Initialisation

Any application using the PSF system must perform all access between calls to the two system routines PSF_INIT and PSF_CLOSE. The former ensures that the common block is explicitly initialised (vital for monoliths) and the latter that all memory/file resources are released by the system before the application returns control to the calling environment.

Note that the INIT and CLOSE routines, unlike most such pairs in ASTERIX subpackages, require a STATUS argument. This is for the simple reason that they can generate errors when executing.