore (BURT) program:

FIG. 3: Graphical interface to Backup/Restore program (BURT)

If due to some reason the BURT program screen does not show up, then open a terminal screen and type "burtgui".

Next, click on the "Backup" button of BURT program. This should call the following menu:

FIG. 4: BURT Backup menu

Proceed to the "Request Files ..." and select there the file named "stepmotor_settings.req". Finally, select the snapshot file name of your choice (the file name must have the .snap extension) and click on the "Backup" button (FIG.4). Click on "Done" to close the forms. The snapshot files are stored in the /home/biocat/top/stdApp/op/burt directory.

To restore saved configuration from a snapshot, open the BURT program graphical interface (FIG.3) and proceed to the "Restore" menu:

FIG. 5: BURT Restore menu

Click on "Snapshot Files ..." and select your SNAP-file; then click on "Restore" and "Done".