--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mb_layer1_prototypes.h	Sun Mar 05 00:05:46 2017 +0000
@@ -0,0 +1,135 @@
+/*
+ * Copyright (c) 2002,2016 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.
+ */
+
+
+
+
+ /* write a modbus frame */
+ /* WARNING: when calling this function, the *frame_data buffer
+  *          must be allocated with an extra *extra_bytes
+  *          beyond those required for the frame_length.
+  *          This is because the extra bytes will be used
+  *          to store the crc before sending the frame.
+  *
+  *          The *extra_bytes value will be returned by the
+  *          modbus_init() function call.
+  */
+ /* NOTE: calling this function will flush the input stream,
+  *       which means any frames that may have arrived
+  *       but have not yet been read using modbus_read()
+  *       will be permanently lost...
+  */
+int modbus_write(int    nd,
+                 u8    *frame_data,
+                 size_t frame_length,
+                 u16    transaction_id,
+                 const struct timespec *transmit_timeout
+                );
+
+ /* read a modbus frame */
+/*
+ * The frame is read from:
+ *   -  the node descriptor nd, if nd >= 0
+ *   -  any valid and initialised node descriptor, if nd = -1
+ *      In this case, the node where the data is eventually read from
+ *      is returned in *nd.
+ *      NOTE: (only avaliable if using TCP)
+ */
+ /* NOTE: calling modbus_write() will flush the input stream,
+  *       which means any frames that may have arrived
+  *       but have not yet been read using modbus_read()
+  *       will be permanently lost...
+  *
+  * NOTE: Ususal select semantics for (a: recv_timeout == NULL) and
+  *       (b: *recv_timeout == 0) also apply.
+  *       (a) Indefinite timeout
+  *       (b) Try once, and and quit if no data available.
+  */
+ /* NOTE: send_data and send_length is used to pass to the modbus_read() function
+  *        the frame that was previously sent over the same connection (node).
+  *        This data is then allows the modbus_read() function to ignore any 
+  *        data that is read but identical to the previously sent data. This
+  *        is used when using serial ports that echoes back all the data that is 
+  *        sent out over the same serial port. When using some RS232 to RS485 
+  *        converters, this functionality is essential as not all these converters
+  *        are capable of not echoing back the sent data.
+  *       These parameters are ignored when using TCP! 
+  */
+ 
+ /* RETURNS: number of bytes read
+  *          -1 on read from file/node error
+  *          -2 on timeout
+  */
+int modbus_read(int *nd,                /* node descriptor */
+                u8 **recv_data_ptr,
+                u16 *transaction_id,
+                const u8 *send_data,
+                int send_length,      
+                const struct timespec *recv_timeout);
+
+
+ /* init the library */
+int modbus_init(int nd_count,        /* maximum number of nodes... */
+                optimization_t opt,
+                int *extra_bytes);
+
+ /* shutdown the library...*/
+int modbus_done(void);
+
+
+/* Open a node for master / slave operation.
+ * Returns the node descriptor, or -1 on error.
+ */
+int modbus_connect(node_addr_t node_addr);
+int modbus_listen(node_addr_t node_addr);
+
+/* Close a node, needs a node descriptor as argument... */
+int modbus_close(int nd);
+
+/* Tell the library that the user will probably not be communicating
+ * for some time...
+ * This will allow the library to release any resources it will not
+ * be needing during the silence.
+ * NOTE: This is onlyused by the TCP version to close down tcp connections
+ *       when the silence will going to be longer than  second.
+ */
+int modbus_silence_init(void);
+
+ /* determine the minmum acceptable timeout... */
+ /* NOTE: timeout values passed to modbus_read() lower than the value returned
+  *       by this function may result in frames being aborted midway, since they
+  *       take at least modbus_get_min_timeout() seconds to transmit.
+  */
+double modbus_get_min_timeout(int baud,
+                              int parity,
+                              int data_bits,
+                              int stop_bits);
+
+
+
+
+
+
+
+
+
+