Data Selection and User Defined Header.

This example starts by skipping to a selected block on the input unit 10 using MODE=30 in EPREAD. Then a further selection is made on the logical record header (looking for ID=0) using MODE=20. The data for these events are then unpacked as 16-bit words, and only the first 100 words are written to the output unit (20) and packed in 32-bits. In addition a user defined header (IH) is used where IH(1-4) are the default package header, IH(5) is the original number of data words and IH(6) the original record sequence number.

      PROGRAM EPTEST
      DIMENSION IBUF(900),IBUFO(900),IRECI(1000),IH(6)
      CALL EPINIT
 C       SET STATUS WORDS FOR INPUT
      CALL EPSETW(10,2,1000,IERR)
      IF(IERR.NE.0)STOP 1
 C--    SKIP TO BLOCK 15
    5 CALL EPREAD(10,30,NW,IRECI,IBUF,IERR)
      IF(IERR.NE.0)STOP 5
      IF(IRECI(3).LT.15)GOTO 5
 C-- READ THE RECORD HEADER AND SELECT RECORDS WITH TYPE ID=0
   50 CALL EPREAD(10,20,NW,IRECI,IBUF,IERR)
      IF(IERR.NE.0)GOTO 500
      IF(IRECI(2).NE.0)GOTO 50
      IH(6)=IRECI(4)
 C-- READ DATA OF CURRENT RECORD, UNPACK AS 16-BIT WORDS
      CALL EPREAD(10,12,NW,IRECI,IBUF,IERR)
      IF(IERR.NE.0)GOTO 500
      JJ=NW-4
      PRINT*,NW,(IRECI(I),I=1,5),(IRECI(I),I=JJ,NW)
      IH(5)=NW
 C-- WRITE AS 32-BIT WORDS
      CALL EPOUTL(20,3,6,IH,100,IRECI,IBUFO,IERR)
      IF(IERR.NE.0)GOTO 600
      GOTO 50
 C       READ ERRORS
 C         PARITY AND OTHER
  500 IF(IERR.NE.1)GOTO 50
 C         EOF
      CALL EPCLOS(20,IBUFO,IERR)
      STOP
 C       WRITE ERRORS
  600 STOP 600
      END