1306 lines
36 KiB
C
1306 lines
36 KiB
C
/*
|
|
* Copyright © 2001-2011 Stéphane Raimbault <stephane.raimbault@gmail.com>
|
|
*
|
|
* SPDX-License-Identifier: LGPL-2.1-or-later
|
|
*/
|
|
|
|
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
#include <errno.h>
|
|
#include <fcntl.h>
|
|
#include <string.h>
|
|
#ifndef _MSC_VER
|
|
#include <unistd.h>
|
|
#endif
|
|
#include <assert.h>
|
|
|
|
#include "modbus-private.h"
|
|
|
|
#include "modbus-rtu.h"
|
|
#include "modbus-rtu-private.h"
|
|
|
|
#if HAVE_DECL_TIOCSRS485 || HAVE_DECL_TIOCM_RTS
|
|
#include <sys/ioctl.h>
|
|
#endif
|
|
|
|
#if HAVE_DECL_TIOCSRS485
|
|
#include <linux/serial.h>
|
|
#endif
|
|
|
|
/* Table of CRC values for high-order byte */
|
|
static const uint8_t table_crc_hi[] = {
|
|
0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0,
|
|
0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41,
|
|
0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0,
|
|
0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40,
|
|
0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1,
|
|
0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41,
|
|
0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1,
|
|
0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41,
|
|
0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0,
|
|
0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40,
|
|
0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1,
|
|
0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40,
|
|
0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0,
|
|
0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40,
|
|
0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0,
|
|
0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40,
|
|
0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0,
|
|
0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41,
|
|
0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0,
|
|
0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41,
|
|
0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0,
|
|
0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40,
|
|
0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1,
|
|
0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41,
|
|
0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0,
|
|
0x80, 0x41, 0x00, 0xC1, 0x81, 0x40
|
|
};
|
|
|
|
/* Table of CRC values for low-order byte */
|
|
static const uint8_t table_crc_lo[] = {
|
|
0x00, 0xC0, 0xC1, 0x01, 0xC3, 0x03, 0x02, 0xC2, 0xC6, 0x06,
|
|
0x07, 0xC7, 0x05, 0xC5, 0xC4, 0x04, 0xCC, 0x0C, 0x0D, 0xCD,
|
|
0x0F, 0xCF, 0xCE, 0x0E, 0x0A, 0xCA, 0xCB, 0x0B, 0xC9, 0x09,
|
|
0x08, 0xC8, 0xD8, 0x18, 0x19, 0xD9, 0x1B, 0xDB, 0xDA, 0x1A,
|
|
0x1E, 0xDE, 0xDF, 0x1F, 0xDD, 0x1D, 0x1C, 0xDC, 0x14, 0xD4,
|
|
0xD5, 0x15, 0xD7, 0x17, 0x16, 0xD6, 0xD2, 0x12, 0x13, 0xD3,
|
|
0x11, 0xD1, 0xD0, 0x10, 0xF0, 0x30, 0x31, 0xF1, 0x33, 0xF3,
|
|
0xF2, 0x32, 0x36, 0xF6, 0xF7, 0x37, 0xF5, 0x35, 0x34, 0xF4,
|
|
0x3C, 0xFC, 0xFD, 0x3D, 0xFF, 0x3F, 0x3E, 0xFE, 0xFA, 0x3A,
|
|
0x3B, 0xFB, 0x39, 0xF9, 0xF8, 0x38, 0x28, 0xE8, 0xE9, 0x29,
|
|
0xEB, 0x2B, 0x2A, 0xEA, 0xEE, 0x2E, 0x2F, 0xEF, 0x2D, 0xED,
|
|
0xEC, 0x2C, 0xE4, 0x24, 0x25, 0xE5, 0x27, 0xE7, 0xE6, 0x26,
|
|
0x22, 0xE2, 0xE3, 0x23, 0xE1, 0x21, 0x20, 0xE0, 0xA0, 0x60,
|
|
0x61, 0xA1, 0x63, 0xA3, 0xA2, 0x62, 0x66, 0xA6, 0xA7, 0x67,
|
|
0xA5, 0x65, 0x64, 0xA4, 0x6C, 0xAC, 0xAD, 0x6D, 0xAF, 0x6F,
|
|
0x6E, 0xAE, 0xAA, 0x6A, 0x6B, 0xAB, 0x69, 0xA9, 0xA8, 0x68,
|
|
0x78, 0xB8, 0xB9, 0x79, 0xBB, 0x7B, 0x7A, 0xBA, 0xBE, 0x7E,
|
|
0x7F, 0xBF, 0x7D, 0xBD, 0xBC, 0x7C, 0xB4, 0x74, 0x75, 0xB5,
|
|
0x77, 0xB7, 0xB6, 0x76, 0x72, 0xB2, 0xB3, 0x73, 0xB1, 0x71,
|
|
0x70, 0xB0, 0x50, 0x90, 0x91, 0x51, 0x93, 0x53, 0x52, 0x92,
|
|
0x96, 0x56, 0x57, 0x97, 0x55, 0x95, 0x94, 0x54, 0x9C, 0x5C,
|
|
0x5D, 0x9D, 0x5F, 0x9F, 0x9E, 0x5E, 0x5A, 0x9A, 0x9B, 0x5B,
|
|
0x99, 0x59, 0x58, 0x98, 0x88, 0x48, 0x49, 0x89, 0x4B, 0x8B,
|
|
0x8A, 0x4A, 0x4E, 0x8E, 0x8F, 0x4F, 0x8D, 0x4D, 0x4C, 0x8C,
|
|
0x44, 0x84, 0x85, 0x45, 0x87, 0x47, 0x46, 0x86, 0x82, 0x42,
|
|
0x43, 0x83, 0x41, 0x81, 0x80, 0x40
|
|
};
|
|
|
|
/* Define the slave ID of the remote device to talk in master mode or set the
|
|
* internal slave ID in slave mode */
|
|
static int _modbus_set_slave(modbus_t *ctx, int slave)
|
|
{
|
|
/* Broadcast address is 0 (MODBUS_BROADCAST_ADDRESS) */
|
|
if (slave >= 0 && slave <= 247) {
|
|
