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/*

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 * Copyright (c) 2001-2003,2016 Mario de Sousa (msousa@fe.up.pt)

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 *

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 * This file is part of the Modbus library for Beremiz and matiec.

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 *

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 * This Modbus library is free software: you can redistribute it and/or modify

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 * it under the terms of the GNU Lesser General Public License as published by

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 * the Free Software Foundation, either version 3 of the License, or

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 * (at your option) any later version.

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 *

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 * This program is distributed in the hope that it will be useful, but

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 * WITHOUT ANY WARRANTY; without even the implied warranty of

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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser 

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 * General Public License for more details.

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 *

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 * You should have received a copy of the GNU Lesser General Public License

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 * along with this Modbus library.  If not, see <http://www.gnu.org/licenses/>.

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 *

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 * This code is made available on the understanding that it will not be

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 * used in safety-critical situations without a full and competent review.

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 */

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  Modbus Protocol Libraries

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  =========================

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  This directory contains the libararies that implement the modbus protocol

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  stack.

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  This protocol has been implemented as a two layer stack. Layer two includes

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  the mb_master and the mb_slave protocols. Layer one is composed of

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  the mb_rtu, mb_ascii and mb_tcp protocols.

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  Layer1 protocols all implement the same interface, defined in mb_layer1.h

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  Layer2 protocols implement different interfaces, defined in mb_master.h

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  and mb_slave.h

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  Which layer1 protocol that will be used by the program will depend on which 

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  layer1 protocol implementation is linked to the final binary/executable.

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  It is not possible to define during run-time which layer1 protocol is to

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  be used. Each compiled program can only support a single layer1 protocol.

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  Users of these libraries should only use functions defined in the layer2

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  protocol header files (i.e. mb_master.h and mb_slave.h)

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  If writing a program that will simultaneously be a master and a slave,

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  then only use the mb_slave_and_master.h header file!

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  In this case, do not forget to link the final binary to both the

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  master and slave protocol implementations (as well as the chosen

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  layer1 protocol implementation).

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            ------------------------------------------

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            |                    |                   |

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  layer 2   |    mb_master.h     |    mb_slave.h     |

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            |    mb_master.c     |    mb_slave.c     |

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            |                    |                   |

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            |----------------------------------------|

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            |              mb_layer1.h               |

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  Layer 1   |            |              |            |

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            |  mb_rtu.c  |  mb_ascii.c  |  mb_tcp.c  |

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            |            |              |            |

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            ------------------------------------------