# Updating Server Example

    #!/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.asynchronous 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)

    def run_updating_server():
        # ----------------------------------------------------------------------- #
        # 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))

    if __name__ == "__main__":
        run_updating_server()