ctx->slave = slave;
|
|
} else {
|
|
errno = EINVAL;
|
|
return -1;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/* Builds a RTU request header */
|
|
static int _modbus_rtu_build_request_basis(modbus_t *ctx, int function,
|
|
int addr, int nb,
|
|
uint8_t *req)
|
|
{
|
|
assert(ctx->slave != -1);
|
|
req[0] = ctx->slave;
|
|
req[1] = function;
|
|
req[2] = addr >> 8;
|
|
req[3] = addr & 0x00ff;
|
|
req[4] = nb >> 8;
|
|
req[5] = nb & 0x00ff;
|
|
|
|
return _MODBUS_RTU_PRESET_REQ_LENGTH;
|
|
}
|
|
|
|
/* Builds a RTU response header */
|
|
static int _modbus_rtu_build_response_basis(sft_t *sft, uint8_t *rsp)
|
|
{
|
|
/* In this case, the slave is certainly valid because a check is already
|
|
* done in _modbus_rtu_listen */
|
|
rsp[0] = sft->slave;
|
|
rsp[1] = sft->function;
|
|
|
|
return _MODBUS_RTU_PRESET_RSP_LENGTH;
|
|
}
|
|
|
|
static uint16_t crc16(uint8_t *buffer, uint16_t buffer_length)
|
|
{
|
|
uint8_t crc_hi = 0xFF; /* high CRC byte initialized */
|
|
uint8_t crc_lo = 0xFF; /* low CRC byte initialized */
|
|
unsigned int i; /* will index into CRC lookup */
|
|
|
|
/* pass through message buffer */
|
|
while (buffer_length--) {
|
|
i = crc_lo ^ *buffer++; /* calculate the CRC */
|
|
crc_lo = crc_hi ^ table_crc_hi[i];
|
|
crc_hi = table_crc_lo[i];
|
|
}
|
|
|
|
return (crc_hi << 8 | crc_lo);
|
|
}
|
|
|
|
static int _modbus_rtu_prepare_response_tid(const uint8_t *req, int *req_length)
|
|
{
|
|
(*req_length) -= _MODBUS_RTU_CHECKSUM_LENGTH;
|
|
/* No TID */
|
|
return 0;
|
|
}
|
|
|
|
static int _modbus_rtu_send_msg_pre(uint8_t *req, int req_length)
|
|
{
|
|
uint16_t crc = crc16(req, req_length);
|
|
|
|
/* According to the MODBUS specs (p. 14), the low order byte of the CRC comes
|
|
* first in the RTU message */
|
|
req[req_length++] = crc & 0x00FF;
|
|
req[req_length++] = crc >> 8;
|
|
|
|
return req_length;
|
|
}
|
|
|
|
#if defined(_WIN32)
|
|
|
|
/* This simple implementation is sort of a substitute of the select() call,
|
|
* working this way: the win32_ser_select() call tries to read some data from
|
|
* the serial port, setting the timeout as the select() call would. Data read is
|
|
* stored into the receive buffer, that is then consumed by the win32_ser_read()
|
|
* call. So win32_ser_select() does both the event waiting and the reading,
|
|
* while win32_ser_read() only consumes the receive buffer.
|
|
*/
|
|
|
|
static void win32_ser_init(struct win32_ser *ws)
|
|
{
|
|
/* Clear everything */
|
|
memset(ws, 0x00, sizeof(struct win32_ser));
|
|
|
|
/* Set file handle to invalid */
|
|
ws->fd = INVALID_HANDLE_VALUE;
|
|
}
|
|
|
|
/* FIXME Try to remove length_to_read -> max_len argument, only used by win32 */
|
|
static int win32_ser_select(struct win32_ser *ws, int max_len,
|
|
const struct timeval *tv)
|
|
{
|
|
COMMTIMEOUTS comm_to;
|
|
unsigned int msec = 0;
|
|
|
|
/* Check if some data still in the buffer to be consumed */
|
|
if (ws->n_bytes > 0) {
|
|
return 1;
|
|
}
|
|
|
|
/* Setup timeouts like select() would do.
|
|
FIXME Please someone on Windows can look at this?
|
|
Does it possible to use WaitCommEvent?
|
|
When tv is NULL, MAXDWORD isn't infinite!
|
|
*/
|
|
if (tv == NULL) {
|
|
msec = MAXDWORD;
|
|
} else {
|
|
msec = tv->tv_sec * 1000 + tv->tv_usec / 1000;
|
|
if (msec < 1)
|
|
msec = 1;
|
|
}
|
|
|
|
comm_to.ReadIntervalTimeout = msec;
|
|
comm_to.ReadTotalTimeoutMultiplier = 0;
|
|
comm_to.ReadTotalTimeoutConstant = msec;
|
|
comm_to.WriteTotalTimeoutMultiplier = 0;
|
|
comm_to.WriteTotalTimeoutConstant = 1000;
|
|
SetCommTimeouts(ws->fd, &comm_to);
|
|
|
|
/* Read some bytes */
|
|
if ((max_len > PY_BUF_SIZE) || (max_len < 0)) {
|
|
max_len = PY_BUF_SIZE;
|
|
}
|
|
|
|
if (ReadFile(ws->fd, &ws->buf, max_len, &ws->n_bytes, NULL)) {
|
|
/* Check if some bytes available */
|
|
if (ws->n_bytes > 0) {
|
|
/* Some bytes read */
|
|
return 1;
|
|
} else {
|
|
/* Just timed out */
|
|
return 0;
|
|
}
|
|
} else {
|
|
/* Some kind of error */
|
|
return -1;
|
|
}
|
|
}
|
|
|
|
static int win32_ser_read(struct win32_ser *ws, uint8_t *p_msg,
|
|
unsigned int max_len)
|
|
{
|
|
unsigned int n = ws->n_bytes;
|
|
|
|
if (max_len < n) {
|
|
n = max_len;
|
|
}
|
|
|
|
if (n > 0) {
|
|
memcpy(p_msg, ws->buf, n);
|
|
}
|
|
|
|
ws->n_bytes -= n;
|
|
|
|
return n;
|
|
}
|
|
#endif
|
|
|
|
#if HAVE_DECL_TIOCM_RTS
|
|
static void _modbus_rtu_ioctl_rts(modbus_t *ctx, int on)
|
|
