modbus_t *
m_connect(char *host, char *port)
{
modbus_t *ctx;
if ((ctx = modbus_new_tcp_pi(host, port)) == NULL)
err(1, "ERROR: %s: modbus_new_tcp_pi()", __FUNCTION__);
if (f_debug > 2)
modbus_set_debug(ctx, TRUE);
if (modbus_connect(ctx) < 0) {
modbus_free(ctx);
errx(1, "ERROR: %s: modbus_connect()", __FUNCTION__);
}
return ctx;
}
static int libmodbus_new_tcp_pi(lua_State *L)
{
const char *host = luaL_checkstring(L, 1);
const char *service = luaL_checkstring(L, 2);
// Do we really need any of this? no callbacks in libmodbus?
ctx_t *ctx = (ctx_t *) lua_newuserdata(L, sizeof(ctx_t));
ctx->modbus = modbus_new_tcp_pi(host, service);
ctx->max_len = MODBUS_TCP_MAX_ADU_LENGTH;
if (ctx->modbus == NULL) {
return luaL_error(L, modbus_strerror(errno));
}
ctx->L = L;
luaL_getmetatable(L, MODBUS_META_CTX);
// Can I put more functions in for tcp here? maybe?
lua_setmetatable(L, -2);
return 1;
}
bool mbtcp_init_handle(mbtcp_handle_s **ptr_handle, char *ip, char *port)
{
BEGIN(enable_syslog);
// create a mbtcp context
modbus_t *ctx = modbus_new_tcp_pi(ip, port);
if (ctx == NULL)
{
ERR(enable_syslog, "Unable to allocate mbtcp context");
return false; // fail to allocate context
}
// set tcp connection timeout
modbus_set_response_timeout(ctx, 0, tcp_conn_timeout_usec);
// @add context to mbtcp hashtable
mbtcp_handle_s *handle;
handle = (mbtcp_handle_s*)malloc(sizeof(mbtcp_handle_s));
// let alignment bytes being set to zero-value!!
memset(handle, 0, sizeof(mbtcp_handle_s));
handle->connected = false;
strcpy(handle->key.ip, ip);
strcpy(handle->key.port, port);
handle->ctx = ctx;
HASH_ADD(hh, mbtcp_htable, key, sizeof(mbtcp_key_s), handle);
LOG(enable_syslog, "Add %s:%s to mbtcp hashtable", handle->key.ip, mbtcp_htable->key.port);
// call by reference to `mbtcp handle address`
*ptr_handle = handle;
// @connect to server
char * reason = NULL;
mbtcp_do_connect(handle, &reason);
return true;
}
int main(int argc, char*argv[])
{
int s = -1;
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;
}
/* Unit tests of modbus_mapping_new (tests would not be sufficient if two
nb_* were identical) */
if (mb_mapping->nb_bits != UT_BITS_ADDRESS + UT_BITS_NB) {
printf("Invalid nb bits (%d != %d)\n", UT_BITS_ADDRESS + UT_BITS_NB, mb_mapping->nb_bits);
modbus_free(ctx);
return -1;
}
if (mb_mapping->nb_input_bits != UT_INPUT_BITS_ADDRESS + UT_INPUT_BITS_NB) {
printf("Invalid nb input bits: %d\n", UT_INPUT_BITS_ADDRESS + UT_INPUT_BITS_NB);
modbus_free(ctx);
return -1;
}
if (mb_mapping->nb_registers != UT_REGISTERS_ADDRESS + UT_REGISTERS_NB) {
printf("Invalid nb registers: %d\n", UT_REGISTERS_ADDRESS + UT_REGISTERS_NB);
modbus_free(ctx);
return -1;
}
if (mb_mapping->nb_input_registers != UT_INPUT_REGISTERS_ADDRESS + UT_INPUT_REGISTERS_NB) {
printf("Invalid nb input registers: %d\n", UT_INPUT_REGISTERS_ADDRESS + UT_INPUT_REGISTERS_NB);
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) {
s = modbus_tcp_listen(ctx, 1);
modbus_tcp_accept(ctx, &s);
} else if (use_backend == TCP_PI) {
s = modbus_tcp_pi_listen(ctx, 1);
modbus_tcp_pi_accept(ctx, &s);
} 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);
/* The connection is not closed on errors which require on reply such as
bad CRC in RTU. */
if (rc == -1 && errno != EMBBADCRC) {
/* Quit */
break;
}
/* Special server behavior to test client */
if (query[header_length] == 0x03) {
/* Read holding registers */
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;
} else if (MODBUS_GET_INT16_FROM_INT8(query, header_length + 1)
== UT_REGISTERS_ADDRESS_SLEEP_500_MS) {
printf("Sleep 0.5 s before replying\n");
usleep(500000);
} else if (MODBUS_GET_INT16_FROM_INT8(query, header_length + 1)
== UT_REGISTERS_ADDRESS_BYTE_SLEEP_5_MS) {
/* Test low level only available in TCP mode */
/* Catch the reply and send reply byte a byte */
uint8_t req[] = "\x00\x1C\x00\x00\x00\x05\xFF\x03\x02\x00\x00";
int req_length = 11;
int w_s = modbus_get_socket(ctx);
/* Copy TID */
req[1] = query[1];
for (i=0; i < req_length; i++) {
printf("(%.2X)", req[i]);
usleep(5000);
send(w_s, (const char*)(req + i), 1, MSG_NOSIGNAL);
}
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) {
if (s != -1) {
close(s);
}
}
modbus_mapping_free(mb_mapping);
free(query);
/* For RTU */
modbus_close(ctx);
modbus_free(ctx);
return 0;
}
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) {
printf("Modbus TCP server for unit testing.\n");
ctx = modbus_new_tcp("127.0.0.1", 1502);
query = (uint8_t *)malloc(MODBUS_TCP_MAX_ADU_LENGTH);
} else if (use_backend == TCP_PI) {
ctx = modbus_new_tcp_pi("::0", "1502");
query = (uint8_t *)malloc(MODBUS_TCP_MAX_ADU_LENGTH);
} else {
printf("Modbus RTU server for unit testing.\n");
ctx = modbus_new_rtu("/dev/ttyUSB0", 115200, 'N', 8, 1);
modbus_set_slave(ctx, SERVER_ID);
query = (uint8_t *)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) {
printf("Connection closed by the client or error.\n");
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;
}