prefix = "S30CB09-DWSC440"
prefix = "SINDI01-DWSC090"

channels = [("m_pos", prefix+":ENC_1_BS"), 
            ("blm", "SINLH02-DBLM235:B1_LOSS")
           #("cur_cycle", prefix+":CURR_CYCL"),
           # ("scanning", prefix+":SCANNING")
           ]    



class w_pos(Readable):
    def read(self):        
        return st.getChildren()[0].take()

st = Stream("pulse_id", dispatcher)
for c in channels:
    st.addScalar(c[0], c[1], 100, 0)   
st.initialize()
st.start()


try:
    mscan (st, [w_pos()] + st.getReadables(), 10)                   
finally:
    st.close()