{
|
|
int fd = ctx->s;
|
|
int flags;
|
|
|
|
ioctl(fd, TIOCMGET, &flags);
|
|
if (on) {
|
|
flags |= TIOCM_RTS;
|
|
} else {
|
|
flags &= ~TIOCM_RTS;
|
|
}
|
|
ioctl(fd, TIOCMSET, &flags);
|
|
}
|
|
#endif
|
|
|
|
static ssize_t _modbus_rtu_send(modbus_t *ctx, const uint8_t *req, int req_length)
|
|
{
|
|
#if defined(_WIN32)
|
|
modbus_rtu_t *ctx_rtu = ctx->backend_data;
|
|
DWORD n_bytes = 0;
|
|
return (WriteFile(ctx_rtu->w_ser.fd, req, req_length, &n_bytes, NULL)) ? (ssize_t)n_bytes : -1;
|
|
#else
|
|
#if HAVE_DECL_TIOCM_RTS
|
|
modbus_rtu_t *ctx_rtu = ctx->backend_data;
|
|
if (ctx_rtu->rts != MODBUS_RTU_RTS_NONE) {
|
|
ssize_t size;
|
|
|
|
if (ctx->debug) {
|
|
fprintf(stderr, "Sending request using RTS signal\n");
|
|
}
|
|
|
|
ctx_rtu->set_rts(ctx, ctx_rtu->rts == MODBUS_RTU_RTS_UP);
|
|
usleep(ctx_rtu->rts_delay);
|
|
|
|
size = write(ctx->s, req, req_length);
|
|
|
|
usleep(ctx_rtu->onebyte_time * req_length + ctx_rtu->rts_delay);
|
|
ctx_rtu->set_rts(ctx, ctx_rtu->rts != MODBUS_RTU_RTS_UP);
|
|
|
|
return size;
|
|
} else {
|
|
#endif
|
|
return write(ctx->s, req, req_length);
|
|
#if HAVE_DECL_TIOCM_RTS
|
|
}
|
|
#endif
|
|
#endif
|
|
}
|
|
|
|
static int _modbus_rtu_receive(modbus_t *ctx, uint8_t *req)
|
|
{
|
|
int rc;
|
|
modbus_rtu_t *ctx_rtu = ctx->backend_data;
|
|
|
|
if (ctx_rtu->confirmation_to_ignore) {
|
|
_modbus_receive_msg(ctx, req, MSG_CONFIRMATION);
|
|
/* Ignore errors and reset the flag */
|
|
ctx_rtu->confirmation_to_ignore = FALSE;
|
|
rc = 0;
|
|
if (ctx->debug) {
|
|
printf("Confirmation to ignore\n");
|
|
}
|
|
} else {
|
|
rc = _modbus_receive_msg(ctx, req, MSG_INDICATION);
|
|
if (rc == 0) {
|
|
/* The next expected message is a confirmation to ignore */
|
|
ctx_rtu->confirmation_to_ignore = TRUE;
|
|
}
|
|
}
|
|
return rc;
|
|
}
|
|
|
|
static ssize_t _modbus_rtu_recv(modbus_t *ctx, uint8_t *rsp, int rsp_length)
|
|
{
|
|
#if defined(_WIN32)
|
|
return win32_ser_read(&((modbus_rtu_t *)ctx->backend_data)->w_ser, rsp, rsp_length);
|
|
#else
|
|
return read(ctx->s, rsp, rsp_length);
|
|
#endif
|
|
}
|
|
|
|
static int _modbus_rtu_flush(modbus_t *);
|
|
|
|
static int _modbus_rtu_pre_check_confirmation(modbus_t *ctx, const uint8_t *req,
|
|
const uint8_t *rsp, int rsp_length)
|
|
{
|
|
/* Check responding slave is the slave we requested (except for broacast
|
|
* request) */
|
|
if (req[0] != rsp[0] && req[0] != MODBUS_BROADCAST_ADDRESS) {
|
|
if (ctx->debug) {
|
|
fprintf(stderr,
|
|
"The responding slave %d isn't the requested slave %d\n",
|
|
rsp[0], req[0]);
|
|
}
|
|
errno = EMBBADSLAVE;
|
|
return -1;
|
|
} else {
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
/* The check_crc16 function shall return 0 if the message is ignored and the
|
|
message length if the CRC is valid. Otherwise it shall return -1 and set
|
|
errno to EMBBADCRC. */
|
|
static int _modbus_rtu_check_integrity(modbus_t *ctx, uint8_t *msg,
|
|
const int msg_length)
|
|
{
|
|
uint16_t crc_calculated;
|
|
uint16_t crc_received;
|
|
int slave = msg[0];
|
|
|
|
/* Filter on the Modbus unit identifier (slave) in RTU mode to avoid useless
|
|
* CRC computing. */
|
|
if (slave != ctx->slave && slave != MODBUS_BROADCAST_ADDRESS) {
|
|
if (ctx->debug) {
|
|
printf("Request for slave %d ignored (not %d)\n", slave, ctx->slave);
|
|
}
|
|
/* Following call to check_confirmation handles this error */
|
|
return 0;
|
|
}
|
|
|
|
crc_calculated = crc16(msg, msg_length - 2);
|
|
crc_received = (msg[msg_length - 1] << 8) | msg[msg_length - 2];
|
|
|
|
/* Check CRC of msg */
|
|
if (crc_calculated == crc_received) {
|
|
return msg_length;
|
|
} else {
|
|
if (ctx->debug) {
|
|
fprintf(stderr, "ERROR CRC received 0x%0X != CRC calculated 0x%0X\n",
|
|
crc_received, crc_calculated);
|
|
}
|
|
|
|
if (ctx->error_recovery & MODBUS_ERROR_RECOVERY_PROTOCOL) {
|
|
_modbus_rtu_flush(ctx);
|
|
}
|
|
errno = EMBBADCRC;
|
|
return -1;
|
|
}
|
|
}
|
|
|
|
/* Sets up a serial port for RTU communications */
|
|
static int _modbus_rtu_connect(modbus_t *ctx)
|
|
{
|
|
#if defined(_WIN32)
|
|
DCB dcb;
|
|
#else
|
|
struct termios tios;
|
|
speed_t speed;
|
|
int flags;
|
|
#endif
|
|
modbus_rtu_t *ctx_rtu = ctx->backend_data;
|
|
|
|
if (ctx->debug) {
|
|
printf("Opening %s at %d bauds (%c, %d, %d)\n",
|
|
ctx_rtu->device, ctx_rtu->baud, ctx_rtu->parity,
|
|
ctx_rtu->data_bit, ctx_rtu->stop_bit);
|
|
}
|
|
|
|
#if defined(_WIN32)
