Roper Photometric User Manual

Page 16

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10 Advanced Camera Operation Manual

You can use this function to stack several regions, one after the other, in the parallel direction. However, you
cannot stack more than one region at a time in the serial direction.

s_offset

may be zero. All other

parameters must be between 1 and 65,535, inclusive.

s_size

and

p_size

must be at least as large as their

corresponding

s_bin

and

p_bin

. Finally,

s_offset

and

s_size

must be no larger than the CCD serial size.

script_begin( );

This must be the first instruction in the script. It signals that the script is starting now. Any text that occurs
before this instruction is ignored. This allows you to put in an initial comment block that can be used to
explain the purpose and operation of script programs. This instruction automatically puts the CCD into

shift_mode_is

.

script_end(

contin_clear

);

This must be the last instruction in a script. It signals to the compiler that the script program is now finished.
Any text that occurs after this instruction is ignored. If the parameter

contin_clear

is 1, the camera remains

in continuous clear mode. This indefinitely cycles the CCD in a shift-and-eliminate-charge loop, similar to the

clear_until_trig

instruction. Since this actively cycles power through the CCD, it also generates heat

within the CCD. This may be a problem in some cases, particularly if the camera is run near the low-
temperature limit. Continuous clearing occurs until a new script or exposure is started, an abort is sent, or
until the camera hardware is reset or turned off. Other commands to the camera (such as altering the speed
setting) also cancel continuous clearing.

contin_clear

must be either 0 or 1.

shift(

number_of_lines

);

This function shifts the

number_of_lines

rows of data, in the parallel direction, using the current shift mode.

Depending on the shift mode in use, this may or may not shift the entire parallel register (it may shift only the
storage array), shift the rows either forward or backward (depending on the setting of the ALT shift modes),
or use MPP mode for the clocking. The serial register is cleared during the shift operation, so any charge
dumped into the serial register is eliminated. The two most common cases are described below:

shift_mode_is

or

shift_mode_ism

: In these two modes, the entire parallel register is being moved.

Issuing the instructions

shift(3);

moves the entire parallel register 3 rows closer to the serial register.

The far end of the parallel register is filled with zeros (no charge). The three rows closest to the serial
register are dumped in to the serial register and cleared.

shift_mode_s

or

shift_mode_sm

: These two modes can only be performed on frame-transfer devices.

Issuing the instruction

shift(3);

moves the storage array three rows closer to the serial register. The far

end of the storage array is filled with zero (no charge). The image array is completely unaffected (it is
often left exposing). The three rows closest to the serial register are dumped into the serial register and
cleared.

Please note that the

alternate

shift modes are usually loaded at the factory with settings that are identical to

the normal modes. You can request custom settings that allow backward shifting, shift image only, etc.

Also note that shifting is not useful for outputting pixels. It is useful only for moving a region into position for
readout. Readout must be done through the

pixel_readout

command.

number_of_lines

must be between

1 and 65,535, inclusive.

shift_image_to_storage( );

This function can only be used on frame-transfer devices. It shifts the CCD’s image array into the storage
array, and any data currently in the storage area is lost. (It is shifted into the serial register, and the serial
register is then cleared.) Although this operation could also be accomplished using appropriate combinations
of the

shift

instruction and various shifting modes, this function does the operation more efficiently with a

single instruction. Please note that using this command leaves the parallel shifting mode set to

shift_mode_s

.

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