History for string variable changes

In CyFlex versions 6.0.5 and newer, the “history flag” (ON/OFF) that appears in many specification files is no longer used. Instead, the “delta_hst” application assumes that almost all variables are active (history flag = ON ). This is the case for REAL, INTEGER, and LOGICAL variables, but not for STRING variables.

STRING variables are saved in an entirely different manner than the others. The history of string variables is saved in the /data/compressed/extracted/ directory. The file names are in the form of YYMMDD.<label> and are readable text. For the history of changes to string variables to be saved, the history flag must be set to ON in the spec file where the variable is created. This might be in a “gen_labels” file or in /cyflex/display_strings. We ask you to not modify the display_strings file, so if you wish to set one of the included parameters ON, copy that line from /cyflex/display_strings to the /cell/site_special file and change that flag to ON. You can do a “go” or just type “sys_start” and it will update the information in /cell/site_special.
Avoid setting the history flag on for a string variable that is being updated at a high rate, since it will result in a lot of disk activity.

There is usually a “cleanup” operation specified in /specs/usercron that determines how long the string history files are retained. You can get a quick look at this by typing “crontab –l” or by editing the usercron spec file. Most cells save the files for 14 days.

The “delta_hst” application does not attempt to save the contents of PROPERTY, COMPOSITION, STATISTICAL or EMISSION variables.