src/modbus-rtu.h

   1 /*
   2  * Copyright © 2001-2011 Stéphane Raimbault <stephane.raimbault@gmail.com>
   3  *
   4  * This library is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU Lesser General Public
   6  * License as published by the Free Software Foundation; either
   7  * version 2.1 of the License, or (at your option) any later version.
   8  *
   9  * This library is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * Lesser General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU Lesser General Public
  15  * License along with this library; if not, write to the Free Software
  16  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  17  */
  18
  19 #ifndef MODBUS_RTU_H
  20 #define MODBUS_RTU_H
  21
  22 #include "modbus.h"
  23
  24 MODBUS_BEGIN_DECLS
  25
  26 /* Modbus_Application_Protocol_V1_1b.pdf Chapter 4 Section 1 Page 5
  27  * RS232 / RS485 ADU = 253 bytes + slave (1 byte) + CRC (2 bytes) = 256 bytes
  28  */
  29 #define MODBUS_RTU_MAX_ADU_LENGTH  256
  30
  31 MODBUS_API modbus_t* modbus_new_rtu(const char *device, int baud, char parity,
  32                                 int data_bit, int stop_bit);
  33
  34 #define MODBUS_RTU_RS232 0
  35 #define MODBUS_RTU_RS485 1
  36
  37 MODBUS_API int modbus_rtu_set_serial_mode(modbus_t *ctx, int mode);
  38 MODBUS_API int modbus_rtu_get_serial_mode(modbus_t *ctx);
  39
  40 #define MODBUS_RTU_RTS_NONE   0
  41 #define MODBUS_RTU_RTS_UP     1
  42 #define MODBUS_RTU_RTS_DOWN   2
  43
  44 MODBUS_API int modbus_rtu_set_rts(modbus_t *ctx, int mode);
  45 MODBUS_API int modbus_rtu_get_rts(modbus_t *ctx);
  46
  47 MODBUS_END_DECLS
  48
  49 #endif /* MODBUS_RTU_H */