/* Copyright (C) 2001-2005 Stéphane Raimbault This 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 2 of the License, or (at your option) any later version. This library 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 library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. These library of functions are designed to enable a program send and receive data from a device that communicates using the Modbus protocol. */ #ifndef _MODBUS_H_ #define _MODBUS_H_ #include #include #include #define MODBUS_TCP_PORT 502 #define HEADER_LENGTH_RTU 0 #define PRESET_QUERY_SIZE_RTU 6 #define HEADER_LENGTH_TCP 6 #define PRESET_QUERY_SIZE_TCP 12 #define CHECKSUM_SIZE_RTU 2 #define CHECKSUM_SIZE_TCP 0 /* 8 + HEADER_LENGTH_TCP */ #define MIN_QUERY_SIZE 14 /* MIN_RESPONSE_LENGTH + MAX(MAX*) */ #define MAX_PACKET_SIZE 261 #define MAX_READ_STATUS 800 #define MAX_READ_HOLD_REGS 100 #define MAX_READ_INPUT_REGS 100 #define MAX_WRITE_COILS 800 #define MAX_WRITE_REGS 100 #define REPORT_SLAVE_ID_SIZE 75 /* Time out between trames in microsecond */ #define TIME_OUT_BEGIN_OF_TRAME 500000 #define TIME_OUT_END_OF_TRAME 500000 #ifndef FALSE #define FALSE 0 #endif #ifndef TRUE #define TRUE 1 #endif /* Protocol exceptions */ #define ILLEGAL_FUNCTION -0x01 #define ILLEGAL_DATA_ADDRESS -0x02 #define ILLEGAL_DATA_VALUE -0x03 #define SLAVE_DEVICE_FAILURE -0x04 #define SERVER_FAILURE -0x04 #define ACKNOWLEDGE -0x05 #define SLAVE_DEVICE_BUSY -0x06 #define SERVER_BUSY -0x06 #define NEGATIVE_ACKNOWLEDGE -0x07 #define MEMORY_PARITY_ERROR -0x08 #define GATEWAY_PROBLEM_PATH -0x0A #define GATEWAY_PROBLEM_TARGET -0x0B /* Local */ #define COMM_TIME_OUT -0x0C #define PORT_SOCKET_FAILURE -0x0D #define SELECT_FAILURE -0x0E #define TOO_MANY_DATAS -0x0F #define INVALID_CRC -0x10 #define INVALID_EXCEPTION_CODE -0x11 typedef enum { RTU, TCP } type_com_t; typedef struct _modbus_param_t { /* Communication : RTU or TCP */ type_com_t type_com; /* Device: "/dev/ttyS0" */ char device[PATH_MAX]; /* whether or not to print errors. 0=no print, 1=print */ int print_errors; /* Bauds: 19200 */ int baud_i; /* Parity: "even", "odd", "none" */ char parity[5]; /* Data bit */ int data_bit; /* Stop bit */ int stop_bit; /* Save old termios settings */ struct termios old_tios; /* Descriptor (tty or socket) */ int fd; /* Flag debug */ int debug; /* IP address */ char ip[16]; /* Header length used for offset */ int header_length; /* Checksum size RTU = 2 and TCP = 0 */ int checksum_size; } modbus_param_t; /* All functions used for sending or receiving data return : - the numbers of values (bits or word) if success (0 or more) - less than 0 for exceptions errors */ /* Reads the boolean status of coils and sets the array elements in the destination to TRUE or FALSE */ int read_coil_status(modbus_param_t *mb_param, int slave, int start_addr, int count, int *dest); /* Same as read_coil_status but reads the slaves input table */ int read_input_status(modbus_param_t *mb_param, int slave, int start_addr, int count, int *dest); /* Read the holding registers in a slave and put the data into an array */ int read_holding_registers(modbus_param_t *mb_param, int slave, int start_addr, int count, int *dest); /* Read the input registers in a slave and put the data into an array */ int read_input_registers(modbus_param_t *mb_param, int slave, int start_addr, int count, int *dest); /* Turn on or off a single coil on the slave device */ int force_single_coil(modbus_param_t *mb_param, int slave, int coil_addr, int state); /* Sets a value in one holding register in the slave device */ int preset_single_register(modbus_param_t *mb_param, int slave, int reg_addr, int value); /* Takes an array of ints and sets or resets the coils on a slave appropriatly */ int force_multiple_coils(modbus_param_t *mb_param, int slave, int start_addr, int coil_count, int *data); /* Copy the values in an array to an array on the slave */ int preset_multiple_registers(modbus_param_t *mb_param, int slave, int start_addr, int reg_count, int *data); /* Returns some useful information about the modbus controller */ int report_slave_id(modbus_param_t *mb_param, int slave, unsigned char *dest); /* Initialises a parameters structure - device : "/dev/ttyS0" - baud : 19200 - parity : "even", "odd" or "none" - data_bit : 5, 6, 7, 8 - stop_bit : 1, 2 - print_errors : 0, 1 */ void modbus_init_rtu(modbus_param_t *mb_param, char *device, int baud, char *parity, int data_bit, int stop_bit, int print_errors); /* Initialises a parameters structure for TCP - ip : "192.168.0.5" - print_errors : 0, 1 */ void modbus_init_tcp(modbus_param_t *mb_param, char *ip_address, int print_errors); /* This function sets up a serial port for RTU communications to modbus or a TCP connexion */ int modbus_connect(modbus_param_t *mb_param); /* This function closes the serial port and restores the previous port configuration or close the TCP connexion */ void modbus_close(modbus_param_t *mb_param); /* Set in debug mode */ void modbus_set_debug(modbus_param_t *mb_param, int boolean); /* Useful for a 'daemon' */ void modbus_listen_tcp(modbus_param_t *mb_param); /* Non implemented : - read_exception_status() */ /* Find out what a master is trying to ask this slave device */ int get_slave_query_tcp(modbus_param_t *mb_param, int *slave_addr, int *query, int *start_addr, int *point_count, int *data); #endif /* _MODBUS_H_ */