/* * mbus_cmd.c - MODBUS commands routines   * * Copyright (c) 2003, Victor Antonovich (avmlink@vlink.ru) *  * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: *  * - Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. *  * - Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. *  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR * A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. * * $Id: mbus_cmd.c,v 1.2 2003/09/13 16:48:03 avm Exp $ */ #include "mbus.h"#define MBUS_BYTE_WR(p, b) \          (*(p++) = (mbus_ubyte)(b))#define MBUS_BYTE_RD(p) \          ((mbus_ubyte)*(p++))#define MBUS_WORD_WR(p, w) \          do \          { MBUS_BYTE_WR(p, ((w) >> 8) & 0xff); \            MBUS_BYTE_WR(p, ((w) & 0xff)); } \          while (0)#define MBUS_WORD_RD(p, w) \          do \          { w = ((mbus_uword)*(p++) << 8) & 0xff00; \            w |= *(p++) & 0xff; } \          while (0)            #define MBUS_CHECK_ADDR(a, m) \   if ((m && !(a)) || (a) > MBUS_ADDR_MAX) return -1#define MBUS_FC_READCOILSTATUS 1#define MBUS_FC_READINPUTSTATUS 2#define MBUS_FC_READHOLDINGREGISTERS 3#define MBUS_FC_READINPUTREGISTERS 4#define MBUS_FC_FORCESINGLECOIL 5#define MBUS_FC_PRESETSINGLEREGISTER 6#define MBUS_FC_READEXCEPTIONSTATUS 7#define MBUS_FC_DIAGNOSTICS 8#define MBUS_FC_PROGRAM484 9#define MBUS_FC_POLL484 10#define MBUS_FC_FETCHCOMMEVENTCTR 11#define MBUS_FC_FETCHCOMMEVENTLOG 12#define MBUS_FC_PROGRAMCONTROLLER 13#define MBUS_FC_POLLCONTROLLER 14#define MBUS_FC_FORCEMULTIPLECOILS 15#define MBUS_FC_PRESETMULTIPLEREGISTERS 16#define MBUS_FC_REPORTSLAVEID 17                           extern int mbus_rqst(mbus_struct *mbus, mbus_ubyte len);extern void dump(mbus_ubyte *buf, mbus_ubyte len);/* internal functions prototypes */int mbus_cmd_check_response(mbus_struct *mbus,      mbus_ubyte slave_addr, mbus_ubyte funct_code);int mbus_cmd_nodata(mbus_struct *mbus,       mbus_ubyte slave_addr, mbus_ubyte funct_code);int mbus_cmd_addr_wdata(mbus_struct *mbus,       mbus_ubyte slave_addr, mbus_ubyte funct_code,      mbus_uword addr, mbus_uword data);int mbus_cmd_addr_mdata(mbus_struct *mbus,      mbus_ubyte slave_addr, mbus_ubyte funct_code,      mbus_uword addr, mbus_ubyte *data,      mbus_ubyte data_size, mbus_word data_count);/* * Check MODBUS response for errors and exception * * Returns: 1 if exception code returned, *          0 if response received successfully, *         -1 in case of error. */intmbus_cmd_check_response(  mbus_struct *mbus,     /* Pointer to MBUS structure */  mbus_ubyte slave_addr, /* MODBUS device address (1-247) */  mbus_ubyte funct_code  /* Function code (1-255) */){  mbus_ubyte resp_fc;  mbus_ubyte *bufptr = mbus->buf + MBUS_HDR_LEN;  if (MBUS_BYTE_RD(bufptr) != slave_addr)    return -1; /* error, returning */  if ((resp_fc =         MBUS_BYTE_RD(bufptr)) != funct_code)  { /* checking for exception */    if (resp_fc == (funct_code | 0x80))    { /* report about exception */      mbus->ex_code = MBUS_BYTE_RD(bufptr);      return 1;    }    else return -1; /* response is incorrect */  };  mbus->ex_code = 0;  return 0;}/* * Make OpenMODBUS request witout data field * * Returns: 1 if exception code returned, *          0 if response received successfully, *         -1 in case of error. */intmbus_cmd_nodata(  mbus_struct *mbus,     /* Pointer to MBUS structure */  mbus_ubyte slave_addr, /* MODBUS device address (0-247) */  mbus_ubyte funct_code  /* Function code (1-255) */){  mbus_ubyte *bufptr = mbus->buf + MBUS_HDR_LEN;    /* make body request */  MBUS_BYTE_WR(bufptr, slave_addr);  MBUS_BYTE_WR(bufptr, funct_code);  /* send request to the server and receive response */  return (mbus_rqst(mbus, 2) < 0) ?    -1 : mbus_cmd_check_response(mbus, slave_addr, funct_code);}/* * Make OpenMODBUS request with address and one word data * * Returns: 1 if exception code returned, *          0 if response received successfully, *         -1 in case of error. */intmbus_cmd_addr_wdata(  mbus_struct *mbus,     /* Pointer to MBUS structure */  mbus_ubyte slave_addr, /* MODBUS device address (0-247) */  mbus_ubyte funct_code, /* Function code (1-255) */  mbus_uword addr,       /* Data address (0-65535) */  mbus_uword data        /* Query data (0-65535) */){  mbus_ubyte *bufptr = mbus->buf + MBUS_HDR_LEN;    /* make body request */  MBUS_BYTE_WR(bufptr, slave_addr);  MBUS_BYTE_WR(bufptr, funct_code);  MBUS_WORD_WR(bufptr, addr);  MBUS_WORD_WR(bufptr, data);  /* send request to the server and receive response */  return (mbus_rqst(mbus, 6) < 0) ?    -1 : mbus_cmd_check_response(mbus, slave_addr, funct_code);}/* * Make OpenMODBUS request with address and multiple word data * * Returns: 1 if exception code returned, *          0 if response received successfully, *         -1 in case of error. */intmbus_cmd_addr_mdata(  mbus_struct *mbus,     /* Pointer to MBUS structure */  mbus_ubyte slave_addr, /* MODBUS device address (0-247) */  mbus_ubyte funct_code, /* Function code (1-255) */  mbus_uword addr,       /* Data address (0-65535) */  mbus_ubyte *data,      /* Pointer to the query data */  mbus_ubyte data_size,  /* 0 for coils, non-zero for registers */  mbus_word data_count   /* Number of data values */){  mbus_ubyte byte_count, counter;  mbus_ubyte *bufptr = mbus->buf + MBUS_HDR_LEN;  mbus_uword word_buf;    /* make request body */  MBUS_BYTE_WR(bufptr, slave_addr);  MBUS_BYTE_WR(bufptr, funct_code);  MBUS_WORD_WR(bufptr, addr);  MBUS_WORD_WR(bufptr, data_count);  if (data_size)    /* each data value is 16 bit length */    byte_count = (mbus_ubyte)((data_count * 2) & 0xff);  else    /* each byte consist from max. eigth coils */    byte_count = (mbus_ubyte)((data_count + 7) >> 3);  MBUS_BYTE_WR(bufptr, byte_count);  /* copy data to request */  counter = byte_count;  if (data_size)  { /* 16-bit wide data */    counter >>= 1;    while (counter--)    { /* copy data to buffer */      word_buf = *((mbus_uword *)data);      MBUS_WORD_WR(bufptr, word_buf);      data += 2;    }  }  else    /* 8-bit wide data */    while (counter--)      MBUS_BYTE_WR(bufptr, *data++);    /* send request to the server and receive response */  return (mbus_rqst(mbus, 7 + byte_count) < 0) ?    -1 : mbus_cmd_check_response(mbus, slave_addr, funct_code);}/* * MODBUS command - Function Code 01 (Read Coil Status) * * Returns: 1 if exception code returned, *          0 if response received successfully, *         -1 in case of error. */intmbus_cmd_read_coil_status(  mbus_struct *mbus,     /* Pointer to MBUS structure */  mbus_ubyte slave_addr, /* MODBUS device address (1-247) */  mbus_uword coils_addr, /* Coils address (0-65535) */  mbus_uword coils_num,  /* Number of coils to read (0-65535) */  mbus_ubyte *coils_data /* Pointer to readed data buffer */){  int rc;  mbus_ubyte *bufptr = mbus->buf + MBUS_DATA, byte_count;    MBUS_CHECK_ADDR(slave_addr, 1);  /* make request */  if ((rc = mbus_cmd_addr_wdata(mbus, slave_addr,                                MBUS_FC_READCOILSTATUS,                                coils_addr, coils_num)) != 0)    return rc;    /* take bytecount */  byte_count = MBUS_BYTE_RD(bufptr);  if (!byte_count)    return -1; /* invalid value of bytecount */  /* copy received data */  while (byte_count--)    MBUS_BYTE_WR(coils_data, *bufptr++);