Advanced Photon Source

An Office of Science National User Facility

Beamline Controls and Data Handling

Control Software

The 7ID beamline operates thru EPICS.  The standard MEDM graphical interface is in use but is due to be updated soon.

Diffractometers are generally controlled with spec.

  • A brief list of of handy spec commands is available, with an even briefer two-page summary.
  • A brief guide to local macros in use at 7ID is available here (local access).
  • The vendor has some guides available here.
Data Formats

The format in which data are saved depends heavily on the method of data collection.  For example:

  • spec data are usually saved in ascii files.  These files can grow long and unwieldy unless new files are created from time to time. 
    PyMca is a useful viewing and analysis software for spec files and for x-ray fluorescence data.
  • Data collected with EPICS scan records are saved as binary mda files, with separate files for each scan.  Utilities to manipulate these files are available here. dview (available from the main MEDM screen under the "Tools" menu) is a handy way to view 1D and 2D data.
  • Area detector data are saved as tiff files or per the manufacturer's standard.
Data Transfer

To facilitate users returning their data to their home institution, the APS hosts an anonymous FTP server.  Beamline staff will assist users in loading data onto the FTP server.  To retrieve the data from the FTP server using a web browser:

  1. Navigate to .
  2. Navigate to the appropriate subdirectory. 
  3. Click on the files you wish to download.
If you wish to use a terminal-based ftp client:
  1. Type ftp
  2. Use the user name anonymous
  3. Just hit Enter when asked for a password
  4. Type cd  /pub/sector7/
  5. Type ls to see a listing of files on the server. Perform get operations to retrieve your files.
Data Retention Policy

While the beamline will store users' data temporarily, the ultimate responsibility for data retention lies with users.  Data from the 7-ID beamline consists of EPICS and spec scan data files, and area detector images. The EPICS and spec scan data are stored on a central institutional server for a minumum of 3 months. Both area detector data and scan data are provided to the users after the experiment completion. A copy of their image data may be kept at the APS, but this is left at the discretion of their local contact.