mbus_cmd.c

OpenMODBUS/TCP to RS-232/485 MODBUS RTU gateway librar Zhejiang Univ. Hangzhou, China Dec.2006

/*
 * mbus_cmd.c - MODBUS commands routines  
 *
 * Copyright (c) 2003, Victor Antonovich ([e-mail])
 * 
 * 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.
 */
int
mbus_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.
 */
int
mbus_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.
 */
int
mbus_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.
 */
int
mbus_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.
 */
int
mbus_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++);