|
|
/* Some references here:
|
|
* http://msdn.microsoft.com/en-us/library/aa450602.aspx
|
|
*/
|
|
win32_ser_init(&ctx_rtu->w_ser);
|
|
|
|
/* ctx_rtu->device should contain a string like "COMxx:" xx being a decimal
|
|
* number */
|
|
ctx_rtu->w_ser.fd = CreateFileA(ctx_rtu->device,
|
|
GENERIC_READ | GENERIC_WRITE,
|
|
0,
|
|
NULL,
|
|
OPEN_EXISTING,
|
|
0,
|
|
NULL);
|
|
|
|
/* Error checking */
|
|
if (ctx_rtu->w_ser.fd == INVALID_HANDLE_VALUE) {
|
|
if (ctx->debug) {
|
|
fprintf(stderr, "ERROR Can't open the device %s (LastError %d)\n",
|
|
ctx_rtu->device, (int)GetLastError());
|
|
}
|
|
return -1;
|
|
}
|
|
|
|
/* Save params */
|
|
ctx_rtu->old_dcb.DCBlength = sizeof(DCB);
|
|
if (!GetCommState(ctx_rtu->w_ser.fd, &ctx_rtu->old_dcb)) {
|
|
if (ctx->debug) {
|
|
fprintf(stderr, "ERROR Error getting configuration (LastError %d)\n",
|
|
(int)GetLastError());
|
|
}
|
|
CloseHandle(ctx_rtu->w_ser.fd);
|
|
ctx_rtu->w_ser.fd = INVALID_HANDLE_VALUE;
|
|
return -1;
|
|
}
|
|
|
|
/* Build new configuration (starting from current settings) */
|
|
dcb = ctx_rtu->old_dcb;
|
|
|
|
/* Speed setting */
|
|
switch (ctx_rtu->baud) {
|
|
case 110:
|
|
dcb.BaudRate = CBR_110;
|
|
break;
|
|
case 300:
|
|
dcb.BaudRate = CBR_300;
|
|
break;
|
|
case 600:
|
|
dcb.BaudRate = CBR_600;
|
|
break;
|
|
case 1200:
|
|
dcb.BaudRate = CBR_1200;
|
|
break;
|
|
case 2400:
|
|
dcb.BaudRate = CBR_2400;
|
|
break;
|
|
case 4800:
|
|
dcb.BaudRate = CBR_4800;
|
|
break;
|
|
case 9600:
|
|
dcb.BaudRate = CBR_9600;
|
|
break;
|
|
case 14400:
|
|
dcb.BaudRate = CBR_14400;
|
|
break;
|
|
case 19200:
|
|
dcb.BaudRate = CBR_19200;
|
|
break;
|
|
case 38400:
|
|
dcb.BaudRate = CBR_38400;
|
|
break;
|
|
case 57600:
|
|
dcb.BaudRate = CBR_57600;
|
|
break;
|
|
case 115200:
|
|
dcb.BaudRate = CBR_115200;
|
|
break;
|
|
case 230400:
|
|
/* CBR_230400 - not defined */
|
|
dcb.BaudRate = 230400;
|
|
break;
|
|
case 250000:
|
|
dcb.BaudRate = 250000;
|
|
break;
|
|
case 256000:
|
|
dcb.BaudRate = 256000;
|
|
break;
|
|
case 460800:
|
|
dcb.BaudRate = 460800;
|
|
break;
|
|
case 500000:
|
|
dcb.BaudRate = 500000;
|
|
break;
|
|
case 921600:
|
|
dcb.BaudRate = 921600;
|
|
break;
|
|
case 1000000:
|
|
dcb.BaudRate = 1000000;
|
|
break;
|
|
default:
|
|
dcb.BaudRate = CBR_9600;
|
|
if (ctx->debug) {
|
|
fprintf(stderr, "WARNING Unknown baud rate %d for %s (B9600 used)\n",
|
|
ctx_rtu->baud, ctx_rtu->device);
|
|
}
|
|
}
|
|
|
|
/* Data bits */
|
|
switch (ctx_rtu->data_bit) {
|
|
case 5:
|
|
dcb.ByteSize = 5;
|
|
break;
|
|
case 6:
|
|
dcb.ByteSize = 6;
|
|
break;
|
|
case 7:
|
|
dcb.ByteSize = 7;
|
|
break;
|
|
case 8:
|
|
default:
|
|
dcb.ByteSize = 8;
|
|
break;
|
|
}
|
|
|
|
/* Stop bits */
|
|
if (ctx_rtu->stop_bit == 1)
|
|
dcb.StopBits = ONESTOPBIT;
|
|
else /* 2 */
|
|
dcb.StopBits = TWOSTOPBITS;
|
|
|
|
/* Parity */
|
|
if (ctx_rtu->parity == 'N') {
|
|
dcb.Parity = NOPARITY;
|
|
dcb.fParity = FALSE;
|
|
} else if (ctx_rtu->parity == 'E') {
|
|
dcb.Parity = EVENPARITY;
|
|
dcb.fParity = TRUE;
|
|
} else {
|
|
/* odd */
|
|
dcb.Parity = ODDPARITY;
|
|
dcb.fParity = TRUE;
|
|
}
|
|
|
|
/* Hardware handshaking left as default settings retrieved */
|
|
|
|
/* No software handshaking */
|
|
dcb.fTXContinueOnXoff = TRUE;
|
|
dcb.fOutX = FALSE;
|
|
dcb.fInX = FALSE;
|
|
|
|
/* Binary mode (it's the only supported on Windows anyway) */
|
|
dcb.fBinary = TRUE;
|
|
|
|
/* Don't want errors to be blocking */
|
|
dcb.fAbortOnError = FALSE;
|
|
|
|
/* Setup port */
|
|
if (!SetCommState(ctx_rtu->w_ser.fd, &dcb)) {
|
|
if (ctx->debug) {
|
|
fprintf(stderr, "ERROR Error setting new configuration (LastError %d)\n",
|
|
(int)GetLastError());
|
|
}
|
|
CloseHandle(ctx_rtu->w_ser.fd);
|
|
ctx_rtu->w_ser.fd = INVALID_HANDLE_VALUE;
|
|
return -1;
|
|
}
|
|
#else
|
|
/* The O_NOCTTY flag tells UNIX that this program doesn't want
|
|
to be the "controlling terminal" for that port. If you
|
|
don't specify this then any input (such as keyboard abort
|
|
signals and so forth) will affect your process
|
|
|
|
Timeouts are ignored in canonical input mode or when the
|
|
NDELAY option is set on the file via open or fcntl */
|
|
flags = O_RDWR | O_NOCTTY | O_NDELAY | O_EXCL;
|
|
#ifdef O_CLOEXEC
|
|
flags |= O_CLOEXEC;
|
|
#endif
|
|
|
|
ctx->s = open(ctx_rtu->device, flags);
|
|
if (ctx->s == -1) {
|
|
if (ctx->debug) {
|
|
fprintf(stderr, "ERROR Can't open the device %s (%s)\n",
