Infrared Configuration

Pixcel can be configured in 3 ways. By pressing buttons on the GUI, changing values in pixcel.ini and sending new values over the remote link

Pixcel.ini

Pixcel follows the windows3 convention of having a .ini file to store configuration and setup from one run to the next. This is a plain text file with one entry per line and a format of KEYWORD=VALUE Each set of parameters are grouped under a >[HEADING].

All of the parameters of the program can be set by editing the values in the .ini file, many of these values are linked directly to controls on the gui. Others can only be set by quiting the program and changing the .ini file. A subset of these parameters can also be set remotely if this wouldn't cause problems for a running system. That there are such a large number of configuration parameters is a tribute to the flexiblity of the astronomers minds and working practices.

Notes:

Values are either

Parameters

The new parameters are in five groups at end of the pixcel.ini.

Infrared

SUBTRACT=TRUE/FALSE
Displays and saves the data with the reset level subtracted. In RRR mode the reset level is subtracted separately for each image, in NDR mode the first read is subtracted from subsequent reads.

CONSTANT= 0 to 65535
Adds the value to each pixel after subtracting the reset, used to prevent negative values where noise would give a readout level below zero.

ASSEMBLE=TRUE/ FALSE
Combines the data from fourquadrants into a single fits file when saving. If only a single quadrant is selected this setting is ignored.

AVERAGE=TRUE/ FALSE
In RRR mode computes a running average picture which is saved as read 000.

LINEAR=none or filename
Corrects the data for non-linearity by substituting the value read with a value taken from a file. The file should be plain ASCII text containing one number per line. The number on row n is the value to use to replace the value n. eg. To have no effect on linearirty the file should contain the number 0 on the first line through to 16383 on the last. The file must contain exactly 16384 lines (ie 2^14).
none turns this feature off.

IDLE= TRUE/ FALSE NOT USED
Sets the camera to flush the arrays every second while not reading out.

DETECTOR=Hawaii / picnic / hawaii2
A text value identifing the detector, only used for the DETECTOR keyword in the fits file

CAMERA=Cirsi (or Cohsi etc)
A text value identifing the camera, used for the CAMERA keyword in the fits file

SAM
A text value used to give the SAM type and version, appears in the SAMVER keyword in the fits file.

READS=1 to n
Number of reads selected by the read box in the infrared sequence control. In NDR mode this number of reads is made at each loop. In RRR mode it is ignored.

PRE_READ=TRUE / FALSE
If true the camera is readout before the start of each sequence and the data discarded. This avoids any artifacts which occur in the first frame due to saturation or remnants of earlier images.

ROTATE=TRUE / FALSE
Rotate the image from each chip through the angle set below when saving the fits file.

ROTATE_ORDER=0,90,180 or 270
The angle to rotate each chip through when saving the fits file. Used to keep North and East consistent in CIRSI where the chips are physically rotated.

FLIP_V=TRUE / FALSE
Mirror the chip image around a horizontal axis before saving. ie Top row becomes the bottom row in the saved image.

FLIP_H
Mirror the chip image around a vertical axis before saving. ie First column becomes the lasr column in the saved image.

SHIFT=0 to 1024
The number of pixels to shift the start of the image to remove extra spurious pixels introduced by the controller. Typically 3 but set to 0 to turn off.

Fits

SAVE_TIME=0 to 999
An estimate of the time taken to read the arrays and save the data. This is used by the system to decide whether to save the data during the exposure time between reads or save all the data at the end. Set 0 to force interleaved saves or a long time such as 999 to force save at the end. See the timing section for more details.

SAVE_RESET=TRUE / FALSE
An In NDR mode, saves the reset image which was subtracted from all the other images.

RUN_PAD=0 to 9
The number of characters to pad the run number field in the filename to. Useful if the reduction software needs filenames with the same length.

RUN=0 to 9999999
A run number is inserted into the filename of each fits file written, the number is automatically incremented with each new sequence. To disable this feature set RUN=0

LINES=0 to 999
A number of blank lines can be inserted in the end of the fits header before the END record. This allows later data processing software to add its own keywords without having the extend the file.

