import  ch.psi.pshell.epics.ChannelDouble as ChannelDouble
A1 = ChannelDouble("Y pos",                  "SARUN06-DBPM070:Y-REF-FB")
S1 = ChannelDouble("Energy per pulse (uJ)",    "SARFE10-PBPG050:PHOTON-ENERGY-PER-PULSE-US")
A1.initialize()
S1.initialize()
A1_init = A1.read()
A1i    = A1_init - 0.20
A1f    = A1_init + 0.20
nstep  = 21
lat    = 1.0
nav    = 5
plt    = plot(None, title="Output")[0]
plt.clear()
plt.setStyle(plt.Style.ErrorY)
plt.addSeries(LinePlotErrorSeries("Sensor1", Color.red))

def after_sample(record, scan):
    plt.getSeries(0).appendData(record.positions[0], record.readables[0].mean, record.readables[0].stdev)
    
try:
    S1_averager = create_averager(S1, nav, lat)
    A1.write(A1i)
    time.sleep(30.0)
    r = lscan(A1, (S1_averager), A1i, A1f, nstep, latency=5.0, after_read = after_sample)
    Act1     = r.getPositions(0)
    S1mean   = [val.mean for val in r.getReadable(0)]
    S1rms    = [val.stdev for val in r.getReadable(0)]
finally:
    A1.write(A1_init)
    A1.close()
    S1.close()