"""
Modbus Device Controller
-------------------------
These are the device management handlers. They should be
maintained in the server context and the various methods
should be inserted in the correct locations.
"""
from pymodbus.constants import DeviceInformation
from pymodbus.interfaces import Singleton
from pymodbus.utilities import dict_property
from pymodbus.compat import iteritems, itervalues, izip, int2byte
from collections import OrderedDict
#---------------------------------------------------------------------------#
# Network Access Control
#---------------------------------------------------------------------------#
[docs]class ModbusAccessControl(Singleton):
'''
This is a simple implementation of a Network Management System table.
Its purpose is to control access to the server (if it is used).
We assume that if an entry is in the table, it is allowed accesses to
resources. However, if the host does not appear in the table (all
unknown hosts) its connection will simply be closed.
Since it is a singleton, only one version can possible exist and all
instances pull from here.
'''
__nmstable = [
"127.0.0.1",
]
[docs] def __iter__(self):
''' Iterater over the network access table
:returns: An iterator of the network access table
'''
return self.__nmstable.__iter__()
[docs] def __contains__(self, host):
''' Check if a host is allowed to access resources
:param host: The host to check
'''
return host in self.__nmstable
[docs] def add(self, host):
''' Add allowed host(s) from the NMS table
:param host: The host to add
'''
if not isinstance(host, list):
host = [host]
for entry in host:
if entry not in self.__nmstable:
self.__nmstable.append(entry)
[docs] def remove(self, host):
''' Remove allowed host(s) from the NMS table
:param host: The host to remove
'''
if not isinstance(host, list):
host = [host]
for entry in host:
if entry in self.__nmstable:
self.__nmstable.remove(entry)
[docs] def check(self, host):
''' Check if a host is allowed to access resources
:param host: The host to check
'''
return host in self.__nmstable
#---------------------------------------------------------------------------#
# Modbus Plus Statistics
#---------------------------------------------------------------------------#
[docs]class ModbusPlusStatistics(object):
'''
This is used to maintain the current modbus plus statistics count. As of
right now this is simply a stub to complete the modbus implementation.
For more information, see the modbus implementation guide page 87.
'''
__data = OrderedDict({
'node_type_id' : [0x00] * 2, # 00
'software_version_number' : [0x00] * 2, # 01
'network_address' : [0x00] * 2, # 02
'mac_state_variable' : [0x00] * 2, # 03
'peer_status_code' : [0x00] * 2, # 04
'token_pass_counter' : [0x00] * 2, # 05
'token_rotation_time' : [0x00] * 2, # 06
'program_master_token_failed' : [0x00], # 07 hi
'data_master_token_failed' : [0x00], # 07 lo
'program_master_token_owner' : [0x00], # 08 hi
'data_master_token_owner' : [0x00], # 08 lo
'program_slave_token_owner' : [0x00], # 09 hi
'data_slave_token_owner' : [0x00], # 09 lo
'data_slave_command_transfer' : [0x00], # 10 hi
'__unused_10_lowbit' : [0x00], # 10 lo
'program_slave_command_transfer' : [0x00], # 11 hi
'program_master_rsp_transfer' : [0x00], # 11 lo
'program_slave_auto_logout' : [0x00], # 12 hi
'program_master_connect_status' : [0x00], # 12 lo
'receive_buffer_dma_overrun' : [0x00], # 13 hi
'pretransmit_deferral_error' : [0x00], # 13 lo
'frame_size_error' : [0x00], # 14 hi
'repeated_command_received' : [0x00], # 14 lo
'receiver_alignment_error' : [0x00], # 15 hi
'receiver_collision_abort_error' : [0x00], # 15 lo
'bad_packet_length_error' : [0x00], # 16 hi
'receiver_crc_error' : [0x00], # 16 lo
'transmit_buffer_dma_underrun' : [0x00], # 17 hi
'bad_link_address_error' : [0x00], # 17 lo
'bad_mac_function_code_error' : [0x00], # 18 hi
'internal_packet_length_error' : [0x00], # 18 lo
'communication_failed_error' : [0x00], # 19 hi
'communication_retries' : [0x00], # 19 lo
'no_response_error' : [0x00], # 20 hi
'good_receive_packet' : [0x00], # 20 lo
'unexpected_path_error' : [0x00], # 21 hi
'exception_response_error' : [0x00], # 21 lo
'forgotten_transaction_error' : [0x00], # 22 hi
'unexpected_response_error' : [0x00], # 22 lo
'active_station_bit_map' : [0x00] * 8, # 23-26
'token_station_bit_map' : [0x00] * 8, # 27-30
'global_data_bit_map' : [0x00] * 8, # 31-34
'receive_buffer_use_bit_map' : [0x00] * 8, # 35-37
'data_master_output_path' : [0x00] * 8, # 38-41
'data_slave_input_path' : [0x00] * 8, # 42-45
'program_master_outptu_path' : [0x00] * 8, # 46-49
'program_slave_input_path' : [0x00] * 8, # 50-53
})
[docs] def __init__(self):
'''
Initialize the modbus plus statistics with the default
information.
