import  ch.psi.pshell.epics.ChannelDouble as ChannelDouble
A1 = ChannelDouble("actname",   "S20SY02-MKAC040:I-SET")
S1 = ChannelDouble("sensname",      "SARFE10-PBPG050:HAMP-INTENSITY-AVG")
A1.initialize()
S1.initialize()
A1_init = A1.read()
A1i    = 244.58
A1f    = 254.82
step   = 0.5122
lat1   = 0.11
lat2   = 1.0
nav    = 300
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, lat1)
    A1.write(A1i)
    time.sleep(2.0)
    r = lscan(A1, (S1_averager), A1i, A1f, step, latency=lat2, after_read = after_sample)
    Act1     = r.getPositions(0)
finally:
    A1.write(A1_init)
    A1.close()
    S1.close()