AttributeError: 'NoneType' object has no attribute 'interCharTimeout'

[neerajkumarjarvis]

https://github.com/riptideio/pymodbus/blob/f0edef3071d500b7e3a987ee196c38bb79f59518/pymodbus/client/sync.py#L476

Following error is coming when i am trying to make a serial modbus connection through rtu
Please put a check None check here

self.socket.interCharTimeout = self.inter_char_timeout
AttributeError: 'NoneType' object has no attribute 'interCharTimeout'

[dhoomakethu]

what version of pyserial are you using ? Please use the template to report the issue (OS , Pymodbus etc)
Also, please refer pyserial documentation here for interCharTimeout

[neerajkumarjarvis]

Name: pymodbus
Version: 2.1.0
Summary: A fully featured modbus protocol stack in python
Home-page: https://github.com/riptideio/pymodbus/
Author: Galen Collins
Author-email: bashwork@gmail.com
License: BSD
Location: /home/user/.local/lib/python3.6/site-packages
Requires: six, pyserial

OS:
Raspberry Pi
Linux (uname -a) -> 4.15.0-43-generic #46-Ubuntu SMP Thu Dec 6 14:45:28 UTC 2018 x86_64 x86_64 x86_64 GNU/Linux

[dhoomakethu]

Could you please paste the output of pip list.

[neerajkumarjarvis]

alembic (1.0.5)
apturl (0.5.2)
asn1crypto (0.24.0)
Babel (2.4.0)
blinker (1.4)
Brlapi (0.6.6)
certifi (2018.11.29)
chardet (3.0.4)
Click (7.0)
colorama (0.3.7)
command-not-found (0.3)
cryptography (2.1.4)
cupshelpers (1.0)
defer (1.0.6)
distro-info (0.18)
Flask (1.0.2)
Flask-BabelEx (0.9.3)
Flask-Gravatar (0.4.2)
Flask-HTMLmin (1.3.2)
Flask-Login (0.4.0)
Flask-Mail (0.9.1)
Flask-Migrate (2.3.1)
Flask-Paranoid (0.2.0)
Flask-Principal (0.4.0)
Flask-Security (1.7.5)
Flask-SQLAlchemy (2.3.2)
Flask-WTF (0.14.2)
htmlmin (0.1.12)
httplib2 (0.11.3)
idna (2.8)
itsdangerous (1.1.0)
Jinja2 (2.10)
keyring (10.6.0)
keyrings.alt (3.0)
language-selector (0.1)
launchpadlib (1.10.6)
lazr.restfulclient (0.13.5)
lazr.uri (1.0.3)
louis (3.5.0)
macaroonbakery (1.1.3)
Mako (1.0.7)
MarkupSafe (1.1.0)
MinimalModbus (0.7)
mysqlclient (1.3.14)
netifaces (0.10.4)
oauth (1.0.1)
olefile (0.45.1)
paramiko (2.0.0)
passlib (1.7.1)
pexpect (4.2.1)
Pillow (5.1.0)
pip (9.0.1)
protobuf (3.0.0)
psutil (5.4.2)
psycopg2 (2.7.5)
pyasn1 (0.4.2)
pycairo (1.16.2)
pycrypto (2.6.1)
pycups (1.9.73)
pygobject (3.26.1)
pyinotify (0.9.6)
pymacaroons (0.13.0)
pymodbus (2.1.0)
PyMySQL (0.8.0)
PyNaCl (1.1.2)
pyOpenSSL (17.5.0)
pyRFC3339 (1.0)
pyserial (3.4)
python-apt (1.6.3)
python-dateutil (2.7.5)
python-debian (0.1.32)
python-editor (1.0.3)
pytz (2018.3)
pyxdg (0.25)
PyYAML (3.12)
reportlab (3.4.0)
requests (2.21.0)
requests-unixsocket (0.1.5)
SecretStorage (2.3.1)
setuptools (39.0.1)
simplejson (3.13.2)
six (1.11.0)
speedtest-cli (2.0.0)
SQLAlchemy (1.2.16)
sqlparse (0.2.4)
sshtunnel (0.1.4)
system-service (0.3)
systemd-python (234)
ubuntu-drivers-common (0.0.0)
ufw (0.35)
unattended-upgrades (0.1)
urllib3 (1.24.1)
usb-creator (0.3.3)
wadllib (1.3.2)
Werkzeug (0.14.1)
wheel (0.30.0)
WTForms (2.1)
xkit (0.0.0)
zope.interface (4.3.2)

[dhoomakethu]

I see you are using pyserial==3.4 . Which definitely has interCharTimeout.

