Can write to rs232 serial tool but cannot read from it

Question

I have an rs232 serial device and am trying to read and write with it using python with pyVISA. I can write my commands using "write", but I If I try to "read" or "ask", I will get a timeout error.

I can read and write for it easily through the term labview or tera, but I cannot read with python.

Here is the python code that doesn't work:

import visa as v
si = v.SerialInstrument("COM1", delay = 0.1)
si.clear()
si.timeout = 3 
si.baud_rate = 9600 
si.data_bits = 8
si.stop_bits = 1

command = '0'
while command != 'end':
    rorw = raw_input('ask, read, or write? >>')
    command = raw_input('enter command code >>')
    if rorw == 'write':
        write1 = si.write(command)
        print write1
    elif rorw == 'read':
        read1 = si.read()
        print read1
    else:
        ask1 = si.ask(command)
        print ask

Answer 1

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