|
|
ctx_rtu->device, strerror(errno));
|
|
}
|
|
return -1;
|
|
}
|
|
|
|
/* Save */
|
|
tcgetattr(ctx->s, &ctx_rtu->old_tios);
|
|
|
|
memset(&tios, 0, sizeof(struct termios));
|
|
|
|
/* C_ISPEED Input baud (new interface)
|
|
C_OSPEED Output baud (new interface)
|
|
*/
|
|
switch (ctx_rtu->baud) {
|
|
case 110:
|
|
speed = B110;
|
|
break;
|
|
case 300:
|
|
speed = B300;
|
|
break;
|
|
case 600:
|
|
speed = B600;
|
|
break;
|
|
case 1200:
|
|
speed = B1200;
|
|
break;
|
|
case 2400:
|
|
speed = B2400;
|
|
break;
|
|
case 4800:
|
|
speed = B4800;
|
|
break;
|
|
case 9600:
|
|
speed = B9600;
|
|
break;
|
|
case 19200:
|
|
speed = B19200;
|
|
break;
|
|
case 38400:
|
|
speed = B38400;
|
|
break;
|
|
#ifdef B57600
|
|
case 57600:
|
|
speed = B57600;
|
|
break;
|
|
#endif
|
|
#ifdef B115200
|
|
case 115200:
|
|
speed = B115200;
|
|
break;
|
|
#endif
|
|
#ifdef B230400
|
|
case 230400:
|
|
speed = B230400;
|
|
break;
|
|
#endif
|
|
#ifdef B460800
|
|
case 460800:
|
|
speed = B460800;
|
|
break;
|
|
#endif
|
|
#ifdef B500000
|
|
case 500000:
|
|
speed = B500000;
|
|
break;
|
|
#endif
|
|
#ifdef B576000
|
|
case 576000:
|
|
speed = B576000;
|
|
break;
|
|
#endif
|
|
#ifdef B921600
|
|
case 921600:
|
|
speed = B921600;
|
|
break;
|
|
#endif
|
|
#ifdef B1000000
|
|
case 1000000:
|
|
speed = B1000000;
|
|
break;
|
|
#endif
|
|
#ifdef B1152000
|
|
case 1152000:
|
|
speed = B1152000;
|
|
break;
|
|
#endif
|
|
#ifdef B1500000
|
|
case 1500000:
|
|
speed = B1500000;
|
|
break;
|
|
#endif
|
|
#ifdef B2500000
|
|
case 2500000:
|
|
speed = B2500000;
|
|
break;
|
|
#endif
|
|
#ifdef B3000000
|
|
case 3000000:
|
|
speed = B3000000;
|
|
break;
|
|
#endif
|
|
#ifdef B3500000
|
|
case 3500000:
|
|
speed = B3500000;
|
|
break;
|
|
#endif
|
|
#ifdef B4000000
|
|
case 4000000:
|
|
speed = B4000000;
|
|
break;
|
|
#endif
|
|
default:
|
|
speed = B9600;
|
|
if (ctx->debug) {
|
|
fprintf(stderr,
|
|
"WARNING Unknown baud rate %d for %s (B9600 used)\n",
|
|
ctx_rtu->baud, ctx_rtu->device);
|
|
}
|
|
}
|
|
|
|
/* Set the baud rate */
|
|
if ((cfsetispeed(&tios, speed) < 0) ||
|
|
(cfsetospeed(&tios, speed) < 0)) {
|
|
close(ctx->s);
|
|
ctx->s = -1;
|
|
return -1;
|
|
}
|
|
|
|
/* C_CFLAG Control options
|
|
CLOCAL Local line - do not change "owner" of port
|
|
CREAD Enable receiver
|
|
*/
|
|
tios.c_cflag |= (CREAD | CLOCAL);
|
|
/* CSIZE, HUPCL, CRTSCTS (hardware flow control) */
|
|
|
|
/* Set data bits (5, 6, 7, 8 bits)
|
|
CSIZE Bit mask for data bits
|
|
*/
|
|
tios.c_cflag &= ~CSIZE;
|
|
switch (ctx_rtu->data_bit) {
|
|
case 5:
|
|
tios.c_cflag |= CS5;
|
|
break;
|
|
case 6:
|
|
tios.c_cflag |= CS6;
|
|
break;
|
|
case 7:
|
|
tios.c_cflag |= CS7;
|
|
break;
|
|
case 8:
|
|
default:
|
|
tios.c_cflag |= CS8;
|
|
break;
|
|
}
|
|
|
|
/* Stop bit (1 or 2) */
|
|
if (ctx_rtu->stop_bit == 1)
|
|
tios.c_cflag &=~ CSTOPB;
|
|
else /* 2 */
|
|
tios.c_cflag |= CSTOPB;
|
|
|
|
/* PARENB Enable parity bit
|
|
PARODD Use odd parity instead of even */
|
|
if (ctx_rtu->parity == 'N') {
|
|
/* None */
|
|
tios.c_cflag &=~ PARENB;
|
|
} else if (ctx_rtu->parity == 'E') {
|
|
/* Even */
|
|
tios.c_cflag |= PARENB;
|
|
tios.c_cflag &=~ PARODD;
|
|
} else {
|
|
/* Odd */
|
|
tios.c_cflag |= PARENB;
|
|
tios.c_cflag |= PARODD;
|
|
}
|
|
|
|
/* Read the man page of termios if you need more information. */
|
|
|
|
/* This field isn't used on POSIX systems
|
|
tios.c_line = 0;
|
|
*/
|
|
|
|
/* C_LFLAG Line options
|
|
|
|
ISIG Enable SIGINTR, SIGSUSP, SIGDSUSP, and SIGQUIT signals
|
|
ICANON Enable canonical input (else raw)
|
|
XCASE Map uppercase \lowercase (obsolete)
|
|
ECHO Enable echoing of input characters
|
|
ECHOE Echo erase character as BS-SP-BS
|
|
ECHOK Echo NL after kill character
|
|
ECHONL Echo NL
|
|
NOFLSH Disable flushing of input buffers after
|
|
interrupt or quit characters
|
|
IEXTEN Enable extended functions
|
|
ECHOCTL Echo control characters as ^char and delete as ~?
|
|
ECHOPRT Echo erased character as character erased
|
|
ECHOKE BS-SP-BS entire line on line kill
|
|
FLUSHO Output being flushed
|
|
PENDIN Retype pending input at next read or input char
|
|
TOSTOP Send SIGTTOU for background output
|
|
|
|
Canonical input is line-oriented. Input characters are put
|
|
into a buffer which can be edited interactively by the user
|
|
until a CR (carriage return) or LF (line feed) character is
|
|
received.