'''
self.reset()
[docs] def __iter__(self):
''' Iterater over the statistics
:returns: An iterator of the modbus plus statistics
'''
return iteritems(self.__data)
[docs] def reset(self):
''' This clears all of the modbus plus statistics
'''
for key in self.__data:
self.__data[key] = [0x00] * len(self.__data[key])
[docs] def summary(self):
''' Returns a summary of the modbus plus statistics
:returns: 54 16-bit words representing the status
'''
return itervalues(self.__data)
[docs] def encode(self):
''' Returns a summary of the modbus plus statistics
:returns: 54 16-bit words representing the status
'''
total, values = [], sum(self.__data.values(), [])
for c in range(0, len(values), 2):
total.append((values[c] << 8) | values[c+1])
return total
#---------------------------------------------------------------------------#
# Device Information Control
#---------------------------------------------------------------------------#
[docs]class ModbusDeviceIdentification(object):
'''
This is used to supply the device identification
for the readDeviceIdentification function
For more information read section 6.21 of the modbus
application protocol.
'''
__data = {
0x00: '', # VendorName
0x01: '', # ProductCode
0x02: '', # MajorMinorRevision
0x03: '', # VendorUrl
0x04: '', # ProductName
0x05: '', # ModelName
0x06: '', # UserApplicationName
0x07: '', # reserved
0x08: '', # reserved
# 0x80 -> 0xFF are private
}
__names = [
'VendorName',
'ProductCode',
'MajorMinorRevision',
'VendorUrl',
'ProductName',
'ModelName',
'UserApplicationName',
]
[docs] def __init__(self, info=None):
'''
Initialize the datastore with the elements you need.
(note acceptable range is [0x00-0x06,0x80-0xFF] inclusive)
:param information: A dictionary of {int:string} of values
'''
if isinstance(info, dict):
for key in info:
if (0x06 >= key >= 0x00) or (0x80 > key > 0x08):
self.__data[key] = info[key]
[docs] def __iter__(self):
''' Iterater over the device information
:returns: An iterator of the device information
'''
return iteritems(self.__data)
[docs] def summary(self):
''' Return a summary of the main items
:returns: An dictionary of the main items
'''
return dict(zip(self.__names, itervalues(self.__data)))
[docs] def update(self, value):
''' Update the values of this identity
using another identify as the value
:param value: The value to copy values from
'''
self.__data.update(value)
[docs] def __setitem__(self, key, value):
''' Wrapper used to access the device information
:param key: The register to set
:param value: The new value for referenced register
'''
if key not in [0x07, 0x08]:
self.__data[key] = value
[docs] def __getitem__(self, key):
''' Wrapper used to access the device information
:param key: The register to read
'''
return self.__data.setdefault(key, '')
[docs] def __str__(self):
''' Build a representation of the device
:returns: A string representation of the device
'''
return "DeviceIdentity"
#-------------------------------------------------------------------------#
# Properties
#-------------------------------------------------------------------------#
VendorName = dict_property(lambda s: s.__data, 0)
ProductCode = dict_property(lambda s: s.__data, 1)
MajorMinorRevision = dict_property(lambda s: s.__data, 2)
VendorUrl = dict_property(lambda s: s.__data, 3)
ProductName = dict_property(lambda s: s.__data, 4)
ModelName = dict_property(lambda s: s.__data, 5)
UserApplicationName = dict_property(lambda s: s.__data, 6)
#---------------------------------------------------------------------------#
# Counters Handler
#---------------------------------------------------------------------------#
class ModbusCountersHandler(object):
'''
This is a helper class to simplify the properties for the counters::
0x0B 1 Return Bus Message Count
Quantity of messages that the remote
device has detected on the communications system since its
last restart, clear counters operation, or power-up. Messages
with bad CRC are not taken into account.
