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Setting up the IPCS

A large part of the set-up sequence for the IPCS is done by talking directly to its image-processing electronics; these operations are described in the IPCS user's manual. This section describes how to set the image format for the IPCS using the DAS.

To use the IPCS you must choose which of its CCD-camera pixels are used by the image-processing electronics. A window is defined on the detector surface outside which photon events cannot be registered. In order that photons are correctly detected up to the edge of the window, the window cannot include the entire detector: the maximum size is pixels. The margins must be at least two pixels at high and low , two pixels at high and three pixels at low . When first exposing the IPCS to a new source, the window should cover all the detector up to the margins, in order that bright spots are seen before the intensifier tube is damaged.

The photon-detection logic of the IPCS can locate photons to an accuracy of less than one camera pixel: resolutions of 1, 2, 4 or 8 are possible on each axis. The data stored in the DMS and shown on the real-time display are the sub-divided pixels.

After resolution on the fine pixel-grid, the phton events pass into the DMS' memory through a `DICI window'. This window normally passes all the photon events, but you can decrease the window size and eliminate some pixels. This allows you to see all the photon events on the real-time display, but to save to disk only the part of the image that you need.

The setup_ipcs command sets the camera size, resolution and data-transfer window; it is very similar to setup_ccd. Reformat resets the last format that you set up. Formats can be stored and recovered with these commands as noted above for CCD formats.

To set the resolution factors, use the command resolution. This command sets the DICI window to capture all the photon events.

To reduce the DICI window without changing the camera window or resolution, use the window command. This command has the same format as the command to set readout windows on CCDs. However, disable_win and enable_win are not available for the IPCS.

To view the whole IPCS for target acquisition, use overscan instead of repeating setup. After overscan, reformat takes you back to your previous camera format and saves re-typing the parameters to setup_ipcs.