import  ch.psi.pshell.epics.ChannelDouble as ChannelDouble
A1 = ChannelDouble("Current",            "S20SY02-MKDC050:I-SET")
S1 = ChannelDouble("x1",                 "S20SY02-DBPM080:X1")
S2 = ChannelDouble("y1",                 "S20SY02-DBPM080:Y1")
A1.initialize()
S1.initialize()
S2.initialize()
A1_init = A1.read()
A1i    = -2.0
A1f    = 2.0
nstep  = 21
lat    = 0.21
nav    = 10
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.values[0].mean, record.values[0].stdev)
try:
    S1_averager = create_averager(S1, nav, lat)
    S2_averager = create_averager(S2, nav, lat)
    S2_averager.monitored=True
    time.sleep(10.0)
    r = lscan(A1, (S1_averager, S2_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)]
    S2mean   = [val.mean for val in r.getReadable(1)]
    S2rmsn   = [val.stdev for val in r.getReadable(1)]
finally:
    A1.write(A1_init)
    A1.close()
    S1.close()
    S2.close()