/* * 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 (;;) { rc = modbus_receive(ctx, query); 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; } } 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; }