IndexError: string index out of range

[dhoomakethu]

Once in a while pymodbus throw this error

File "/Users/sanjay/.virtualenvs/huduku/lib/python2.7/site-packages/pymodbus/client/sync.py", line 85, in execute
    return self.transaction.execute(request)
  File "/Users/sanjay/.virtualenvs/huduku/lib/python2.7/site-packages/pymodbus/transaction.py", line 150, in execute
    self.client.framer.processIncomingPacket(result, self.addTransaction)
  File "/Users/sanjay/.virtualenvs/huduku/lib/python2.7/site-packages/pymodbus/transaction.py", line 672, in processIncomingPacket
    self._process(callback, error=True)
  File "/Users/sanjay/.virtualenvs/huduku/lib/python2.7/site-packages/pymodbus/transaction.py", line 692, in _process
    result = self.decoder.decode(data)
  File "/Users/sanjay/.virtualenvs/huduku/lib/python2.7/site-packages/pymodbus/factory.py", line 223, in decode
    return self._helper(message)
  File "/Users/sanjay/.virtualenvs/huduku/lib/python2.7/site-packages/pymodbus/factory.py", line 245, in _helper
    response.decode(data[1:])
  File "/Users/sanjay/.virtualenvs/huduku/lib/python2.7/site-packages/pymodbus/pdu.py", line 189, in decode
    self.exception_code = byte2int(data[0])
IndexError: string index out of range

another one

File "/Users/sanjay/.virtualenvs/huduku/lib/python2.7/site-packages/pymodbus/client/sync.py", line 85, in execute
    return self.transaction.execute(request)
  File "/Users/sanjay/.virtualenvs/huduku/lib/python2.7/site-packages/pymodbus/transaction.py", line 150, in execute
    self.client.framer.processIncomingPacket(result, self.addTransaction)
  File "/Users/sanjay/.virtualenvs/huduku/lib/python2.7/site-packages/pymodbus/transaction.py", line 672, in processIncomingPacket
    self._process(callback, error=True)
  File "/Users/sanjay/.virtualenvs/huduku/lib/python2.7/site-packages/pymodbus/transaction.py", line 692, in _process
    result = self.decoder.decode(data)
  File "/Users/sanjay/.virtualenvs/huduku/lib/python2.7/site-packages/pymodbus/factory.py", line 223, in decode
    return self._helper(message)
  File "/Users/sanjay/.virtualenvs/huduku/lib/python2.7/site-packages/pymodbus/factory.py", line 245, in _helper
    response.decode(data[1:])
  File "/Users/sanjay/.virtualenvs/huduku/lib/python2.7/site-packages/pymodbus/register_read_message.py", line 87, in decode
    byte_count = byte2int(data[0])
IndexError: string index out of range

[dhoomakethu]

Not reproducicble