# Python Libraries pymodbus **URL:** \ **Category:** Ignition\ **Created:** [September 16, 2015, 9:19am UTC](https://forum.inductiveautomation.com/t/python-libraries-pymodbus/10473 "2015-09-16T09:19:23Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![Chris\_Taylor](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/chris_taylor/32/3315_2.png) [@Chris\_Taylor](https://forum.inductiveautomation.com/u/Chris_Taylor)\ **Post date:** [September 16, 2015, 9:19am UTC](https://forum.inductiveautomation.com/t/python-libraries-pymodbus/10473/1 "2015-09-16T09:19:23Z")
Morning all I sometimes struggle with importing Python Libraries, right now I need to do some weird ModbusTCP stuff, retrieving stored data tables, I know what to do but I can’t do it with the Modbus driver or Kepware etc. The python library pyModbus[https://github.com/bashwork/pymodbus](https://github.com/bashwork/pymodbus) looks just the job and claims it will work with any python version above 2.3 without any third party dependencies (I don’t need serial). So the question is: has anyone got it to work? I’m just trying the the basic example ` client = ModbusTcpClient('192.168.2.21') client.write_coil(1, True) result = client.read_coils(1,1) print result.bits[0] client.close()` The client is a working modbus device that will respond monitored with wireshark. I keep getting the same error [quote]Traceback (most recent call last): File “”, line 3, in File “C:\Users\Chris.ignition\cache\gw127.0.0.1\_8088\_443\_main\C0\pylib\pymodbus\client\common.py”, line 65, in write\_coil ``` return self.execute(request) ``` File “C:\Users\Chris.ignition\cache\gw127.0.0.1\_8088\_443\_main\C0\pylib\pymodbus\client\sync.py”, line 81, in execute ``` if not self.connect(): ``` File “C:\Users\Chris.ignition\cache\gw127.0.0.1\_8088\_443\_main\C0\pylib\pymodbus\client\sync.py”, line 143, in connect ``` self.socket = socket.create_connection((self.host, self.port), ``` File “C:\Users\Chris.ignition\cache\gw127.0.0.1\_8088\_443\_main\C0\pylib\pymodbus\client\sync.py”, line 143, in connect ``` self.socket = socket.create_connection((self.host, self.port), ``` TypeError: create\_connection() got an unexpected keyword argument ‘source\_address’ [/quote] now part of the ModbusTcpClient class looks like this: [code]class ModbusTcpClient(BaseModbusClient): ‘’’ Implementation of a modbus tcp client ‘’’ ``` def __init__ (self, host='127.0.0.1', port=Defaults.Port, framer=ModbusSocketFramer, **kwargs): ''' Initialize a client instance :param host: The host to connect to (default 127.0.0.1) :param port: The modbus port to connect to (default 502) :param source_address: The source address tuple to bind to (default ('', 0)) :param framer: The modbus framer to use (default ModbusSocketFramer) .. note:: The host argument will accept ipv4 and ipv6 hosts ''' self.host = host self.port = port self.source_address = kwargs.get('source_address', ('', 0)) self.socket = None BaseModbusClient. __init__ (self, framer(ClientDecoder()), **kwargs) def connect(self): ''' Connect to the modbus tcp server :returns: True if connection succeeded, False otherwise ''' if self.socket: return True try: address = (self.host, self.port) self.socket = socket.create_connection((self.host, self.port), timeout=Defaults.Timeout, source_address=self.source_address) except socket.error, msg: _logger.error('Connection to (%s, %s) failed: %s' % \ (self.host, self.port, msg)) self.close() return self.socket != None[/code] ``` line 143 is `self.socket = socket.create_connection((self.host, self.port), timeout=Defaults.Timeout, source_address=self.source_address)` I can’t see the error, its driving me nuts! I guess its back to school, again 😃 anyone feeling bored and want to tackle it, any pointers? BTW, should I suggest a fourth topic on the 3rd Party Add-ons section of the forum for this type of post? ---
**Author:** ![pdibenedetto](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/pdibenedetto/32/6364_2.png) [@pdibenedetto](https://forum.inductiveautomation.com/u/pdibenedetto)\ **Post date:** [September 16, 2015, 3:02pm UTC](https://forum.inductiveautomation.com/t/python-libraries-pymodbus/10473/2 "2015-09-16T15:02:25Z")
The error is basically tells you that there not are a “source\_address” keyword argument for the function “create\_connection”. From [here](https://github.com/bashwork/pymodbus/blob/master/pymodbus/client/sync.py) in the first line, there the following line: `import socket` which means that use the socket module of the python standard library. From [here](https://docs.python.org/2/library/socket.html), if you find the “create\_connection” function descriptions, it’s has the following “signature”: `socket.create_connection(address[, timeout[, source_address]])` but on the bottom says the next thing: [quote]Changed in version 2.7: source\_address was added.[/quote] So, maybe it’s not working with any version above 2.3 or so it seems. Hope this helps. Regards, ---
**Author:** ![Chris\_Taylor](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/chris_taylor/32/3315_2.png) [@Chris\_Taylor](https://forum.inductiveautomation.com/u/Chris_Taylor)\ **Post date:** [September 16, 2015, 3:20pm UTC](https://forum.inductiveautomation.com/t/python-libraries-pymodbus/10473/3 "2015-09-16T15:20:43Z")
pdibenedetto Thanks, that’s very useful information, I might be able to get around that. ---
**Author:** ![Chris\_Taylor](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/chris_taylor/32/3315_2.png) [@Chris\_Taylor](https://forum.inductiveautomation.com/u/Chris_Taylor)\ **Post date:** [September 16, 2015, 4:38pm UTC](https://forum.inductiveautomation.com/t/python-libraries-pymodbus/10473/4 "2015-09-16T16:38:59Z")
So deleting the keyword “source\_address” for socket.create\_connection solves the problem and makes it compatible, the basic read and writes now work thank you very much.