Cryo-EM instrument workstations can be monitored and remotely controlled by authorized users via the FastX remote desktop application (web or desktop client).

Prerequisites

In order to gain access to the remote session you must first:

  1. Have a valid SLAC Windows Active Directory and SLAC unix account (contact Lisa Dunn for help with provisioning these accounts from SLAC IT Account Services).
  2. Have access to a web browser or have sufficient privileges on your local machine to install the FastX desktop client.
  3. Be able to communicate to SLAC via http from your laptop/workstation, etc. (your local network policies may differ, please consult with your local organization's IT department for more details).
  4. Be a collaborator on an active experiment.
  5. [Optional] A 4K resolution monitor is recommended for the best experience.

FastX Web Client

  1. Open the following link in a web browser: https://fastx.slac.stanford.edu:3300
  2. Log in with your SLAC Windows Active Directory credentials.

  3. Under Applications, double-click on the one of the virtual desktop icons to launch the desktop session:
           a. KDE:
         
              i) Click the Application Launcher icon on the lower left, then click on Favorites→Konsole to launch a terminal:
             
              ii) In the terminal window, run the following command to launch a remote session to the Cryo-EM instrument workstations. Replace <instrument> with the scope you are trying to connect to (e.g., tembeta ), and optionally use the -w argument to control the remote desktop(s). You will be asked to authenticate to the centos7  cluster, use your SLAC unix credentials:

    ssh centos7 '/afs/slac/g/cryoem/tem_access/bin/get_screen.sh <instrument> [-w]'

          b. XFCE
        
            i) Click the Terminal Emulator icon in the bottom toolbar to launch a terminal window:
           

           ii) In the terminal window, run the following command to launch a remote session to the Cryo-EM instrument workstations. Replace <instrument> with the scope you are trying to connect to (e.g., tembeta ), and optionally use the -w argument to control the remote desktop(s). You will be asked to authenticate to the centos7  cluster, use your SLAC unix credentials:

    ssh centos7 '/afs/slac/g/cryoem/tem_access/bin/get_screen.sh <instrument> [-w]'
  4. Once up, you should see two windows - one for the Camera and one for the Microscope. You should be able to move and adjust the windows as you would normally.

If the mirrored screen is too large for the window on your local machine, you can zoom out:

  1. Move your mouse to the middle top of the browser window (just underneath the URL bar). There should be a grey rectangular box that expands as you mouse over it
  2. Click on the cog icon
  3. Uncheck 'Use Smart Scaling'
  4. Click on the blue bar to set 'Scaling' to 0.5x
  5. You may also want to use 'adjust network settings' to optimize responsiveness or image quality. Your feedback on this matter is welcome.

FastX Desktop Client

The desktop client now requires login through the browser.

  1. Open the following link in a web browser: https://fastx.slac.stanford.edu:3300
  2. Log in with your SLAC Windows Active Directory credentials.

  3. Next to Applications, click on the "+" Icon to create a new shortcut.

  4. Input the following:

    1. Command

      ssh centos7 '/afs/slac/g/cryoem/tem_access/bin/get_screen.sh <instrument> [-w]'
    2. Window Mode:
      1. Multiple
    3. Profile:
      1. Default
    4. Run As User
      1. (blank)
    5. Name
      1. <Instrument Name>
  5. Use the Arrow next to the "Launch" button and choose "Create Application" in order to save this command for future use.
  6. Launch the session by pressing the "Play" button under "Disconnected Sessions"
    1.  
    2. You may need to click this multiple times before the session will launch, give it some time between each click.
  7. Input your Unix Password:
  8. Download and install the desktop client using the link provided:
  9. After installing the client, choose "Remember my selection", the click "Desktop Client" to launch the client.
  10. Future sessions will allow you to launch from the "Application" shortcut you created, and will directly launch the Desktop Client.

Troubleshooting:

  • We have seen on occasions where only one of the remote screens appears with the other showing a 'Connection Reset' error. In this case, please dismiss the error message dialog, close the active (working window), and try relaunching a remote session again as defined above.
  • If you get a permissions error when you start the remote session, it may be because you are not listed as a collaborator in the active experimental session on the microscope. Please check with your local SLAC Cryo-EM Operations representative for assistance.

  • If you continue to experience problems with permissions errors or you are unable to click/control the remote desktop(s), your Kerberos authentication token on the SLAC unix host may have expired. To renew your token:
    1. Close the current remote desktop windows.
    2. Return to the terminal window in your virtual desktop.
    3. Run the following and enter your SLAC unix credentials to renew your token:

    kinit && aklog

    4. Relaunch the remote desktop connection:

    ssh centos7 '/afs/slac/g/cryoem/tem_access/bin/get_screen.sh <instrument> [-w]'
  • If you are still experiencing difficulties with connecting via FastX report these issues with your SLAC username(s) and steps to reproduce to your SLAC Cryo-EM Operations representative, or submit a ticket via email to Unix Admin: unix-admin@slac.stanford.edu.


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