Python 2.7.14 (default, Jan  6 2018, 12:16:16)
[GCC 4.2.1 Compatible Apple LLVM 9.0.0 (clang-900.0.39.2)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import serial
>>> serial.VERSION
'3.4'
>>> s = serial.Serial
>>> dir(s)
['BAUDRATES', 'BAUDRATE_CONSTANTS', 'BYTESIZES', 'PARITIES', 'STOPBITS', '_SAVED_SETTINGS', '__abstractmethods__', '__class__', '__delattr__', '__dict__', '__doc__', '__enter__', '__exit__', '__format__', '__getattribute__', '__hash__', '__init__', '__iter__', '__metaclass__', '__module__', '__new__', '__reduce__', '__reduce_ex__', '__repr__', '__setattr__', '__sizeof__', '__str__', '__subclasshook__', '__weakref__', '_abc_cache', '_abc_negative_cache', '_abc_negative_cache_version', '_abc_registry', '_checkClosed', '_checkReadable', '_checkSeekable', '_checkWritable', '_reconfigure_port', '_set_rs485_mode', '_set_special_baudrate', '_update_break_state', '_update_dtr_state', '_update_rts_state', 'applySettingsDict', 'apply_settings', 'baudrate', 'break_condition', 'bytesize', 'cancel_read', 'cancel_write', 'cd', 'close', 'closed', 'cts', 'dsr', 'dsrdtr', 'dtr', 'exclusive', 'fileno', 'flush', 'flushInput', 'flushOutput', 'getCD', 'getCTS', 'getDSR', 'getRI', 'getSettingsDict', 'get_settings', 'inWaiting', 'in_waiting', 'interCharTimeout', 'inter_byte_timeout', 'iread_until', 'isOpen', 'isatty', 'next', 'nonblocking', 'open', 'osx_version', 'out_waiting', 'parity', 'port', 'read', 'read_all', 'read_until', 'readable', 'readall', 'readinto', 'readline', 'readlines', 'reset_input_buffer', 'reset_output_buffer', 'ri', 'rs485_mode', 'rts', 'rtscts', 'seek', 'seekable', 'sendBreak', 'send_break', 'setDTR', 'setPort', 'setRTS', 'set_input_flow_control', 'set_output_flow_control', 'stopbits', 'tell', 'timeout', 'truncate', 'writable', 'write', 'writeTimeout', 'write_timeout', 'writelines', 'xonxoff']
>>> serial.Serial.interCharTimeout
<property object at 0x10200c418>

