The IDI routines return a non-zero status value if the routine was unable to perform its task properly; a successful operation will return a zero value. Note that the standard IDI routines (those beginning with the two character prefix II) do not use inherited status and reset the value of the status argument to IDI__OK (= 0) at the beginning of each routine. Therefore the status value should be frequently checked if the application is to trap any errors.
The routine IIDERR can be used to obtain an error message from an IDI status value. The FORTRAN error definitions are declared in the file IDI_ERR.FOR. The C error definitions are declared in the file idi_err.htxt.