README
changeset 0 ae252e0fd9b8
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/README	Sun Mar 05 00:05:46 2017 +0000
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+/*
+ * Copyright (c) 2001-2003,2016 Mario de Sousa (msousa@fe.up.pt)
+ *
+ * This file is part of the Modbus library for Beremiz and matiec.
+ *
+ * This Modbus library is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser 
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this Modbus library.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * This code is made available on the understanding that it will not be
+ * used in safety-critical situations without a full and competent review.
+ */
+
+
+
+  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
+
+  Which layer1 protocol that will be used by the program will depend on which 
+  layer1 protocol implementation is linked to the final binary/executable.
+  It is not possible to define during run-time which layer1 protocol is to
+  be used. Each compiled program can only support a single layer1 protocol.
+
+  Users of these libraries should only use functions defined in the layer2
+  protocol header files (i.e. mb_master.h and mb_slave.h)
+
+  If writing a program that will simultaneously be a master and a slave,
+  then only use the mb_slave_and_master.h header file!
+  In this case, do not forget to link the final binary to both the
+  master and slave protocol implementations (as well as the chosen
+  layer1 protocol implementation).
+
+
+
+            ------------------------------------------
+            |                    |                   |
+  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  |
+            |            |              |            |
+            ------------------------------------------