xpdAcq Configuration

xpdAcq uses glbl and xpd_configuration to controls the overall behavior of the beamtime. All of the values of the glbl and xpd_configuration have reasonable default values, but these can be interrogated and overwritten.

Funtionality related options

Functionality related options are managed by glbl and you can interrogate the default values by typing:

glbl

You can also change them if needed. Here are few possible scenarios:

No automated dark collection logic at all:

glbl['auto_dark'] = False
glbl['shutter_control'] = False

Want a fresh dark frame every time ``xrun`` is triggered:

glbl['dk_window'] = 0.1 # dark window is 0.1 min = 6 secs

Want a 0.2s exposure time per frame instead of 0.1s:

glbl['frame_acq_time'] = 0.2

changes made to glbl will be recovered after coming back to ipython session. So you don’t have to redo the changes from time to time.

The glbl also has a swap method. This method allows you to temporarally change the value of a key in the glbl. For instance

with glbl.swap(dk_window=1000):
    xrun(1, 1)

This will run the scan with a dark window of 1000 seconds. However all subsequent scans would have their dark window set to the old dark window. This is very useful for overnight scans where the state of the glbl might not be remembered.

Device-related options

Device related configurations are stored in xpd_configuration and you can interrogate the default values by typing:

xpd_configuration

You may also change the defaults:

Want to run temperature ramp with different device:

xpd_configuration['temp_controller'] = eurotherm

Want to use alternative shutter:

xpd_configuration['shutter'] = shctl2

All of the changes applied to xpd_configuration only lives within one ipython session. So if you exit out the terminal and come back, remember to repeat the configuration step again.

Note

desired objects (eurotherm and shctl2 above, for example) should be properly configured. How to properly configure a device is beyond the scope of this website, if you have specific requests, please contact beamline staff for more details.