As with the previous IR array control software, ``parameter sets'' are used to control the attributes of data acquisition. A listing of the parameters is given below. Because the data are saved directly as IRAF images, note that parameters include not only observation-specific items such as integration time, but archiving items such as the IRAF filename and the header and pixel directories.
In general, the parameters fall into three categories:
above).
The command ped will open an editing session on the current parameter set, listing each parameter in turn and prompting for new entry (<cr> returns the present value). At the beginning of a run, one should execute ped and set up those parameters falling into categories 2 and 3 above. NOTE: One cannot specify a non-existent header or pixel directory in ped; it is necessary to go to the IRAF XTERM window and create those directories first! Since it is cumbersome to go through the entire parameter list for each observation, there is a command eask, which runs through the entire parameter list, permitting the observer to specify which parameters will be listed (specified by l) or queried (specified by a) at the beginning of each observation. Entering la for a parameter selects it for the ``observation menu''; entering l excludes it for the observations but leaves it in the parameter-editor. NOTE: The ``up arrow'' key may be used to back up through the ped list if one wishes to change a previously entered parameter.
When this is complete, save the parameter set with the command psave <filename>. This will save both the edited parameter set and the menu selected by eask in the file `<filename>.par'. Should the system crash, this information may be retrieved by the command puse <filename>. Should major changes be made to the parameter file, such as change of header or pixel directory (say on another night of the run), it is a good idea to psave the updated file so it, and not the previous version, will be recovered by puse.