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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>
enum {
TCP,
RTU
};
int main(int argc, char *argv[])
{
int socket;
modbus_t *ctx;
modbus_mapping_t *mb_mapping;
int rc;
int use_backend;
/* TCP */
if (argc > 1) {
if (strcmp(argv[1], "tcp") == 0) {
use_backend = TCP;
} else if (strcmp(argv[1], "rtu") == 0) {
use_backend = RTU;
} else {
printf("Usage:\n %s [tcp|rtu] - Modbus client to measure data bandwith\n\n", argv[0]);
exit(1);
}
} else {
/* By default */
use_backend = TCP;
}
if (use_backend == TCP) {
ctx = modbus_new_tcp("127.0.0.1", 1502);
socket = modbus_tcp_listen(ctx, 1);
modbus_tcp_accept(ctx, &socket);
} else {
ctx = modbus_new_rtu("/dev/ttyUSB0", 115200, 'N', 8, 1);
modbus_set_slave(ctx, 1);
modbus_connect(ctx);
}
mb_mapping = modbus_mapping_new(MODBUS_MAX_READ_BITS, 0,
MODBUS_MAX_READ_REGISTERS, 0);
if (mb_mapping == NULL) {
fprintf(stderr, "Failed to allocate the mapping: %s\n",
modbus_strerror(errno));
modbus_free(ctx);
return -1;
}
for(;;) {
uint8_t query[MODBUS_TCP_MAX_ADU_LENGTH];
rc = modbus_receive(ctx, query);
if (rc >= 0) {
modbus_reply(ctx, query, rc, mb_mapping);
} else {
/* Connection closed by the client or server */
break;
}
}
printf("Quit the loop: %s\n", modbus_strerror(errno));
modbus_mapping_free(mb_mapping);
close(socket);
modbus_free(ctx);
return 0;
}
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