|
|
|
|
Raw input is unprocessed. Input characters are passed
|
|
through exactly as they are received, when they are
|
|
received. Generally you'll deselect the ICANON, ECHO,
|
|
ECHOE, and ISIG options when using raw input
|
|
*/
|
|
|
|
/* Raw input */
|
|
tios.c_lflag &= ~(ICANON | ECHO | ECHOE | ISIG);
|
|
|
|
/* C_IFLAG Input options
|
|
|
|
Constant Description
|
|
INPCK Enable parity check
|
|
IGNPAR Ignore parity errors
|
|
PARMRK Mark parity errors
|
|
ISTRIP Strip parity bits
|
|
IXON Enable software flow control (outgoing)
|
|
IXOFF Enable software flow control (incoming)
|
|
IXANY Allow any character to start flow again
|
|
IGNBRK Ignore break condition
|
|
BRKINT Send a SIGINT when a break condition is detected
|
|
INLCR Map NL to CR
|
|
IGNCR Ignore CR
|
|
ICRNL Map CR to NL
|
|
IUCLC Map uppercase to lowercase
|
|
IMAXBEL Echo BEL on input line too long
|
|
*/
|
|
if (ctx_rtu->parity == 'N') {
|
|
/* None */
|
|
tios.c_iflag &= ~INPCK;
|
|
} else {
|
|
tios.c_iflag |= INPCK;
|
|
}
|
|
|
|
/* Software flow control is disabled */
|
|
tios.c_iflag &= ~(IXON | IXOFF | IXANY);
|
|
|
|
/* C_OFLAG Output options
|
|
OPOST Postprocess output (not set = raw output)
|
|
ONLCR Map NL to CR-NL
|
|
|
|
ONCLR ant others needs OPOST to be enabled
|
|
*/
|
|
|
|
/* Raw output */
|
|
tios.c_oflag &=~ OPOST;
|
|
|
|
/* C_CC Control characters
|
|
VMIN Minimum number of characters to read
|
|
VTIME Time to wait for data (tenths of seconds)
|
|
|
|
UNIX serial interface drivers provide the ability to
|
|
specify character and packet timeouts. Two elements of the
|
|
c_cc array are used for timeouts: VMIN and VTIME. Timeouts
|
|
are ignored in canonical input mode or when the NDELAY
|
|
option is set on the file via open or fcntl.
|
|
|
|
VMIN specifies the minimum number of characters to read. If
|
|
it is set to 0, then the VTIME value specifies the time to
|
|
wait for every character read. Note that this does not mean
|
|
that a read call for N bytes will wait for N characters to
|
|
come in. Rather, the timeout will apply to the first
|
|
character and the read call will return the number of
|
|
characters immediately available (up to the number you
|
|
request).
|
|
|
|
If VMIN is non-zero, VTIME specifies the time to wait for
|
|
the first character read. If a character is read within the
|
|
time given, any read will block (wait) until all VMIN
|
|
characters are read. That is, once the first character is
|
|
read, the serial interface driver expects to receive an
|
|
entire packet of characters (VMIN bytes total). If no
|
|
character is read within the time allowed, then the call to
|
|
read returns 0. This method allows you to tell the serial
|
|
driver you need exactly N bytes and any read call will
|
|
return 0 or N bytes. However, the timeout only applies to
|
|
the first character read, so if for some reason the driver
|
|
misses one character inside the N byte packet then the read
|
|
call could block forever waiting for additional input
|
|
characters.
|
|
|
|
VTIME specifies the amount of time to wait for incoming
|
|
characters in tenths of seconds. If VTIME is set to 0 (the
|
|
default), reads will block (wait) indefinitely unless the
|
|
NDELAY option is set on the port with open or fcntl.
|
|
*/
|
|
/* Unused because we use open with the NDELAY option */
|
|
tios.c_cc[VMIN] = 0;
|
|
tios.c_cc[VTIME] = 0;
|
|
|
|
if (tcsetattr(ctx->s, TCSANOW, &tios) < 0) {
|
|
close(ctx->s);
|
|
ctx->s = -1;
|
|
return -1;
|
|
}
|
|
#endif
|
|
|
|
return 0;
|
|
}
|
|
|
|
int modbus_rtu_set_serial_mode(modbus_t *ctx, int mode)
|
|
{
|
|
if (ctx == NULL) {
|
|
errno = EINVAL;
|
|
return -1;
|
|
}
|
|
|
|
if (ctx->backend->backend_type == _MODBUS_BACKEND_TYPE_RTU) {
|
|
#if HAVE_DECL_TIOCSRS485
|
|
modbus_rtu_t *ctx_rtu = ctx->backend_data;
|
|
struct serial_rs485 rs485conf;
|
|
|
|
if (mode == MODBUS_RTU_RS485) {
|
|
// Get
|
|
if (ioctl(ctx->s, TIOCGRS485, &rs485conf) < 0) {
|
|
return -1;
|
|
}
|
|
// Set
|
|
rs485conf.flags |= SER_RS485_ENABLED;
|
|
if (ioctl(ctx->s, TIOCSRS485, &rs485conf) < 0) {
|
|
return -1;
|
|
}
|
|
|
|
ctx_rtu->serial_mode = MODBUS_RTU_RS485;
|
|
return 0;
|
|
} else if (mode == MODBUS_RTU_RS232) {
|
|
/* Turn off RS485 mode only if required */
|
|
if (ctx_rtu->serial_mode == MODBUS_RTU_RS485) {
|
|
/* The ioctl call is avoided because it can fail on some RS232 ports */
|
|
if (ioctl(ctx->s, TIOCGRS485, &rs485conf) < 0) {
