open_source / modbus

  /*
   * Copyright © 2001-2011 Stéphane Raimbault <stephane.raimbault@gmail.com>
   *
   * SPDX-License-Identifier: LGPL-2.1+
   */

  #ifndef MODBUS_RTU_H
  #define MODBUS_RTU_H

  
  #include "modbus.h"
  
  MODBUS_BEGIN_DECLS
  
  /* Modbus_Application_Protocol_V1_1b.pdf Chapter 4 Section 1 Page 5
   * RS232 / RS485 ADU = 253 bytes + slave (1 byte) + CRC (2 bytes) = 256 bytes
   */
  #define MODBUS_RTU_MAX_ADU_LENGTH  256
  

  //***Not part of libmodbus - rts param added for QModMaster***//
  MODBUS_API modbus_t* modbus_new_rtu(const char *device, int baud, char parity,
                                      int data_bit, int stop_bit, int rts);

  
  #define MODBUS_RTU_RS232 0
  #define MODBUS_RTU_RS485 1
  

  MODBUS_API int modbus_rtu_set_serial_mode(modbus_t *ctx, int mode);
  MODBUS_API int modbus_rtu_get_serial_mode(modbus_t *ctx);

  
  #define MODBUS_RTU_RTS_NONE   0
  #define MODBUS_RTU_RTS_UP     1
  #define MODBUS_RTU_RTS_DOWN   2
  

  MODBUS_API int modbus_rtu_set_rts(modbus_t *ctx, int mode);
  MODBUS_API int modbus_rtu_get_rts(modbus_t *ctx);

  MODBUS_API int modbus_rtu_set_custom_rts(modbus_t *ctx, void (*set_rts) (modbus_t *ctx, int on));

  MODBUS_API int modbus_rtu_set_rts_delay(modbus_t *ctx, int us);
  MODBUS_API int modbus_rtu_get_rts_delay(modbus_t *ctx);

  
  MODBUS_END_DECLS
  

  #endif /* MODBUS_RTU_H */