modbus/mb_runtime.c
changeset 1909 bb883e063175
child 1912 8391c11477f4
child 2479 7f08b03a5d92
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/modbus/mb_runtime.c	Sun Mar 05 00:37:54 2017 +0000
@@ -0,0 +1,615 @@
+/* File generated by Beremiz (PlugGenerate_C method of Modbus plugin) */
+
+/*
+ * Copyright (c) 2016 Mario de Sousa (msousa@fe.up.pt)
+ *
+ * This file is part of the Modbus library for Beremiz and matiec.
+ *
+ * This Modbus library is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser 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 Lesser 
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this Modbus library.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * This code is made available on the understanding that it will not be
+ * used in safety-critical situations without a full and competent review.
+ */
+
+
+#include <stdio.h>
+#include <string.h>  /* required for memcpy() */
+#include "mb_slave_and_master.h"
+#include "MB_%(locstr)s.h"
+
+
+#define MAX_MODBUS_ERROR_CODE 11
+static const char *modbus_error_messages[MAX_MODBUS_ERROR_CODE+1] = {
+    /* 0 */ "",                             /* un-used -> no error! */
+    /* 1 */ "illegal/unsuported function",
+    /* 2 */ "illegal data address",
+    /* 3 */ "illegal data value",
+    /* 4 */ "slave device failure",
+    /* 5 */ "acknowledge -> slave intends to reply later",
+    /* 6 */ "slave device busy",
+    /* 7 */ "negative acknowledge",
+    /* 8 */ "memory parity error",
+    /* 9 */ "",                             /* undefined by Modbus */
+    /* 10*/ "gateway path unavalilable",
+    /* 11*/ "gateway target device failed to respond"
+};    
+
+
+/* Execute a modbus client transaction/request */
+static int __execute_mb_request(int request_id){
+	switch (client_requests[request_id].mb_function){
+	
+	case  1: /* read coils */
+		return read_output_bits(client_requests[request_id].slave_id,
+					client_requests[request_id].address,
+					client_requests[request_id].count,
+					client_requests[request_id].coms_buffer,
+					(int) client_requests[request_id].count,
+					client_nodes[client_requests[request_id].client_node_id].mb_nd,
+					client_requests[request_id].retries,
+					&(client_requests[request_id].error_code),
+					&(client_requests[request_id].resp_timeout),
+					&(client_requests[request_id].coms_buf_mutex));
+
+	case  2: /* read discrete inputs */
+		return read_input_bits( client_requests[request_id].slave_id,
+					client_requests[request_id].address,
+					client_requests[request_id].count,
+					client_requests[request_id].coms_buffer,
+					(int) client_requests[request_id].count,
+					client_nodes[client_requests[request_id].client_node_id].mb_nd,
+					client_requests[request_id].retries,
+					&(client_requests[request_id].error_code),
+					&(client_requests[request_id].resp_timeout),
+					&(client_requests[request_id].coms_buf_mutex));
+
+	case  3: /* read holding registers */
+		return read_output_words(client_requests[request_id].slave_id,
+					client_requests[request_id].address,
+					client_requests[request_id].count,
+					client_requests[request_id].coms_buffer,
+					(int) client_requests[request_id].count,
+					client_nodes[client_requests[request_id].client_node_id].mb_nd,
+					client_requests[request_id].retries,
+					&(client_requests[request_id].error_code),
+					&(client_requests[request_id].resp_timeout),
+					&(client_requests[request_id].coms_buf_mutex));
+	
+	case  4: /* read input registers */
+		return read_input_words(client_requests[request_id].slave_id,
+					client_requests[request_id].address,
+					client_requests[request_id].count,
+					client_requests[request_id].coms_buffer,
+					(int) client_requests[request_id].count,
+					client_nodes[client_requests[request_id].client_node_id].mb_nd,
+					client_requests[request_id].retries,
+					&(client_requests[request_id].error_code),
+					&(client_requests[request_id].resp_timeout),
+					&(client_requests[request_id].coms_buf_mutex));
+
+	case  5: /* write single coil */
+		return write_output_bit(client_requests[request_id].slave_id,
+					client_requests[request_id].address,
+					client_requests[request_id].coms_buffer[0],