(pymodbus) $ workon pymodbus-py3
(pymodbus-py3) $ python
Python 3.5.2 (default, Oct 11 2016, 05:05:28)
[GCC 4.2.1 Compatible Apple LLVM 8.0.0 (clang-800.0.38)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import serial
>>> serial.VERSION
'3.4'
>>> dir(serial.Serial)
['BAUDRATES', 'BAUDRATE_CONSTANTS', 'BYTESIZES', 'PARITIES', 'STOPBITS', '_SAVED_SETTINGS', '__abstractmethods__', '__class__', '__del__', '__delattr__', '__dict__', '__dir__', '__doc__', '__enter__', '__eq__', '__exit__', '__format__', '__ge__', '__getattribute__', '__gt__', '__hash__', '__init__', '__iter__', '__le__', '__lt__', '__module__', '__ne__', '__new__', '__next__', '__reduce__', '__reduce_ex__', '__repr__', '__setattr__', '__sizeof__', '__str__', '__subclasshook__', '__weakref__', '_abc_cache', '_abc_negative_cache', '_abc_negative_cache_version', '_abc_registry', '_checkClosed', '_checkReadable', '_checkSeekable', '_checkWritable', '_reconfigure_port', '_set_rs485_mode', '_set_special_baudrate', '_update_break_state', '_update_dtr_state', '_update_rts_state', 'applySettingsDict', 'apply_settings', 'baudrate', 'break_condition', 'bytesize', 'cancel_read', 'cancel_write', 'cd', 'close', 'closed', 'cts', 'dsr', 'dsrdtr', 'dtr', 'exclusive', 'fileno', 'flush', 'flushInput', 'flushOutput', 'getCD', 'getCTS', 'getDSR', 'getRI', 'getSettingsDict', 'get_settings', 'inWaiting', 'in_waiting', 'interCharTimeout', 'inter_byte_timeout', 'iread_until', 'isOpen', 'isatty', 'nonblocking', 'open', 'osx_version', 'out_waiting', 'parity', 'port', 'read', 'read_all', 'read_until', 'readable', 'readall', 'readinto', 'readline', 'readlines', 'reset_input_buffer', 'reset_output_buffer', 'ri', 'rs485_mode', 'rts', 'rtscts', 'seek', 'seekable', 'sendBreak', 'send_break', 'setDTR', 'setPort', 'setRTS', 'set_input_flow_control', 'set_output_flow_control', 'stopbits', 'tell', 'timeout', 'truncate', 'writable', 'write', 'writeTimeout', 'write_timeout', 'writelines', 'xonxoff']
>>> serial.Serial.interCharTimeout
<property object at 0x10e420f48>

[neerajkumarjarvis]

Yes it has attributes

serial.Serial.interCharTimeout

only none check need before calling this attribute in case Serial object is not initialised
self.socket.interCharTimeout

[dhoomakethu]

A PR already is in place #354 for the same.

[dhoomakethu]

Fixed and available as part of v2.2.0rc1.
pip install pymodbus==2.2.0rc1

[programatt]

@dhoomakethu I've installed 2.2.0rc1 and getting the same error as the OP. I looked at the file in my site packages and line 488 does not check self.socket like it does in the linked PR you provided. Is 2.2.0rc1 not the right version?

/Users/programatt/code/venvs/TestModbusTk/bin/python         
/Users/programatt/code/TestModbusTk/client.py
Traceback (most recent call last):
  File "/Users/programatt/code/TestModbusTk/client.py", line 30, in <module>
    main()
  File "/Users/programatt/code/TestModbusTk/client.py", line 26, in main
    client.connect()
  File "/Users/programatt/sync.py", line 489, in connect
    self.socket.interCharTimeout = self.inter_char_timeout
AttributeError: 'NoneType' object has no attribute 'interCharTimeout'

pip list

Package    Version 
---------- --------
modbus-tk  0.5.9   
pip        19.0.1  
pymodbus   2.2.0rc1
pyserial   3.4     
setuptools 39.1.0  
six        1.11.0 

and my client code is

from pymodbus.client.sync import ModbusSerialClient
PORT = '/dev/ttys1'
def main():
    client = ModbusSerialClient(method='rtu', port=PORT, timeout=1)
    client.connect()
    print(client.read_holding_registers(1,10))

if __name__ == "__main__":
    main()

[dhoomakethu]

As a temp workaround , you can create your client s with kwarg strict=False>.
Client = ModdbusSerialClient(....,strict=False)`

[py2pi]

@programatt did you got solution. I'm struggling with same. So please help me in communicating with RS-485. I'm able to get value in modscan32 but not in Rpi.

[dhoomakethu]

@bhtakti-aatma Please refer #377 for a fix.

[py2pi]

@dhoomakethu thanks for quick response. Now I'm getting result:
False
Connection lost, Try again
but when I'm operating with another code it's giving my connection as True.
please help me to get communicated with RS-485.