LIST_CHIPS=TRUE or FALSE
Includes the number of the chip and quadrant in the file name, eg _c1q3_ for chip 1 quadrant 3.

PREFIX=none or string
A string to prepend to each filename before the run number. Set none to turn off this fearure.

OBJECT=name
The name of the object, used in the fits header and in the filename if OBJECT_FILE is set.

OBJECT_FILE=FALSE or TRUE
If true the name of the object as entered in the Object box will be prefixed on the filename when saved. If set to false the filename will start with the run number.

FPA_ID=name1,name2,name3,name4
A string stored for each chip to uniquely identify it.

TYPE=string
The type of observation as selected in the Observation box, eg DARK, FLAT, SCIENCE this will also be placed in the fits file with the OBSTYPE keyword.

FITSFILE=none or filename
This allows an external fits file header segment to be inserted into each file saved. The external file must conform to the fits standard for formatting but can have a CR at the end of each line allowing it to be written with a standard text editor.
If set to none, no file is read

FILTER

FILTER_POSITION=0 to 7
The current selected filter position, select with the filter pull-down menu.

FILTERn
The name of each of the filters in the wheel, as used by the filter pull-down menu. These should be strings containing no spaces.

Log

LOG_FILE=filename (or path or none)
Those fits header parameters which are the same for the whole sequence are written to a file which can be included in a database. There are four ways to specify the file.

LOG_FORMAT=csv or html
this entry is used for the file extension of the log file. If LOG_FORMAT is htm or html then html table format is used. If csv a comma separated variable list is used.

Remote

REMOTE=TRUE/FALSE
Enable remote control connection.

PORT=n to 32767 Note: changed from SOCKET
The port number to use for the remote connection. Standard is 23 (telnet) but any unused socket can be used.

ALLOW=ip1,ip2
A list of IP numbers of clients allowed to control the camera. Set to 'all' to allow any host.

ENABLE_WARNINGS=TRUE / FALSE
If set to false warning boxes on the screen for non-fatal errors are suppressed, this is used for remote operation where no one would see the messages.

Other parameters

There are a number of parameters in the ccd sections of the original pixcel.ini file which can be changed. Most of these are directly controlled by the gui and shouldn't need changing by the inexperienced (or astronomically trained) user. 

[CCD_PROPERTIES]
CCD_GAIN=0.340
PARALLEL_TIMING=15,0
ACTIVE_AREA=0,0,512,512
CCD_HEIGHT=512
CCD_WIDTH=512

The CCD_GAIN is the output gain of the detector in uV/e divided by 10. ie 1 = 10uV/e, for Hawaii arrays at normal speeds 0.34 is approximately correct. Changing this wil have a linear effect on the gain value dsiplayed on the camera tab and written in the fits file.

The PARALLEL_TIMING is the pattern of qquadrants to read out. This is stored in 2 bytes. The first value controls chips 2 and 1, the second chips 4 and 3. In each byte the top 4 bits is the even chip and the low 4 bits the odd chip. ie 15,0 is all quads chip 1. This is controlled by the gui and shouldn't need changing by the user.

The ACTIVE_AREA and CCD_ is the size of a quadrant. Set this to 512 for a hawaii-I, 1024 for Hawaii-II and 256 for PICNIC. 

[LINK_CONTROL]
IO_BASE_ADDRESS=336

The io address is the address of the AT link card on the ISA bus, unless you have chanaged the junmpers on the card this doesn't need changing. Valid values are 336 (0x150) and 768 (0x300). 

[DDE_CONTROL]
SAM_TYPE=4

This controls the type of timing in the SAM in the controller, values 0-3 are used by the CCD system. Values 4,5,6 are used for the infrared arrays. This value affects the displayed rate and gain.

Ask your supplier which SAM type you have. Note that the SAM keyword in the INFRARED section is only a description for the fits header. 

[PDCI]
PCIDeviceId=0x826e

The PCIVendorId may have to change depending on the type of PDCI capture card fitted. See the configuration section for more details.