Modbus Protocol Libraries
  =========================

  This directory contains the libararies that implement the modbus protocol
  stack.

  This protocol has been implemented as a two layer stack. Layer two includes
  the mb_master and the mb_slave protocols. Layer one is composed of
  the mb_rtu, mb_ascii and mb_tcp protocols.

  Layer1 protocols all implement the same interface, defined in mb_layer1.h
  Layer2 protocols implement different interfaces, defined in mb_master.h
  and mb_slave.h

  Users of these libraries should only use functions defined in the layer2
  protocol header files (i.e. mb_master.h and mb_slave.h)


            ------------------------------------------
            |                    |                   |
  layer 2   |    mb_master.h     |    mb_slave.h     |
            |    mb_master.c     |    mb_slave.c     |
            |                    |                   |
            |----------------------------------------|
            |              mb_layer1.h               |
  Layer 1   |            |              |            |
            |  mb_rtu.c  |  mb_ascii.c  |  mb_tcp.c  |
            |            |              |            |
            ------------------------------------------