FUNCTION STEP210,source_in$,date$,ts,INFO$=info$

source$ = source_in$
source$ = STRSPLIT(source$,':',/EXTRACT)

CASE source$[0] OF
    'query': retData = '^step210' 
    ELSE   : BEGIN

        startdate = TIME_DOUBLE(date$)
        enddate   = startdate + (ts * 60.)

        fileName$  = source$[1]
        savFName$ = fileName$ + '.sav'
        files     = FINDFILE(savFName$, count=numFiles)

        IF numFiles EQ 0 THEN BEGIN
            PRINT,'No previous saveset file found; creating saveset file from ASCII file.'

            ;Load data in from file.
            OPENR, unit, fileName$, /GET_LUN
            header$ = ''
            READF,unit,header$
            READF,unit,year,month,day,hour,min,second
            IF year LE 90 THEN year = year + 2000 ELSE year = year + 1900

            READF,unit,header$
            READF,unit,header$


            c   = 0LL
            sec = 0D
            bx  = 0D
            by  = 0D
            bz  = 0D

            REPEAT BEGIN
                READF,unit,sec,bx,by,bz,pulse
                dataVec = [[sec], [bx], [by], [bz]]
                IF (c NE 0 ) THEN retData = [retData, dataVec] ELSE retData = dataVec
                ++c
            ENDREP UNTIL EOF(unit)
            FREE_LUN,unit

            ;Transform time vector into epoch time.
            ;time0 = TIMEYMDHMSTOEPOCH(LONG(year),LONG(month),LONG(day),LONG(hour),LONG(min),LONG(second))
            time$ = $
                NUMSTR(year)  + '-' +        $
                NUMSTR(month) + '-' +        $
                NUMSTR(day)   + '/' +        $
                NUMSTR(hour)  + ':' +        $
                NUMSTR(min)   + ':' +        $
                NUMSTR(second)
            HELP,time$
            time0 = TIME_DOUBLE(time$)

            ;Create a 4 column array containing:
            ;       [TimeVector Bx By Bz]
            retData[*,0] = retData[*,0] + time0

            SAVE,file=savFName$,retData
        ENDIF ELSE BEGIN
            RESTORE,file=savFName$
        ENDELSE

        ;Ensure that the array only contains data within the specified time range.
        upper   = WHERE(retData[*,0] GE startdate) 
        retData = retData[upper,*]

        lower   = WHERE(retData[*,0] LE enddate)
        retData = retData[lower,*]

        ;Select Magnetometer Component
        comp$   = STRMID(source$[2],0,1,/REVERSE_OFFSET)
        retData = comp(retData,comp$)

        ;Create Information Vector
        type$ = 'mag'
        name$ = STRUPCASE(source$[1]) + ' STEP210 Mag (' + source$[2] + ')'    
        unit$ = 'nT'
        shortID$ = STRUPCASE(source$[1]) + ':' + source$[2]
        info$ = [source_in$, type$, name$, unit$, shortID$ ]

    END
ENDCASE

RETURN, retData
END