import datetime



def after(rec, scan):    
    path = get_exec_pars().group+"/time"
    if rec.index==0:
        create_dataset(path, 's')
    time_str = str(datetime.datetime.fromtimestamp(bpm6a.timestamp/1000.0))
    append_dataset(path, time_str , type = 's')

mscan(bpm6a, bpm6a, -1, 1000.0, after_read = after)
#mscan(bpm6b, bpm6b, 5)

#tscan(bpm6a, b5, 2.0)