0x0C 2 Return Bus Communication Error Count
Quantity of CRC errors encountered by the remote device since its
last restart, clear counters operation, or power-up. In case of
an error detected on the character level, (overrun, parity error),
or in case of a message length < 3 bytes, the receiving device is
not able to calculate the CRC. In such cases, this counter is
also incremented.
0x0D 3 Return Slave Exception Error Count
Quantity of MODBUS exception error detected by the remote device
since its last restart, clear counters operation, or power-up. It
comprises also the error detected in broadcast messages even if an
exception message is not returned in this case.
Exception errors are described and listed in "MODBUS Application
Protocol Specification" document.
0xOE 4 Return Slave Message Count
Quantity of messages addressed to the remote device, including
broadcast messages, that the remote device has processed since its
last restart, clear counters operation, or power-up.
0x0F 5 Return Slave No Response Count
Quantity of messages received by the remote device for which it
returned no response (neither a normal response nor an exception
response), since its last restart, clear counters operation, or
power-up. Then, this counter counts the number of broadcast
messages it has received.
0x10 6 Return Slave NAK Count
Quantity of messages addressed to the remote device for which it
returned a Negative Acknowledge (NAK) exception response, since
its last restart, clear counters operation, or power-up. Exception
responses are described and listed in "MODBUS Application Protocol
Specification" document.
0x11 7 Return Slave Busy Count
Quantity of messages addressed to the remote device for which it
returned a Slave Device Busy exception response, since its last
restart, clear counters operation, or power-up. Exception
responses are described and listed in "MODBUS Application
Protocol Specification" document.
0x12 8 Return Bus Character Overrun Count
Quantity of messages addressed to the remote device that it could
not handle due to a character overrun condition, since its last
restart, clear counters operation, or power-up. A character
overrun is caused by data characters arriving at the port faster
than they can.
.. note:: I threw the event counter in here for convinience
'''
__data = dict([(i, 0x0000) for i in range(9)])
__names = [
'BusMessage',
'BusCommunicationError',
'SlaveExceptionError',
'SlaveMessage',
'SlaveNoResponse',
'SlaveNAK',
'SlaveBusy',
'BusCharacterOverrun'
'Event '
]
def __iter__(self):
''' Iterater over the device counters
:returns: An iterator of the device counters
'''
return izip(self.__names, itervalues(self.__data))
def update(self, values):
''' Update the values of this identity
using another identify as the value
:param values: The value to copy values from
'''
for k, v in iteritems(values):
v += self.__getattribute__(k)
self.__setattr__(k, v)
def reset(self):
''' This clears all of the system counters
'''
self.__data = dict([(i, 0x0000) for i in range(9)])
def summary(self):
''' Returns a summary of the counters current status
:returns: A byte with each bit representing each counter
'''
count, result = 0x01, 0x00
for i in itervalues(self.__data):
if i != 0x00: result |= count
count <<= 1
return result
#-------------------------------------------------------------------------#
# Properties
#-------------------------------------------------------------------------#
BusMessage = dict_property(lambda s: s.__data, 0)
BusCommunicationError = dict_property(lambda s: s.__data, 1)
BusExceptionError = dict_property(lambda s: s.__data, 2)
SlaveMessage = dict_property(lambda s: s.__data, 3)
SlaveNoResponse = dict_property(lambda s: s.__data, 4)
SlaveNAK = dict_property(lambda s: s.__data, 5)
SlaveBusy = dict_property(lambda s: s.__data, 6)
BusCharacterOverrun = dict_property(lambda s: s.__data, 7)
Event = dict_property(lambda s: s.__data, 8)
#---------------------------------------------------------------------------#
# Main server control block
#---------------------------------------------------------------------------#
[docs]class ModbusControlBlock(Singleton):
'''
This is a global singleotn that controls all system information
All activity should be logged here and all diagnostic requests
should come from here.
