Example of getting a high priority rate data struct 3000 seconds into
the "day of 1996" number 690.

IDL> crissymbols_define
IDL> sissymbols_define
IDL> day1996 = 690
IDL> secondsSince1996 = get_seconds_since_1996_from_day_1996(day1996)
IDL> secondsSince1996 = secondsSince1996 + 3000
IDL> structs = get_hi_rate_struct_c(secondsSince1996)
IDL> help
% At  $MAIN$                 
DAY1996         INT       =      690
SECONDSSINCE1996
                LONG      =     59532601
STRUCTS         STRUCT    = -> L1CRISHIGHPRIORITYRATE Array[2]
Compiled Procedures:
    $MAIN$  ACETIME__DEFINE         CRISSYMBOLS_DEFINE
    INITTABSEC1996      L1CRISHIGHPRIORITYRATE__DEFINE      PUSHD
    SISSYMBOLS_DEFINE
Compiled Functions:
    CVTFROMSEC1996      CVTTOSEC1996            DIRECTORY_EXISTS
    FILE_EXISTS         GENERATE_DATA_FILE_PATH
    GET_BEGIN_END_SECS_OF_STRUCT_PRIOR_TO
    GET_DATA_BLOCK_START_AND_STOP_NUMBERS
    GET_DATA_FILE_SUFFIX_FROM_STRUCT_NAME
    GET_DATA_TYPE_PERIOD_FROM_STRUCT_NAME       GET_DATE_FROM_DAY_1996
    GET_DAY_1996_FROM_DATE
    GET_DAY_1996_FROM_SECONDS_SINCE_1996        GET_FILES_STRUCT_COUNT
    GET_FIRST_DATE_OF_ARCHIVED_DATA GET_HI_RATE_STRUCT_C
    GET_INSTRUMENT_ID_FROM_STRUCT_NAME
    GET_LAST_DATE_OF_ARCHIVED_DATA
    GET_SECONDS_SINCE_1996_FROM_DAY_1996        GET_STRUCT
    GET_STRUCTS         GET_STRUCT_NAME_FROM_STRUCT
    GET_STRUCT_SIZE     GET_SUBSET_OF_DAYS_STRUCTS
    GET_TIME_STAMPS_OF_STRUCTS      STR_SEP
    ZERO_LAST_STRUCTS_IF_VALID_AT_STOP_TIME
 
IDL> print, structs
{     7462898    59532597      998797          14       27114
   0   0
}{           0           0           0
           0           0
   0   0
}
IDL> print, structs.Second1996
    59532597           0


Note that a struct array of size 2 was returned.  This is the one data
struct which was found, plus the terminal struct, identified by the
Second1996 = 0.