|
|
return -1;
|
|
}
|
|
rs485conf.flags &= ~SER_RS485_ENABLED;
|
|
if (ioctl(ctx->s, TIOCSRS485, &rs485conf) < 0) {
|
|
return -1;
|
|
}
|
|
}
|
|
ctx_rtu->serial_mode = MODBUS_RTU_RS232;
|
|
return 0;
|
|
}
|
|
#else
|
|
if (ctx->debug) {
|
|
fprintf(stderr, "This function isn't supported on your platform\n");
|
|
}
|
|
errno = ENOTSUP;
|
|
return -1;
|
|
#endif
|
|
}
|
|
|
|
/* Wrong backend and invalid mode specified */
|
|
errno = EINVAL;
|
|
return -1;
|
|
}
|
|
|
|
int modbus_rtu_get_serial_mode(modbus_t *ctx)
|
|
{
|
|
if (ctx == NULL) {
|
|
errno = EINVAL;
|
|
return -1;
|
|
}
|
|
|
|
if (ctx->backend->backend_type == _MODBUS_BACKEND_TYPE_RTU) {
|
|
#if HAVE_DECL_TIOCSRS485
|
|
modbus_rtu_t *ctx_rtu = ctx->backend_data;
|
|
return ctx_rtu->serial_mode;
|
|
#else
|
|
if (ctx->debug) {
|
|
fprintf(stderr, "This function isn't supported on your platform\n");
|
|
}
|
|
errno = ENOTSUP;
|
|
return -1;
|
|
#endif
|
|
} else {
|
|
errno = EINVAL;
|
|
return -1;
|
|
}
|
|
}
|
|
|
|
int modbus_rtu_get_rts(modbus_t *ctx)
|
|
{
|
|
if (ctx == NULL) {
|
|
errno = EINVAL;
|
|
return -1;
|
|
}
|
|
|
|
if (ctx->backend->backend_type == _MODBUS_BACKEND_TYPE_RTU) {
|
|
#if HAVE_DECL_TIOCM_RTS
|
|
modbus_rtu_t *ctx_rtu = ctx->backend_data;
|
|
return ctx_rtu->rts;
|
|
#else
|
|
if (ctx->debug) {
|
|
fprintf(stderr, "This function isn't supported on your platform\n");
|
|
}
|
|
errno = ENOTSUP;
|
|
return -1;
|
|
#endif
|
|
} else {
|
|
errno = EINVAL;
|
|
return -1;
|
|
}
|
|
}
|
|
|
|
int modbus_rtu_set_rts(modbus_t *ctx, int mode)
|
|
{
|
|
if (ctx == NULL) {
|
|
errno = EINVAL;
|
|
return -1;
|
|
}
|
|
|
|
if (ctx->backend->backend_type == _MODBUS_BACKEND_TYPE_RTU) {
|
|
#if HAVE_DECL_TIOCM_RTS
|
|
modbus_rtu_t *ctx_rtu = ctx->backend_data;
|
|
|
|
if (mode == MODBUS_RTU_RTS_NONE || mode == MODBUS_RTU_RTS_UP ||
|
|
mode == MODBUS_RTU_RTS_DOWN) {
|
|
ctx_rtu->rts = mode;
|
|
|
|
/* Set the RTS bit in order to not reserve the RS485 bus */
|
|
ctx_rtu->set_rts(ctx, ctx_rtu->rts != MODBUS_RTU_RTS_UP);
|
|
|
|
return 0;
|
|
} else {
|
|
errno = EINVAL;
|
|
return -1;
|
|
}
|
|
#else
|
|
if (ctx->debug) {
|
|
fprintf(stderr, "This function isn't supported on your platform\n");
|
|
}
|
|
errno = ENOTSUP;
|
|
return -1;
|
|
#endif
|
|
}
|
|
/* Wrong backend or invalid mode specified */
|
|
errno = EINVAL;
|
|
return -1;
|
|
}
|
|
|
|
int modbus_rtu_set_custom_rts(modbus_t *ctx, void (*set_rts) (modbus_t *ctx, int on))
|
|
{
|
|
if (ctx == NULL) {
|
|
errno = EINVAL;
|
|
return -1;
|
|
}
|
|
|
|
if (ctx->backend->backend_type == _MODBUS_BACKEND_TYPE_RTU) {
|
|
#if HAVE_DECL_TIOCM_RTS
|
|
modbus_rtu_t *ctx_rtu = ctx->backend_data;
|
|
ctx_rtu->set_rts = set_rts;
|
|
return 0;
|
|
#else
|
|
if (ctx->debug) {
|
|
fprintf(stderr, "This function isn't supported on your platform\n");
|
|
}
|
|
errno = ENOTSUP;
|
|
return -1;
|
|
#endif
|
|
} else {
|
|
errno = EINVAL;
|
|
return -1;
|
|
}
|
|
}
|
|
|
|
int modbus_rtu_get_rts_delay(modbus_t *ctx)
|
|
{
|
|
if (ctx == NULL) {
|
|
errno = EINVAL;
|
|
return -1;
|
|
}
|
|
|
|
if (ctx->backend->backend_type == _MODBUS_BACKEND_TYPE_RTU) {
|
|
#if HAVE_DECL_TIOCM_RTS
|
|
modbus_rtu_t *ctx_rtu;
|
|
ctx_rtu = (modbus_rtu_t *)ctx->backend_data;
|
|
return ctx_rtu->rts_delay;
|
|
#else
|
|
if (ctx->debug) {
|
|
fprintf(stderr, "This function isn't supported on your platform\n");
|
|
}
|
|
errno = ENOTSUP;
|
|
return -1;
|
|
#endif
|
|
} else {
|
|
errno = EINVAL;
|
|
return -1;
|
|
}
|
|
}
|
|
|
|
int modbus_rtu_set_rts_delay(modbus_t *ctx, int us)
|
|
{
|
|
if (ctx == NULL || us < 0) {
|
|
errno = EINVAL;
|
|
return -1;
|
|
}
|
|
|
|
if (ctx->backend->backend_type == _MODBUS_BACKEND_TYPE_RTU) {
|
|
#if HAVE_DECL_TIOCM_RTS
|
|
modbus_rtu_t *ctx_rtu;
|
|
ctx_rtu = (modbus_rtu_t *)ctx->backend_data;
|
|
ctx_rtu->rts_delay = us;
|
|
return 0;
|
|
#else
|
|
if (ctx->debug) {
|
|
fprintf(stderr, "This function isn't supported on your platform\n");
|
|
}
|
|
errno = ENOTSUP;
|
|
return -1;
|
|
#endif
|
|
} else {
|
|
errno = EINVAL;
|
|
return -1;
|
|
}
|
|
}
|
|
|
|
static void _modbus_rtu_close(modbus_t *ctx)
|
|
{
|
|
/* Restore line settings and close file descriptor in RTU mode */
|
|
modbus_rtu_t *ctx_rtu = ctx->backend_data;
|
|
|
|
#if defined(_WIN32)
|
|
/* Revert settings */
|
|
if (!SetCommState(ctx_rtu->w_ser.fd, &ctx_rtu->old_dcb) && ctx->debug) {
|
|
fprintf(stderr, "ERROR Couldn't revert to configuration (LastError %d)\n",
