Getting or changing wavelength at F2 from ADX

• What you need for ADX to deal with wavelength changes
  
  ADX can handle wavelength 3 ways:

  1. No interaction with station computer. This is the mode at A1 and F1. The item "usewavelength" in the CCD config file (~/adsc/ccd_config) is set to 0. In Manual Control, the Define function is active for wavelength, and you can set it to whatever you want.

  2. Communication established with station computer but wavelength is not changed from ADX: "usewavelength" is set to 1, ccd_bl_station is running on the station computer and communicating with ccd_bl_cm, and MAD mode (in the Run(s) window) is OFF. In Manual Control, the Get Current wavelength function is active, and you can get the wavelength from the station computer.

  3. Wavelength is controlled from ADX: "usewavelength" is set to 1, ccd_bl_station is running on the station computer and communicating with ccd_bl_cm, and MAD mode (in the Run(s) window) is ON. In Manual Control, the Drive wavelength and Get Current wavelength functions are active.

• How commands are transmitted
  
  When a wavelength change or fetch is requested by a click in Manual Control, the ADX interface sends a wavelength_move command to ccd_dc_api, which passes it to ccd_bl_cm, which passes it to ccd_bl_station, which passes it to spec via rspec, which causes the monchromator motors to move. During a MAD data collection, commands are generated in ccd_dc_api and passed down the same chain.
  
• Startup procedure and checks
  
  On the data collection computer, use "start_ccd_plus" to start up ADX programs on the data collection computer, rspec (and friends CCDspec, OpsTerm, ccd_bl_station, spec) and the centering program (server center_server on the video-control computer in the hutch and center_client on the data collection computer).

  On the station computer, check that ccd_bl_station connects successfully to spec and ccd_bl_cm. The dialog should look like:

  Commands from ccd_bl (beamline process)
  wrote to jml_bl_sockd: CompCmd cmd="print date()" reply="OK"  alert="specerr"
  
  Response (command wait): OK
  Response (stat lambda): LAMBDA 0.979339\n
  ccd_bl_station: got wavelength, value 0.979339
  Connecting to server on host guideline, port 8032
  Got new; entering parser with cmd
  config     0.0
  end_of_bl
  
  ccd_bl_station:  entered with cmd: config (2)
  wrote to jml_bl_sockd: CompCmd cmd="getE" reply="OK"  alert="specerr"
  
  Response (command wait): OK
  Response (stat lambda): LAMBDA 0.979339\n
  ccd_bl_station: got wavelength, value 0.979339
  ccd_bl_station: REPLIED.
  

  On the data collection computer, check that ccd_bl_cm has established connections to Compumotor and ccd_bl_station:

  1. In the ccd_bl_cm window, there should be lines such as:

     Connected to f2cm1.chess.cornell.edu 5002 for cm_1, fd 8
     Connected to f2cm2.chess.cornell.edu 5002 for cm_2, fd 9
     ccd_bl_cm: connection accepted from: 128.84.182.91 with fd: 10
     ccd_bl_cm: connection accepted from: 128.84.182.91 with fd: 11
     ccd_bl_cm: connection validated for bl_cmd on fd 10
     ccd_bl_cm: connection validated for bl_status on fd 11
     Command 2
     Value 0.000000
     Command 0
     ccd_bl_cm: command: config
     output_bl2cmd: SENT at Wed May 18 13:20:08 2005: config
     output_bl2cmd: DONE (normal) at Wed May 18 13:20:08 2005: config
     Return from config, wavelength 0.979500
     ccd_bl_cm: (informational) (omega,phi,kappa): (  -999.000,    45.000,  -999.000)
     ccd_bl_cm: REPLIED.
     

  2. In the Manual Control window, Get Current wavelength function is active. Drive wavelength will also be active if MAD mode (in the Run(s) window) is ON.

  In the centering GUI, check that an image with crosshairs appears and no buttons are grayed out. If there is a centering window but it has no image or the buttons don't work, restart centering using "stop_centering" and "start_centering". This may be repeated if necessary. If there is no centering window at all, check whether the server in the hutch is working - it should have an active display of the video image and controls. If not, the hutch computer may need to be rebooted. If necessary, you can start the centering server and client separately, using "/home/specuser/CrystalCentering/center_server" on the computer in the hutch and "/home/specuser/CrystalCentering/center_client" on the data collection computer.

  If the ADX software crashed rather than being shutdown properly, use the Home button on the centering GUI to resynchronize the centering display with the spindle.

• Symptoms of a connection problem
  
  ccd_bl_station never gets past "Connecting to server" line and Get Current wavelength is inactive.

• What to do in case of a connection problem
  
  
  1. Stop the centering program using "stop_centering". Look in ccd_bl_station window for connection activity. If connection is made, you can use "start_centering" to restart the centering GUI; things should now work properly. If not, go on to:

  2. Use "stop_ccd_plus" on the data collection computer to stop everything.

  3. On the station computer, use "netstat --tcp" to look at network connections. You are looking for connections to port 8032 on guideline. If there are none, go ahead and try "start_ccd_plus" on the data collection computer again - things should work. If there are connections to port 8032 with status FIN_WAIT2 or TIME_WAIT, wait for them to disappear - may take several minutes - then try a new start. If there are connections with status ESTABLISHED, try logging out and back in. As a last resort, reboot the station computer to get rid of all socket connections.

  4. If checks (given above) are OK on the new start, you are all set. If there is a problem with the Compumotor connection, you may need to cycle power on the Compumotor.

  5. If something still doesn't work, call the CHESS operator for help.