diff -r 000000000000 -r ae252e0fd9b8 mb_layer1_prototypes.h --- /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 . + * + * 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); + + + + + + + + + +