mbus_cmd.c

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

  return 0;
}

/*
 * MODBUS command - Function Code 03 (Read Holding Registers)
 *
 * Returns: 1 if exception code returned,
 *          0 if response received successfully,
 *         -1 in case of error.
 */
int
mbus_cmd_read_holding_registers
(
  mbus_struct *mbus,     /* Pointer to MBUS structure */
  mbus_ubyte slave_addr, /* MODBUS device address (1-247) */
  mbus_uword start_addr, /* Starting register address (0-65535) */
  mbus_uword points_num, /* Quantity of registers to read (1-65535) */
  mbus_uword *data       /* Pointer to readed data buffer */
)
{
  int rc;
  mbus_ubyte *bufptr = mbus->buf + MBUS_DATA, data_count;
  mbus_uword word_buf;
  
  MBUS_CHECK_ADDR(slave_addr, 1);
  /* make request */
  if ((rc = mbus_cmd_addr_wdata(mbus, slave_addr, 
                                MBUS_FC_READHOLDINGREGISTERS,
                                start_addr, points_num)) != 0)
    return rc;
  
  /* take bytecount divided by 2 */
  data_count = MBUS_BYTE_RD(bufptr) / 2;
  if (!data_count)
    return -1; /* invalid value of bytecount */
  /* copy received data */
  while (data_count--)
  {
    MBUS_WORD_RD(bufptr, word_buf);
    *data++ = word_buf;
  }
  return 0;
}

/*
 * MODBUS command - Function Code 05 (Force Single Coil)
 *
 * Returns: 1 if exception code returned,
 *          0 if response received successfully,
 *         -1 in case of error.
 */
int
mbus_cmd_force_single_coil
(
  mbus_struct *mbus,     /* Pointer to MBUS structure */
  mbus_ubyte slave_addr, /* MODBUS device address (0-247) */
  mbus_uword coil_addr,  /* Coil address (0-65535) */
  mbus_uword data        /* Force data */
)
{
  int rc;
  mbus_uword resp_data;
  mbus_ubyte *bufptr = mbus->buf + MBUS_DATA;

  MBUS_CHECK_ADDR(slave_addr, 0);
  /* make request */
  if((rc = mbus_cmd_addr_wdata(mbus, slave_addr, 
                               MBUS_FC_FORCESINGLECOIL,
                               coil_addr, data)) != 0)
    return rc;
  
  /* check response coil address */
  MBUS_WORD_RD(bufptr, resp_data);
  if (resp_data!= coil_addr)
    return -1; /* coil_address is incorrect */
  /* check response data */
  MBUS_WORD_RD(bufptr, resp_data);
  return (resp_data == data) ? 0 : -1;
}

/*
 * MODBUS command - Function Code 06 (Preset Single Register)
 *
 * Returns: 1 if exception code returned,
 *          0 if response received successfully,
 *         -1 in case of error.
 */
int
mbus_cmd_preset_single_register
(
  mbus_struct *mbus,        /* Pointer to MBUS structure */
  mbus_ubyte slave_addr,    /* MODBUS device address (0-247) */
  mbus_uword register_addr, /* Starting register address (0-65535) */
  mbus_uword preset_data    /* Register preset data (0-65535) */
)
{
  int rc;
  mbus_uword resp_data;
  mbus_ubyte *bufptr = mbus->buf + MBUS_DATA;
  
  MBUS_CHECK_ADDR(slave_addr, 0);
  /* make request */
  if((rc = mbus_cmd_addr_wdata(mbus, slave_addr, 
                               MBUS_FC_PRESETSINGLEREGISTER,
                               register_addr, preset_data)) != 0)
    return rc;
  
  /* check response register address */
  MBUS_WORD_RD(bufptr, resp_data);
  if (resp_data!= register_addr)
    return -1; /* register address is incorrect */
  /* check response data */
  MBUS_WORD_RD(bufptr, resp_data);
  return (resp_data == preset_data) ? 0 : -1;
}

/*
 * MODBUS command - Function Code 08 (Diagnostics)
 *
 * Returns: 1 if exception code returned,
 *          0 if response received successfully,
 *         -1 in case of error.
 */
int
mbus_cmd_diagnostics
(
  mbus_struct *mbus,      /* Pointer to MBUS structure */
  mbus_ubyte slave_addr,  /* MODBUS device address (1-247) */
  mbus_uword subfunction, /* Subfunction code (0-65535) */
  mbus_uword *data        /* Pointer to the query data
                            (replaced by response data in case of success) */
)
{
  int rc;
  mbus_uword resp_subfunction;
  mbus_ubyte *bufptr = mbus->buf + MBUS_DATA;

