#!/usr/bin/env python
'''
Pymodbus Server With Updating Thread
--------------------------------------------------------------------------
This is an example of having a background thread updating the
context while the server is operating. This can also be done with
a python thread::
from threading import Thread
thread = Thread(target=updating_writer, args=(context,))
thread.start()
'''
#---------------------------------------------------------------------------#
# import the modbus libraries we need
#---------------------------------------------------------------------------#
from pymodbus.server.async import StartTcpServer
from pymodbus.device import ModbusDeviceIdentification
from pymodbus.datastore import ModbusSequentialDataBlock
from pymodbus.datastore import ModbusSlaveContext, ModbusServerContext
from pymodbus.transaction import ModbusRtuFramer, ModbusAsciiFramer
#---------------------------------------------------------------------------#
# import the twisted libraries we need
#---------------------------------------------------------------------------#
from twisted.internet.task import LoopingCall
#---------------------------------------------------------------------------#
# configure the service logging
#---------------------------------------------------------------------------#
import logging
logging.basicConfig()
log = logging.getLogger()
log.setLevel(logging.DEBUG)
#---------------------------------------------------------------------------#
# define your callback process
#---------------------------------------------------------------------------#
def updating_writer(a):
''' A worker process that runs every so often and
updates live values of the context. It should be noted
that there is a race condition for the update.
:param arguments: The input arguments to the call
'''
log.debug("updating the context")
context = a[0]
register = 3
slave_id = 0x00
address = 0x10
values = context[slave_id].getValues(register, address, count=5)
values = [v + 1 for v in values]
log.debug("new values: " + str(values))
context[slave_id].setValues(register, address, values)
#---------------------------------------------------------------------------#
# initialize your data store
#---------------------------------------------------------------------------#
store = ModbusSlaveContext(
di = ModbusSequentialDataBlock(0, [17]*100),
co = ModbusSequentialDataBlock(0, [17]*100),
hr = ModbusSequentialDataBlock(0, [17]*100),
ir = ModbusSequentialDataBlock(0, [17]*100))
context = ModbusServerContext(slaves=store, single=True)
#---------------------------------------------------------------------------#
# initialize the server information
#---------------------------------------------------------------------------#
identity = ModbusDeviceIdentification()
identity.VendorName = 'pymodbus'
identity.ProductCode = 'PM'
identity.VendorUrl = 'http://github.com/bashwork/pymodbus/'
identity.ProductName = 'pymodbus Server'
identity.ModelName = 'pymodbus Server'
identity.MajorMinorRevision = '1.0'
#---------------------------------------------------------------------------#
# run the server you want
#---------------------------------------------------------------------------#
time = 5 # 5 seconds delay
loop = LoopingCall(f=updating_writer, a=(context,))
loop.start(time, now=False) # initially delay by time
StartTcpServer(context, identity=identity, address=("localhost", 5020))