|
|
(int)GetLastError());
|
|
}
|
|
|
|
if (!CloseHandle(ctx_rtu->w_ser.fd) && ctx->debug) {
|
|
fprintf(stderr, "ERROR Error while closing handle (LastError %d)\n",
|
|
(int)GetLastError());
|
|
}
|
|
#else
|
|
if (ctx->s != -1) {
|
|
tcsetattr(ctx->s, TCSANOW, &ctx_rtu->old_tios);
|
|
close(ctx->s);
|
|
ctx->s = -1;
|
|
}
|
|
#endif
|
|
}
|
|
|
|
static int _modbus_rtu_flush(modbus_t *ctx)
|
|
{
|
|
#if defined(_WIN32)
|
|
modbus_rtu_t *ctx_rtu = ctx->backend_data;
|
|
ctx_rtu->w_ser.n_bytes = 0;
|
|
return (PurgeComm(ctx_rtu->w_ser.fd, PURGE_RXCLEAR) == FALSE);
|
|
#else
|
|
return tcflush(ctx->s, TCIOFLUSH);
|
|
#endif
|
|
}
|
|
|
|
static int _modbus_rtu_select(modbus_t *ctx, fd_set *rset,
|
|
struct timeval *tv, int length_to_read)
|
|
{
|
|
int s_rc;
|
|
#if defined(_WIN32)
|
|
s_rc = win32_ser_select(&((modbus_rtu_t *)ctx->backend_data)->w_ser,
|
|
length_to_read, tv);
|
|
if (s_rc == 0) {
|
|
errno = ETIMEDOUT;
|
|
return -1;
|
|
}
|
|
|
|
if (s_rc < 0) {
|
|
return -1;
|
|
}
|
|
#else
|
|
while ((s_rc = select(ctx->s+1, rset, NULL, NULL, tv)) == -1) {
|
|
if (errno == EINTR) {
|
|
if (ctx->debug) {
|
|
fprintf(stderr, "A non blocked signal was caught\n");
|
|
}
|
|
/* Necessary after an error */
|
|
FD_ZERO(rset);
|
|
FD_SET(ctx->s, rset);
|
|
} else {
|
|
return -1;
|
|
}
|
|
}
|
|
|
|
if (s_rc == 0) {
|
|
/* Timeout */
|
|
errno = ETIMEDOUT;
|
|
return -1;
|
|
}
|
|
#endif
|
|
|
|
return s_rc;
|
|
}
|
|
|
|
static void _modbus_rtu_free(modbus_t *ctx) {
|
|
if (ctx->backend_data) {
|
|
free(((modbus_rtu_t *)ctx->backend_data)->device);
|
|
free(ctx->backend_data);
|
|
}
|
|
|
|
free(ctx);
|
|
}
|
|
|
|
const modbus_backend_t _modbus_rtu_backend = {
|
|
_MODBUS_BACKEND_TYPE_RTU,
|
|
_MODBUS_RTU_HEADER_LENGTH,
|
|
_MODBUS_RTU_CHECKSUM_LENGTH,
|
|
MODBUS_RTU_MAX_ADU_LENGTH,
|
|
_modbus_set_slave,
|
|
_modbus_rtu_build_request_basis,
|
|
_modbus_rtu_build_response_basis,
|
|
_modbus_rtu_prepare_response_tid,
|
|
_modbus_rtu_send_msg_pre,
|
|
_modbus_rtu_send,
|
|
_modbus_rtu_receive,
|
|
_modbus_rtu_recv,
|
|
_modbus_rtu_check_integrity,
|
|
_modbus_rtu_pre_check_confirmation,
|
|
_modbus_rtu_connect,
|
|
_modbus_rtu_close,
|
|
_modbus_rtu_flush,
|
|
_modbus_rtu_select,
|
|
_modbus_rtu_free
|
|
};
|
|
|
|
modbus_t* modbus_new_rtu(const char *device,
|
|
int baud, char parity, int data_bit,
|
|
int stop_bit)
|
|
{
|
|
modbus_t *ctx;
|
|
modbus_rtu_t *ctx_rtu;
|
|
|
|
/* Check device argument */
|
|
if (device == NULL || *device == 0) {
|
|
fprintf(stderr, "The device string is empty\n");
|
|
errno = EINVAL;
|
|
return NULL;
|
|
}
|
|
|
|
/* Check baud argument */
|
|
if (baud == 0) {
|
|
fprintf(stderr, "The baud rate value must not be zero\n");
|
|
errno = EINVAL;
|
|
return NULL;
|
|
}
|
|
|
|
ctx = (modbus_t *)malloc(sizeof(modbus_t));
|
|
if (ctx == NULL) {
|
|
return NULL;
|
|
}
|
|
|
|
_modbus_init_common(ctx);
|
|
ctx->backend = &_modbus_rtu_backend;
|
|
ctx->backend_data = (modbus_rtu_t *)malloc(sizeof(modbus_rtu_t));
|
|
if (ctx->backend_data == NULL) {
|
|
modbus_free(ctx);
|
|
errno = ENOMEM;
|
|
return NULL;
|
|
}
|
|
ctx_rtu = (modbus_rtu_t *)ctx->backend_data;
|
|
|
|
/* Device name and \0 */
|
|
ctx_rtu->device = (char *)malloc((strlen(device) + 1) * sizeof(char));
|
|
if (ctx_rtu->device == NULL) {
|
|
modbus_free(ctx);
|
|
errno = ENOMEM;
|
|
return NULL;
|
|
}
|
|
strcpy(ctx_rtu->device, device);
|
|
|
|
ctx_rtu->baud = baud;
|
|
if (parity == 'N' || parity == 'E' || parity == 'O') {
|
|
ctx_rtu->parity = parity;
|
|
} else {
|
|
modbus_free(ctx);
|
|
errno = EINVAL;
|
|
return NULL;
|
|
}
|
|
ctx_rtu->data_bit = data_bit;
|
|
ctx_rtu->stop_bit = stop_bit;
|
|
|
|
#if HAVE_DECL_TIOCSRS485
|
|
/* The RS232 mode has been set by default */
|
|
ctx_rtu->serial_mode = MODBUS_RTU_RS232;
|
|
#endif
|
|
|
|
#if HAVE_DECL_TIOCM_RTS
|
|
/* The RTS use has been set by default */
|
|
ctx_rtu->rts = MODBUS_RTU_RTS_NONE;
|
|
|
|
/* Calculate estimated time in micro second to send one byte */
|
|
ctx_rtu->onebyte_time = 1000000 * (1 + data_bit + (parity == 'N' ? 0 : 1) + stop_bit) / baud;
|
|
|
|
/* The internal function is used by default to set RTS */
|
|
ctx_rtu->set_rts = _modbus_rtu_ioctl_rts;
|
|
|
|
/* The delay before and after transmission when toggling the RTS pin */
|
|
ctx_rtu->rts_delay = ctx_rtu->onebyte_time;
|
|
#endif
|
|
|
|
ctx_rtu->confirmation_to_ignore = FALSE;
|
|
|
|
return ctx;
|
|
}
|