program pwtime

	include		'dirspec.h'
	include		'openfile.h'

	character	cFile*80
	character	cSay*6		/'pwtime'/
	character	cFmt*7		/'(F10.5)'/
	logical		bOpen, bOpenFile

	real*8		XCstart
	real*8		XCdelta
	real*8		XCend

	!-------
	! ipsg2.time contains three double precison numbers in F12.5 format:
	! Start time, increment, and end time, specified as Carrington times

	i = iFilePath(cEnvi//'temp',0,' ','ipsg2.times',cFile)

	i = OPN__TEXT+OPN__REOPEN+OPN__UNKNOWN
	bOpen = bOpenFile(i,iU,cFile,iRec)

	if (bOpen) then
	    read (iU,cFmt) XCstart
	    read (iU,cFmt) XCdelta
	    read (iU,cFmt) XCend
	    
	    iU = iFreeLun(iU)

	else
	    call Say(cSay,'W','STOP','error opening time control file for reading')	! Exit code 0

	end if

	!-------
	! ipsg2.input receives all the user input data. This file is piped into ipsg2

	i = iFilePath(cEnvi//'temp',0,' ','ipsg2.input',cFile)

	i = OPN__TEXT+OPN__REOPEN+OPN__UNKNOWN
	bOpen = bOpenFile(i,iU,cFile,iRec)

	if (bOpen) then

	    !--------
	    ! Write the input data for ipsg2 to an ascii file.
	    ! Only the Carrington start time is updated using the setting of
	    ! symbol XCstart.

	    write (iU,'(A)') 'NO'
	    write (iU,'(A)') '18'

	    write (iU,'(A)') 'both'
	    write (iU,'(A)') 'Nagoya'
	    write (iU,'(A)') 'Nagoya'

	    write (iU,'(A)') '0.3'
	    write (iU,'(A)') '1.4'

	    !------
	    ! Velocity section

	    write (iU,'(A)') 'NO'
	    write (iU,'(A)') '4'
	    write (iU,'(A)') '9'
	    write (iU,'(A)') 'all'
	    write (iU,'(A)') '5'
	    write (iU,'(A)') '180'
	    write (iU,'(A)') '90'

	    write (iU,'(A)') '400'

	    write (iU,'(A)') '37'
	    write (iU,'(A)') '19'
	    write (iU,'(A)') '31'
	    write (iU,'(A)') '1'
	    write (iU,'(A)') '0'

	    write (iU,'(A)') '-2.5'
	    write (iU,'(A)') '0.1'

	    !-------
	    ! Start Carrington variable

	    write (iU,cFmt) XCstart
	    write (iU,'(A)') '1'

	    iU = iFreeLun(iU)

	else
	    call Say(cSay,'W','STOP','Error opening user file')	! Exit code 0

	end if

	!-------
	! Update ipsg2.times for the next pass by adding XCdelta to XCstart.

	i = iFilePath(cEnvi//'temp',0,' ','ipsg2.times',cFile)

	i = OPN__TEXT+OPN__REOPEN+OPN__UNKNOWN
	bOpen = bOpenFile(i,iU,cFile,iRec)

	if (bOpen) then
	    XCstart = XCstart+XCdelta

	    write (iU,cFmt) XCstart
	    write (iU,cFmt) XCdelta
	    write (iU,cFmt) XCend
	    
	    iU = iFreeLun(iU)

	    if (XCstart .gt. XCend) call Say(cSay,'W','STOP','Stepped past end time')	! Exit code 0

	else
	    call Say(cSay,'W','STOP','error opening time control file for writing')	! Exit code 0: error

	end if

	print *, 'XCstart :', XCStart

	call Say(cSay,'S','STOP',' ')		! Exit code 1: success

	end