'''
__mode = 'ASCII'
__diagnostic = [False] * 16
__instance = None
__listen_only = False
__delimiter = '\r'
__counters = ModbusCountersHandler()
__identity = ModbusDeviceIdentification()
__plus = ModbusPlusStatistics()
__events = []
#-------------------------------------------------------------------------#
# Magic
#-------------------------------------------------------------------------#
[docs] def __str__(self):
''' Build a representation of the control block
:returns: A string representation of the control block
'''
return "ModbusControl"
[docs] def __iter__(self):
''' Iterater over the device counters
:returns: An iterator of the device counters
'''
return self.__counters.__iter__()
#-------------------------------------------------------------------------#
# Events
#-------------------------------------------------------------------------#
[docs] def addEvent(self, event):
''' Adds a new event to the event log
:param event: A new event to add to the log
'''
self.__events.insert(0, event)
self.__events = self.__events[0:64] # chomp to 64 entries
self.Counter.Event += 1
[docs] def getEvents(self):
''' Returns an encoded collection of the event log.
:returns: The encoded events packet
'''
events = [event.encode() for event in self.__events]
return b''.join(events)
[docs] def clearEvents(self):
''' Clears the current list of events
'''
self.__events = []
#-------------------------------------------------------------------------#
# Other Properties
#-------------------------------------------------------------------------#
Identity = property(lambda s: s.__identity)
Counter = property(lambda s: s.__counters)
Events = property(lambda s: s.__events)
Plus = property(lambda s: s.__plus)
[docs] def reset(self):
''' This clears all of the system counters and the
diagnostic register
'''
self.__events = []
self.__counters.reset()
self.__diagnostic = [False] * 16
#-------------------------------------------------------------------------#
# Listen Properties
#-------------------------------------------------------------------------#
[docs] def _setListenOnly(self, value):
''' This toggles the listen only status
:param value: The value to set the listen status to
'''
self.__listen_only = bool(value)
ListenOnly = property(lambda s: s.__listen_only, _setListenOnly)
#-------------------------------------------------------------------------#
# Mode Properties
#-------------------------------------------------------------------------#
[docs] def _setMode(self, mode):
''' This toggles the current serial mode
:param mode: The data transfer method in (RTU, ASCII)
'''
if mode in ['ASCII', 'RTU']:
self.__mode = mode
Mode = property(lambda s: s.__mode, _setMode)
#-------------------------------------------------------------------------#
# Delimiter Properties
#-------------------------------------------------------------------------#
[docs] def _setDelimiter(self, char):
''' This changes the serial delimiter character
:param char: The new serial delimiter character
'''
if isinstance(char, str):
self.__delimiter = char.encode()
if isinstance(char, bytes):
self.__delimiter = char
elif isinstance(char, int):
self.__delimiter = int2byte(char)
Delimiter = property(lambda s: s.__delimiter, _setDelimiter)
#-------------------------------------------------------------------------#
# Diagnostic Properties
#-------------------------------------------------------------------------#
[docs] def setDiagnostic(self, mapping):
''' This sets the value in the diagnostic register
:param mapping: Dictionary of key:value pairs to set
'''
for entry in iteritems(mapping):
if entry[0] >= 0 and entry[0] < len(self.__diagnostic):
self.__diagnostic[entry[0]] = (entry[1] != 0)
[docs] def getDiagnostic(self, bit):
''' This gets the value in the diagnostic register
:param bit: The bit to get
:returns: The current value of the requested bit
'''
try:
if bit and bit >= 0 and bit < len(self.__diagnostic):
return self.__diagnostic[bit]
except Exception:
return None
[docs] def getDiagnosticRegister(self):
''' This gets the entire diagnostic register
:returns: The diagnostic register collection
'''
return self.__diagnostic
#---------------------------------------------------------------------------#
# Exported Identifiers
#---------------------------------------------------------------------------#
__all__ = [
"ModbusAccessControl",
"ModbusPlusStatistics",
"ModbusDeviceIdentification",
"DeviceInformationFactory",
"ModbusControlBlock"
]