import ch.psi.pshell.epics.ControlledVariable as ControlledVariable
import ch.psi.pshell.epics.Camtool as Camtool

phase = ControlledVariable("Phase", "SINEG01-RSYS:SET-BEAM-PHASE", "SINEG01-RSYS:GET-BEAM-PHASE")
phase.config.minValue   =-180.0
phase.config.maxValue   = 360.0
phase.config.precision  = 3
phase.config.resolution = 1.0
phase.config.save()
phase.initialize()

kill_camtool()
check_camtool()
camtool.start("SINBD01-DSCR010")
wait_camtool_message()

x   = camtool.stream.getChild("gr_x_fit_mean")
dx  = camtool.stream.getChild("gr_x_fit_standard_deviation")

try:
    xb  = create_averager(x,  nb, -1)    # -1 event based, waits for the next value
    dxb = create_averager(dx, nb, -1)
    dxb.monitored=True     # not blocking, will return last nb values
    r = lscan(phase, [xb, dxb], start, stop, step , latency=lat)
    rf_phase = r.getPositions(0)
    E   = [energy0 * (1 + val.mean / 1e6 / disp) for val in r.getReadable(0)]
    dE  = [energy0 * (    val.mean / 1e6 / disp) for val in r.getReadable(1)]
finally:
    phase.write(phase0)
    phase.close()
    camtool.stop()   # stops camtool but does not close it camtool is a global object