In order for information to be saved, restored, scaled or otherwise manipulated, an empty directory must first be created in which to work. The Linux command "mkdir <directory name>" is used for this. It is suggested that the directory name be used to identify the particle run. Linux directory names may be up to 255 characters long. For example, "Au+++3.0MeV" could be the name for a triple plus gold run at 3.0MeV particle energy.
Next change into the directory just created by typing: cd <directory name>
Many of the commands described in the previous section use the current directory as a place to read from and write information into. Most of them are also implemented using Linux shell scripts (please see the Linux manual pages for bash). They in turn use the programs "ReqPar" and "dbmod" in order to communicate with the control system.
The program "ReqPar" reads from a list of tag names and asks the control system for the current values. The values obtained are written into a disk file along with the tag name.
The program "dbmod" may be used to send values to the control system from files created by ReqPar. The files containing the lists of parameters to obtain from the control system and the lists of parameter values obtained are text files and may be created or edited by a standard text editor such as vi.
This is a save of all of the tables in the database. Each table is stored in a seperate disk file. The disk files have as their names "<table name>.sav" The commands "up" and "updaemon" are used to save the tables. The command "down" is used in place of "dbload" at startup time in order to reload the saved database. The format of the command is: down all sav
Saving the complete database is most useful in cases where it is desirable to restore the system to a running state without going through a cold start process. For example, if the computer crashes in the middle of a run.
The program "up" is a voluntary save. The operator enters the program and a menu appears asking which tables to save. The usual method is to save of all the tables. The program may then be exited or left running to resave tables when the operator desires. Usually only the DATA table will need to be resaved.
The second program "updaemon" is a one minute interval DATA table save. When the program is invoked, all of the tables are saved. After that, the DATA table is resaved at one minute intervals until exited. The program is exited by pressing "ctrl-C".
A listing of the saved database may be obtained by using "listit".
A particle run is saved by retrieving the values of individual parameters from the runtime database. The saved parameter values are stored in disk files and may be sent to the control system later in order to recreate a run of the same type. They may also be processed by the scaling program to create a run for another energy or ion species.
The program "request <arg>" is used to obtain lists of values from the running database.
The program "send <arg>" is used to send previously obtained lists of values to the running database. The machine parameters are organized by sections of the machine. For example, typing "request S2sav" obtains a list of all values from source 2 to the entrance of the machine.
One peculiarity to note in regard to the bending magnets is that when using S1sav, S2sav, etc as arguments to "request," the field strength setting parameters for the bending magnets must be set to agree with the field strength reading from the hall probe. The field strength setting is sent to the control system when the file is sent, thus invoking the magnet tune routine.
When the machine scaling parameter lists are requested (S1, S2, 1B, etc), the hall probe reading is retrieved and the field setting is generated, therefore this is not a problem.
The program "extract <arg>" may be used to obtain a parameter list from a database previously saved by "up" or "updaemon".
The recommended procedure for saving a particle run using S2 is:
Make a directory to hold the run.
Change to the directory just created.
Check to make sure the magnet field settings match the hall probe readings.
Check to make sure selected ion source, selected beam line, particle name, input mass, output mass and charge state have all been set.
Check to make sure the double slit position settings match the position readbacks and set if necessary.
If running in slit mode check to make sure TRV is set to match GVM.
Type "request S2sav"
Type "request MACHsav"
Type "request 1Bsav"
Type "request DS"
It might be helpful to use "vi" to make a file containing notes about the run. For example, the stripper gas and source heater settings.
It also might be helpful to use "up" or "updaemon" to save all the tables. This can be helpful later if the run needs to be scaled, someone wants to look at an odd parameter value, or get a listing.