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/*
* Copyright © 2008-2010 Stéphane Raimbault <stephane.raimbault@gmail.com>
*
* This program 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 3 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, see <http://www.gnu.org/licenses/>.
*/
#include <stdio.h>
#include <unistd.h>
#include <string.h>
#include <stdlib.h>
#include <errno.h>
#include <modbus.h>
#include "unit-test.h"
enum {
TCP,
TCP_PI,
RTU
};
int main(int argc, char*argv[])
{
int socket;
modbus_t *ctx;
modbus_mapping_t *mb_mapping;
int rc;
int i;
int use_backend;
uint8_t *query;
int header_length;
if (argc > 1) {
if (strcmp(argv[1], "tcp") == 0) {
use_backend = TCP;
} else if (strcmp(argv[1], "tcppi") == 0) {
use_backend = TCP_PI;
} else if (strcmp(argv[1], "rtu") == 0) {
use_backend = RTU;
} else {
printf("Usage:\n %s [tcp|tcppi|rtu] - Modbus server for unit testing\n\n", argv[0]);
return -1;
}
} else {
/* By default */
use_backend = TCP;
}
if (use_backend == TCP) {
ctx = modbus_new_tcp("127.0.0.1", 1502);
query = malloc(MODBUS_TCP_MAX_ADU_LENGTH);
} else if (use_backend == TCP_PI) {
ctx = modbus_new_tcp_pi("::0", "1502");
query = malloc(MODBUS_TCP_MAX_ADU_LENGTH);
} else {
ctx = modbus_new_rtu("/dev/ttyUSB0", 115200, 'N', 8, 1);
modbus_set_slave(ctx, SERVER_ID);
query = malloc(MODBUS_RTU_MAX_ADU_LENGTH);
}
header_length = modbus_get_header_length(ctx);
modbus_set_debug(ctx, TRUE);
mb_mapping = modbus_mapping_new(
UT_BITS_ADDRESS + UT_BITS_NB,
UT_INPUT_BITS_ADDRESS + UT_INPUT_BITS_NB,
UT_REGISTERS_ADDRESS + UT_REGISTERS_NB,
UT_INPUT_REGISTERS_ADDRESS + UT_INPUT_REGISTERS_NB);
if (mb_mapping == NULL) {
fprintf(stderr, "Failed to allocate the mapping: %s\n",
modbus_strerror(errno));
modbus_free(ctx);
return -1;
}
/* Examples from PI_MODBUS_300.pdf.
Only the read-only input values are assigned. */
/** INPUT STATUS **/
modbus_set_bits_from_bytes(mb_mapping->tab_input_bits,
UT_INPUT_BITS_ADDRESS, UT_INPUT_BITS_NB,
UT_INPUT_BITS_TAB);
/** INPUT REGISTERS **/
for (i=0; i < UT_INPUT_REGISTERS_NB; i++) {
mb_mapping->tab_input_registers[UT_INPUT_REGISTERS_ADDRESS+i] =
UT_INPUT_REGISTERS_TAB[i];;
}
if (use_backend == TCP) {
socket = modbus_tcp_listen(ctx, 1);
modbus_tcp_accept(ctx, &socket);
} else if (use_backend == TCP_PI) {
socket = modbus_tcp_pi_listen(ctx, 1);
modbus_tcp_pi_accept(ctx, &socket);
} else {
rc = modbus_connect(ctx);
if (rc == -1) {
fprintf(stderr, "Unable to connect %s\n", modbus_strerror(errno));
modbus_free(ctx);
return -1;
}
}
for (;;) {
do {
rc = modbus_receive(ctx, query);
/* Filtered queries return 0 */
} while (rc == 0);
if (rc == -1) {
/* Connection closed by the client or error */
break;
}
/* Read holding registers */
if (query[header_length] == 0x03) {
if (MODBUS_GET_INT16_FROM_INT8(query, header_length + 3)
== UT_REGISTERS_NB_SPECIAL) {
printf("Set an incorrect number of values\n");
MODBUS_SET_INT16_TO_INT8(query, header_length + 3,
UT_REGISTERS_NB_SPECIAL - 1);
} else if (MODBUS_GET_INT16_FROM_INT8(query, header_length + 1)
== UT_REGISTERS_ADDRESS_SPECIAL) {
printf("Reply to this special register address by an exception\n");
modbus_reply_exception(ctx, query,
MODBUS_EXCEPTION_SLAVE_OR_SERVER_BUSY);
continue;
} else if (MODBUS_GET_INT16_FROM_INT8(query, header_length + 1)
== UT_REGISTERS_ADDRESS_INVALID_TID_OR_SLAVE) {
const int RAW_REQ_LENGTH = 5;
uint8_t raw_req[] = {
(use_backend == RTU) ? INVALID_SERVER_ID : 0xFF,
0x03,
0x02, 0x00, 0x00
};
printf("Reply with an invalid TID or slave\n");
modbus_send_raw_request(ctx, raw_req, RAW_REQ_LENGTH * sizeof(uint8_t));
continue;
}
}
rc = modbus_reply(ctx, query, rc, mb_mapping);
if (rc == -1) {
break;
}
}
printf("Quit the loop: %s\n", modbus_strerror(errno));
if (use_backend == TCP) {
close(socket);
}
modbus_mapping_free(mb_mapping);
free(query);
modbus_free(ctx);
return 0;
}
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