import ch.psi.pshell.scan.ScanAbortedException as ScanAbortedException


start = 1
end = 5
fe_slit_V_size.move(float(start))


fe_slit_V_size.moveAsync(float(end))

readback=fe_slit_V_size.getReadback()
#Execute the scan: sample undefined number of samples until a condition is met, with auto range
scan_completed=False
def after_read(record, scan):
    global scan_completed
    if abs(readback.take()-end) < 0.1:
        print "Stopping"
        scan_completed=True
        scan.abort()
try:
    r5 = mscan(readback, keithley_1a, -1, after_read=after_read, range="auto")
except ScanAbortedException as ex:
    if not scan_completed: raise