pro srsp_1f_plot,filename,hrec

   lun = srsp_openarc(filename,a,nrec)
   if (lun le 0) then begin
      return
   endif

   rec = hrec-1
   header = getdata(rec,a)
   date = (srsp_tl_decode(header)).date
   obseq = getdata(rec+1,a)
   psav = !p
   !p.multi=[0,1,2]

   irec = hrec+1
   data = getdata(irec,a)
   tls = srsp_tl_decode(data)
   nmax = (nrec-hrec)*124L
   time = lonarr(nmax)
   dat = lonarr(nmax)
   dat2 = lonarr(nmax)
   istart = irec
   while (tls.segmentcode eq !seg.data) do begin
      tstart = tls.msec
      k = (irec-istart)*124L
      time[k:k+123] = lindgen(124)*20 + tstart
      dat[k:k+123] = data[indgen(124)*4+17];-data[indgen(124)*4+19]
      dat2[k:k+123] = data[indgen(124)*4+18];-data[indgen(124)*4+21]
      irec = irec + 1
      data = getdata(irec,a)
      if (data[0] eq -1) then tls.segmentcode = !seg.eos else tls = srsp_tl_decode(data)
   endwhile
   free_lun,lun
   time = time[0:k+123]
   dat = dat[0:k+123]
   dat2 = dat2[0:k+123]
   utplot,time/1000.,dat,date
   utplot,time/1000.,dat2,date
   !p = psav

return
end