Crash when attempting to add input registers

[codar030]

First of all to thank you for your contribution. Your tutorials have helped me a lot to understand the protocol.

I am trying to replicate the same tempSensors project. I used your code for the Modbus server with a simple client code.
My problem is that I get the following error when reviewing the server query:

DEBUG:pymodbus.factory:Factory Request[ReadInputRegistersRequest: 4]
DEBUG:pymodbus.datastore.context:validate: fc-[4] address-1: count-1
DEBUG:pymodbus.datastore.context:getValues fc-[4] address-1: count-1
Unhandled Error
Traceback (most recent call last):
File "/usr/local/lib/python3.5/dist-packages/twisted/python/log.py", line 103, in callWithLogger
return callWithContext({"system": lp}, func, *args, **kw)
File "/usr/local/lib/python3.5/dist-packages/twisted/python/log.py", line 86, in callWithContext
return context.call({ILogContext: newCtx}, func, *args, **kw)
File "/usr/local/lib/python3.5/dist-packages/twisted/python/context.py", line 122, in callWithContext
return self.currentContext().callWithContext(ctx, func, *args, **kw)
File "/usr/local/lib/python3.5/dist-packages/twisted/python/context.py", line 85, in callWithContext
return func(*args,**kw)
--- ---
File "/usr/local/lib/python3.5/dist-packages/twisted/internet/posixbase.py", line 614, in _doReadOrWrite
why = selectable.doRead()
File "/usr/local/lib/python3.5/dist-packages/twisted/internet/tcp.py", line 243, in doRead
return self._dataReceived(data)
File "/usr/local/lib/python3.5/dist-packages/twisted/internet/tcp.py", line 249, in _dataReceived
rval = self.protocol.dataReceived(data)
File "/usr/local/lib/python3.5/dist-packages/pymodbus/server/asynchronous.py", line 70, in dataReceived
unit=units)
File "/usr/local/lib/python3.5/dist-packages/pymodbus/framer/socket_framer.py", line 153, in processIncomingPacket
self._process(callback)
File "/usr/local/lib/python3.5/dist-packages/pymodbus/framer/socket_framer.py", line 181, in _process
callback(result) # defer or push to a thread?
File "/usr/local/lib/python3.5/dist-packages/pymodbus/server/asynchronous.py", line 91, in _execute
self._send(response)
File "/usr/local/lib/python3.5/dist-packages/pymodbus/server/asynchronous.py", line 100, in _send
pdu = self.framer.buildPacket(message)
File "/usr/local/lib/python3.5/dist-packages/pymodbus/framer/socket_framer.py", line 206, in buildPacket
data = message.encode()
File "/usr/local/lib/python3.5/dist-packages/pymodbus/register_read_message.py", line 79, in encode
result += struct.pack('>H', register)
struct.error: required argument is not an integer

DEBUG:pymodbus.server.asynchronous:Client Disconnected: [Failure instance: Traceback: <class 'struct.error'>: required argument is not an integer.

It seems that the register_read_message method requires an integer.
I don't know if you could help me with this problem.

Thank you

the client code:

from pymodbus.client.sync import ModbusTcpClient as ModbusClient

import logging

FORMAT = ('%(asctime)-15s %(threadName)-15s '
'%(levelname)-8s %(module)-15s:%(lineno)-8s %(message)s')
logging.basicConfig(format=FORMAT)
log = logging.getLogger()
log.setLevel(logging.DEBUG)

client = ModbusClient('localhost', port=502)
connection = client.connect()
print("Connected: " + str(connection))

request = client.read_input_registers(0, 1)

if request.isError():
# handle error, log?
print('Modbus Error:', request)
else:
result = request.registers
print(result)

client.close()