STEPS = 10
        
class Line(ReadableArray):
    def read(self):
        r1 = cscan(fe_slit_V_ctr, (Keithley_1_raw), -0.5, 1.0 , steps=STEPS, save=False, hidden=True) 
        return r1[Keithley_1_raw]
        
    def getSize(self):
        return STEPS+1

    def getCalibration(self):
        return ArrayCalibration(0.15,-0.5)

line=Line()
set_device_alias(line, "FE scan")

lscan(fe_slit_H_ctr, line, -0.5, 1.0, 0.1, latency=1.0)