Diff: ModbusSlave232.h

Revision:

0:6262fc7582a9

Child:

1:35fdc7056f66

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/ModbusSlave232.h	Thu Jul 21 19:48:35 2016 +0000
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+#ifndef MODBUS_SLAVE_232H
+#define MODBUS_SLAVE_232H
+/****************************************************************************
+ * 
+ * ModbusSlave library implementing a Modbus RTU Slave for Arduino
+ * Modified by S.Marco. mailto:sammarcoarmengol@gmail.com
+ * Based on the work published by jpmzometa at 
+ * http://sites.google.com/site/jpmzometa/arduino-mbrt
+ * 
+ * Based also on http://pcscada.com.au by P.Costigan email: phil@pcscada.com.au
+ * 
+ * These library of functions are designed to enable a program send and
+ * receive data from a device that communicates using the Modbus protocol.
+ * 
+ * Copyright (C) 2000 Philip Costigan  P.C. SCADA LINK PTY. LTD.
+ * 
+ * This file is part of ModbusSlave.
+ * 
+ * ModbusSlave is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 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 General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ * 
+ * 
+ * The functions included here have been derived from the 
+ * Modbus Specifications and Implementation Guides
+ * 
+ * http://www.modbus.org/docs/Modbus_over_serial_line_V1_02.pdf
+ * http://www.modbus.org/docs/Modbus_Application_Protocol_V1_1b.pdf
+ * http://www.modbus.org/docs/PI_MBUS_300.pdf
+ * 
+ ****************************************************************************/
+
+/****************************************************************************
+ * BEGIN MODBUS RTU SLAVE FUNCTIONS
+ ****************************************************************************/
+
+#include <inttypes.h>
+
+class ModbusSlave232 {
+	
+private:
+  unsigned char slave;
+  //char txenpin;
+
+  unsigned int crc(unsigned char *buf, unsigned char start, unsigned char cnt);
+  void build_read_packet(unsigned char function, unsigned char count, unsigned char *packet);
+  void build_write_packet(unsigned char function, unsigned int start_addr, unsigned char count, unsigned char *packet);
+  void build_write_single_packet(unsigned char function, unsigned int write_addr, unsigned int reg_val, unsigned char* packet);
+  void build_error_packet(unsigned char function,unsigned char exception, unsigned char *packet);
+  void modbus_reply(unsigned char *packet, unsigned char string_length);
+  int send_reply(unsigned char *query, unsigned char string_length);
+  int receive_request(unsigned char *received_string);
+  int modbus_request(unsigned char *data);
+  int validate_request(unsigned char *data, unsigned char length, unsigned int regs_size);
+  int write_regs(unsigned int start_addr, unsigned char *query, int *regs);
+  int preset_multiple_registers(unsigned int start_addr,unsigned char count,unsigned char *query,int *regs);
+  int read_holding_registers(unsigned int start_addr, unsigned char reg_count, int *regs);
+  int write_single_register(unsigned int write_addr, unsigned char *query, int *regs);  
+  void configure(long baud, char parity, char txenpin);
+  
+public:
+/* 
+ * configure(slave, baud, parity, txenpin)
+ *
+ * sets the communication parameters for of the serial line.
+ *
+ * slave: identification number of the slave in the Modbus network (1 to 127)
+ * baud: baudrate in bps (typical values 9600, 19200... 115200)
+ * parity: a single character sets the parity mode (character frame format): 
+ *         'n' no parity (8N1); 'e' even parity (8E1), 'o' for odd parity (8O1).
+ * txenpin: arduino pin number that controls transmision/reception
+ *        of an external half-duplex device (e.g. a RS485 interface chip).
+ *        0 or 1 disables this function (for a two-device network)
+ *        >2 for point-to-multipoint topology (e.g. several arduinos)
+ */
+  void configure(unsigned char slave, long baud, char parity);
+
+/*
+ * update(regs, regs_size)
+ * 
+ * checks if there is any valid request from the modbus master. If there is,
+ * performs the requested action
+ * 
+ * regs: an array with the holding registers. They start at address 1 (master point of view)
+ * regs_size: total number of holding registers, i.e. the size of the array regs.
+ * returns: 0 if no request from master,
+ * 	NO_REPLY (-1) if no reply is sent to the master
+ * 	an exception code (1 to 4) in case of a modbus exceptions
+ * 	the number of bytes sent as reply ( > 4) if OK.
+ */
+  int update(int *regs, unsigned int regs_size); 
+
+  // empty constructor
+  ModbusSlave232()
+  {
+  
+  }
+
+};
+
+#endif