  MBUS_CHECK_ADDR(slave_addr, 1);
  /* make request */
  if((rc = mbus_cmd_addr_wdata(mbus, slave_addr, 
                               MBUS_FC_DIAGNOSTICS,
                               subfunction, *data)) != 0)
    return rc;

  /* check response subfunction code */ 
  MBUS_WORD_RD(bufptr, resp_subfunction);
  if (resp_subfunction != subfunction)
    return -1; /* subfunction code is incorrect */
  /* read response data */
  MBUS_WORD_RD(bufptr, *data);
  return 0;
}

/*
 * MODBUS command - Function Code 15 (Force Multiple Coils)
 *
 * Returns: 1 if exception code returned,
 *          0 if response received successfully,
 *         -1 in case of error.
 */
int
mbus_cmd_force_multiple_coils
(
  mbus_struct *mbus,     /* Pointer to MBUS structure */
  mbus_ubyte slave_addr, /* MODBUS device address (0-247) */
  mbus_uword coils_addr, /* Coils address (0-65535) */
  mbus_uword coils_num,  /* Number of coils to force (0-65535) */
  mbus_ubyte *coils_data /* Pointer to coils force data */
)
{
  int rc;
  mbus_uword resp_data;
  mbus_ubyte *bufptr = mbus->buf + MBUS_DATA;

  MBUS_CHECK_ADDR(slave_addr, 0);
  /* make request */
  if((rc = mbus_cmd_addr_mdata(mbus, 
       slave_addr, MBUS_FC_FORCEMULTIPLECOILS, 
       coils_addr, coils_data,
       0, coils_num)) != 0)
    return rc;
  
  /* check response coil address */
  MBUS_WORD_RD(bufptr, resp_data);
  if (resp_data!= coils_addr)
    return -1; /* coil_address is incorrect */
  /* check response quantity */
  MBUS_WORD_RD(bufptr, resp_data);
  return (resp_data == coils_num) ? 0 : -1;
}

/*
 * MODBUS command - Function Code 16 (Preset Multiple Registers)
 *
 * Returns: 1 if exception code returned,
 *          0 if response received successfully,
 *         -1 in case of error.
 */
int
mbus_cmd_preset_multiple_registers
(
  mbus_struct *mbus,     /* Pointer to MBUS structure */
  mbus_ubyte slave_addr, /* MODBUS device address (0-247) */
  mbus_uword start_addr, /* Registers starting address (0-65535) */
  mbus_uword points_num, /* Number of registers to preset (0-65535) */
  mbus_uword *data       /* Pointer to registers preset data */
)
{
  int rc;
  mbus_uword resp_data;
  mbus_ubyte *bufptr = mbus->buf + MBUS_DATA;
  
  MBUS_CHECK_ADDR(slave_addr, 0);
  /* make request */
  if((rc = mbus_cmd_addr_mdata(mbus, slave_addr,
                               MBUS_FC_PRESETMULTIPLEREGISTERS,
                               start_addr, (mbus_ubyte *)data,
                               1, points_num)) != 0)
    return rc;
  
  /* check response registers starting address */
  MBUS_WORD_RD(bufptr, resp_data);
  if (resp_data != start_addr)
    return -1; /*  registers address is incorrect */
  /* check response quantity */
  MBUS_WORD_RD(bufptr, resp_data);
  return (resp_data == points_num) ? 0 : -1;
}

/*
 * MODBUS command - Function Code 17 (Report Slave ID)
 * Returns: 1 if exception code returned,
 *          0 if response received successfully,
 *         -1 in case of error.
 */
int
mbus_cmd_report_slave_id
(
  mbus_struct *mbus,      /* Pointer to MBUS structure */
  mbus_ubyte slave_addr,  /* MODBUS device address (1-247) */
  mbus_ubyte *data_count, /* Readed slave ID data count */
  mbus_ubyte *slave_data  /* Pointer to readed slave ID data buffer */
)
{
  int rc;
  mbus_ubyte byte_count;
  mbus_ubyte *bufptr = mbus->buf + MBUS_DATA;
  
  MBUS_CHECK_ADDR(slave_addr, 1);
  /* make request */
  if((rc = mbus_cmd_nodata(mbus, slave_addr,
                           MBUS_FC_REPORTSLAVEID)) != 0)
    return rc;

  /* take bytecount */
  byte_count = MBUS_BYTE_RD(bufptr);
  *data_count = byte_count;
  if (!byte_count)
    return -1; /* invalid value of bytecount */
  /* copy received data */
  while (byte_count--)
    MBUS_BYTE_WR(slave_data, *bufptr++);
  return 0;
}