Photometrics PXL Camera System Procedure

C. Harper 7/9/01

 

 

A.     Hardware

 

1.      Connect cables from the camera head to the Camera Electronics Unit, and from the host computer to the Camera Electronics Unit via the A2S Converter box. See PXL User Manual for instructions.

 

2.      We are using a larger Melles Griot shutter instead of the shutter supplied by Photometrics. The Melles Griot shutter is rated at 6v and is wired to plug into the shutter control connector on the front of the camera.

 

3.      Modifying the Melles Griot shutter to replace the Photometrics shutter: The black and green connector wires are soldered to the two coil wires on the shutter. The black and yellow connector wires must also be soldered together before going into the coil. The Melles Griot shutter doesn’t have an over temperature device attached to the coil like the Photometrics shutter. Connecting the yellow and black wires together in place of the over temperature device creates a complete circuit.

 

4.      Connect the cooling unit to the camera.

 

B.     Software

 

1.      We are using a modified version of “camtest” called “kcamtest”. It currently resides at: /u/harper/pxl/PXL_keck/pxlsetup.lick  and can be opened by:

harper@shoppe: /u/harper % camera.

It will eventually be installed on loel host. “kcamtest” was modified for Keck and it will allow you to save images.

 

2.        Refer to the Photometrics Software Guide for Sun Workstations for installation questions.

 

C.     Imaging

 

1.      All hardware and the cooler must all be powered on before loading the PXL camera program (see PXL Power Sequencing Procedure). First power on the cooler and give it time to circulate cool coolant. Next turn on the Camera Electronics Unit. The A2S and the host computer remain on at all times. Check to make sure that the green light is on for both the A2S and CEU box. If the yellow light stays on the A2S box and/or the red light comes on the CEU you will need to troubleshoot these problems before continuing on.

 

2.      The CCD must be cooled down to the setpoint temperature. It takes about 25 minutes to cool down to the –25 C setpoint.

 

3.      To load the “kcamtest” program:

harper@shoppe: /u/harper % camera

In the menu bar of “kcamtest” you may need to choose camera, then open and pvcam2.

 

The current CCD temperature can be checked by clicking the camera button in the

menu bar, then status. A CCD temperature window will appear that displays the

updated CCD temperature. Wait until the CCD is cooled all the way down before taking images.

 

4.      The Camtest window will come up with 5 menu options: File, Edit, View, Camera and Exposure.

 

5.      Check the exposure time by clicking on the Exposure menu, then Setup. The default value is 100 ms.

 

6.      Take an exposure by clicking on Exposure, then Single. The image will appear in the Camtest window and a readout time will appear at the bottom of the window.

 

7.      Save an image by clicking on File, then Save As and enter the file name with .fits, then OK.

i.e. /u/harper/file name.fits

 

8.       Open a file by clicking on File, then Open and go to the top level directory in the Filter box: /u/harper/*.fits

Hit return while the cursor is in the Filter Box and at the end of the path. Then highlight the desired file and hit OK. The image will now be displayed. Or enter the path in the Selection box then hit OK. The pixel count is displayed in the bottom left corner. Moving the cursor will change the pixel count.

 

9.      Close “kcamtest” before powering down the CEU and the camera. Use File, then quit to exit the program.

 

D.    Changing Default Values

 

Other areas that you may want to check or change:

 

View                - Setup for grey scale values and to restrict the range. This will display the minimum and maximum values.

 

Camera           -  Open is used only when using multiple cameras

                        -  Specification will display the camera specifications

-  Setup will show the temperature setpoint and the delay time that it takes to open the shutter after the signal is given. This may need to be adjusted for each shutter.

-  Status displays the CCD temperature

-  CCS State for halt, etc. with the shutter

 

Exposure            -  Single for one exposure

-  Continuous for multiple exposures. This can be used to debug shutter problems

-  Setup defines readout window and how many pixels you want to read.

-Set Bin to 4x4 to set focus. The focus can be adjusted while taking exposures. Bin is normally set to 1x1 for full resolution.

 

Troubleshooting Tips

-          The original “kcamtest” program is limited to 15 bits. You must keep the images below half scale (32K) or they will wash out. There is a revised “kcamtest” program that can handle 16 bits. Bob Kibrick will be installing it on Shoppe.

-          Use “kill –9 (process number)” to stop a program. % ps will display the process number. Use this if the program locks up and restart the program.

-          If the CCD doesn’t cool down to –25 C check the cooler hoses to make sure that they aren’t crimped and impeding the coolant flow. The tubes shouldn’t be hanging over the table edge without strain relief.

-          Sequencing is important. First turn on the cooler and give it time to start circulating cool coolant. Next turn on the Camera Electronics Unit. The A2S converter and the host computer are always on. “kcamtest” won’t load if there is a yellow light on the A2S box or a red light on the CEU.

-          If a yellow light comes on the A2S Converter box check the coolant tubes, connectors and reboot Shoppe. This light should go out after a short power up self diagnostic is run. If it stays on it indicates an internal problem in the A2S unit.

-          “PVCAM Fatal Error in init_data_structures: this driver is already in use by another user” error message may occur while trying to load “kcamtest”. The driver wasn’t released when the program was last closed. Try rebooting Shoppe or “super reload-driver”.

-          Shoppe is very slow, give it lots of time.

-          Cam_open_cb: Can NOT open new camera, pd_cam_open:errno = 6 indicates a SCSI problem, not a camera problem. Check:

-run “probe-scsi-all” to see if the host computer is recognizing the SCSI bus that the camera is on.

-use a slow narrow SCSI board. Fast wide SCSI board may be too fast for the slower PXL A2S’s SCSI board.

-use an isolated SCSI bus.

-try “boot –r” to reconfigure the host computer’s device maps.

-Check camtest software and PXL driver configuration by using the following procedure for getting a PXL camera to operate on a SCSI bus other than SCSI bus number 0, then reboot host computer again.

            The specific procedure, as derived from Myrna's 1999 Jon Chalk e-mail is:

 

        A. The pxl.conf file in /usr/kernel/drv on shoppe was edited to:

 

                name="pxl" class="scsi"

                        target=5 lun=1;

 

            Previously, the value of the "lun" parameter had been a 0.

 

        B. Shoppe was rebooted with a 'reboot -r' while the PXL camera was

           on an connected with the older, slower SCSI board in SCSI bus

           number 1.

 

        C. The following logical link was manually created in the /dev

           directory:

 

     pvcam2 -> /devices/iommu@0,10000000/sbus@0,10001000/esp@2,200000/pxl@5,1:4

 

-refer to Keck’s PXL Troubleshooting Procedure at:

http://www.keck.hawaii.edu:8080/electronics/operations/PXL/Troubleshooting.html