subroutine creep(mn,mx,mul)
      use creep_module  
      implicit none
      integer:: mn,mx,mul  !min,max delt,  delt multiplier
      integer:: i,j,k,im,id,ix,iter,sdat(2)
      integer:: nss,opk,ipk,ocmd,noch,span
      real:: d0,d1,val,s0
      logical did_wait    !flag that bunches may be turned off
      d0=0.0 
      do i=1,3
       call fxgetn(sred,sr1,sr2,sdat) ; d0=d0+max(sdat(1),sdat(2))
       call csr_sleep(300)
      enddo
      d0=d0/3. ; d1=d0 ;  s0=secnds(0.0)
      if(d0.lt.10) then
       call say_advise('cre', 'too low ')
       stop  
      endif

      call vmgcmd(mnem,el,el,ocmd)       !starting command 
      ns=0 ; d=0 ; wei=0 ;noch=0           !clear sampl count,data,weighting
      im=-1 ; ix=1   !init scan range ;  will expand once get heading
      opk=0   !init old peak to no change
      span=nsam   ! how much history to use (only latest sample)
      do iter=1,3
       call wait_fill(did_wait)   !test that time enough remains
       if(did_wait) call bunon
       do id=im,ix
        call dxputn('search ',mnem,el,el,ocmd+id*mul)   !new command
        call csr_sleep(wait)  !device settling
        do j=1,nsam
         call csr_sleep(300)     !long enough for new data
         nss=31.and.(ns(id)+1) ; ns(id)=nss    !circular  buffer sample loc 
         call fxgetn(sred,sr1,sr2,sdat)
         d(id,nss)=max(sdat(1),sdat(2))
         wei(id,nss)=min(1.5,float(j)*.6)      !wei= count from last cmd change
         write(40,4040) mnem,el,ocmd+id,id,d(id,nss),secnds(s0)
4040     format(a,4(i6,','),f7.2,',')
         if(d(id,nss).lt.(d1/1.3)) goto 606  !curtail if drops too fast
        enddo 
606     continue
       enddo
       call decide(span,im-1,ix+1,ipk,val)  !data +/-1 from scan, return ipk+val
       d1=max(d1,val)        !allow criterion for quit to creep up
       if(ipk.eq.opk) then
        noch=noch+1
        im=ipk-1 ; ix=ipk+1
        call dxputn(' no change ',mnem,el,el,ocmd+ipk*mul)  !reset to old pk
        goto 777   !no gain , stop trying
       else
        if(ipk.gt.opk) then
         if(ipk.lt.ix) then
          im=ipk-1 ; ix=ipk+1    !stay close
         else 
          im=ipk+1 ; ix=ipk+3    !press on
         endif 
        else
         if(ipk.gt.im) then
          im=ipk-1 ; ix=ipk+1    !stay close
         else
          im=ipk-3 ; ix=ipk-1    !next range
         endif 
        endif 
        noch=0 ; opk=ipk 
        call dxputn(' improved ',mnem,el,el,ocmd+ipk*mul)  !load to new pk
       endif
       if((im.lt.mn).or.(ix.gt.mx)) return
      enddo 
777   continue
      return
      end
      subroutine fxgetn(mmm,e1,e2,dat)
      use creep_module  
      implicit none
      character*12 mmm
      integer:: e1,e2,dat(2),var(10),i,j,k
      integer:: tar(10)=[1630,70,220,280,(100,i=1,6)]
      real f,e
      if(fake_on) then
       call vmgcmd('PFN HI VOLTS',2,2,var(1))
       call vmgcmd('LRF KLY PHS ',1,1,var(2))
       call vmgcmd('INJ PRB PHAS',1,2,var(3))
       f=5000.
       do i=1,4
        e=abs(var(i)-tar(i))
        f=f*(100.-2.*e)/100.
       enddo
       dat(1)=0 ; dat(2)=f
      else
       call vxgetn(mmm,e1,e2,dat)
      endif 
      return
      end
      subroutine dxputn(str,mnem,e1,e2,vals)
      implicit none
      character*12:: mnem
      character*(*):: str
      integer:: e1,e2,vals(*)
      integer:: e
      real t
      t=secnds(0.0)
      call vxputn(mnem,e1,e2,vals)
      write(40,4040) str,mnem,e1,vals(1),t
      if(str(1:6).ne.'search') print 4040, str,mnem,e1,vals(1),t
4040  format(a,1x,a,i4,i7,f9.2)
      return
      end