+					client_nodes[client_requests[request_id].client_node_id].mb_nd,
+					client_requests[request_id].retries,
+					&(client_requests[request_id].error_code),
+					&(client_requests[request_id].resp_timeout),
+					&(client_requests[request_id].coms_buf_mutex));
+
+	case  6: /* write single register */
+		return write_output_word(client_requests[request_id].slave_id,
+					client_requests[request_id].address,
+					client_requests[request_id].coms_buffer[0],
+					client_nodes[client_requests[request_id].client_node_id].mb_nd,
+					client_requests[request_id].retries,
+					&(client_requests[request_id].error_code),
+					&(client_requests[request_id].resp_timeout),
+					&(client_requests[request_id].coms_buf_mutex));
+
+	case  7: break; /* function not yet supported */
+	case  8: break; /* function not yet supported */
+	case  9: break; /* function not yet supported */
+	case 10: break; /* function not yet supported */
+	case 11: break; /* function not yet supported */
+	case 12: break; /* function not yet supported */
+	case 13: break; /* function not yet supported */
+	case 14: break; /* function not yet supported */
+	
+	case 15: /* write multiple coils */
+		return write_output_bits(client_requests[request_id].slave_id,
+					 client_requests[request_id].address,
+					 client_requests[request_id].count,
+					 client_requests[request_id].coms_buffer,
+					 client_nodes[client_requests[request_id].client_node_id].mb_nd,
+					 client_requests[request_id].retries,
+					 &(client_requests[request_id].error_code),
+					 &(client_requests[request_id].resp_timeout),
+					 &(client_requests[request_id].coms_buf_mutex));
+
+	case 16: /* write multiple registers */
+		return write_output_words(client_requests[request_id].slave_id,
+					client_requests[request_id].address,
+					client_requests[request_id].count,
+					client_requests[request_id].coms_buffer,
+					client_nodes[client_requests[request_id].client_node_id].mb_nd,
+					client_requests[request_id].retries,
+					&(client_requests[request_id].error_code),
+					&(client_requests[request_id].resp_timeout),
+					&(client_requests[request_id].coms_buf_mutex));
+	
+	default: break;  /* should never occur, if file generation is correct */
+	}
+
+	fprintf(stderr, "Modbus plugin: Modbus function %%d not supported\n", request_id); /* should never occur, if file generation is correct */
+	return -1;
+}
+
+
+
+/* pack bits from unpacked_data to packed_data */
+static inline int __pack_bits(u16 *unpacked_data, u16 start_addr, u16 bit_count,  u8  *packed_data) {
+  u8 bit;
+  u16 byte, coils_processed;
+
+  if ((0 == bit_count) || (65535-start_addr < bit_count-1))
+    return -ERR_ILLEGAL_DATA_ADDRESS; /* ERR_ILLEGAL_DATA_ADDRESS defined in mb_util.h */
+  
+  for( byte = 0, coils_processed = 0; coils_processed < bit_count; byte++) {
+    packed_data[byte] = 0;
+    for( bit = 0x01; (bit & 0xFF) && (coils_processed < bit_count); bit <<= 1, coils_processed++ ) {
+      if(unpacked_data[start_addr + coils_processed])
+            packed_data[byte] |=  bit; /*   set bit */
+      else  packed_data[byte] &= ~bit; /* reset bit */
+    }
+  }
+  return 0;
+}
+
+
+/* unpack bits from packed_data to unpacked_data */
+static inline int __unpack_bits(u16 *unpacked_data, u16 start_addr, u16 bit_count,  u8  *packed_data) {
+  u8  temp, bit;
+  u16 byte, coils_processed;
+
+  if ((0 == bit_count) || (65535-start_addr < bit_count-1))
+    return -ERR_ILLEGAL_DATA_ADDRESS; /* ERR_ILLEGAL_DATA_ADDRESS defined in mb_util.h */
+  
+  for(byte = 0, coils_processed = 0; coils_processed < bit_count; byte++) {
+    temp = packed_data[byte] ;
+    for(bit = 0x01; (bit & 0xff) && (coils_processed < bit_count); bit <<= 1, coils_processed++) {
+      unpacked_data[start_addr + coils_processed] = (temp & bit)?1:0;
+    }
+  }
+  return 0;
+}
+
+
+static int __read_inbits   (void *mem_map, u16 start_addr, u16 bit_count, u8  *data_bytes)
+  {return   __pack_bits(((server_mem_t *)mem_map)->ro_bits, start_addr, bit_count, data_bytes);}
+static int __read_outbits  (void *mem_map, u16 start_addr, u16 bit_count, u8  *data_bytes)
+  {return   __pack_bits(((server_mem_t *)mem_map)->rw_bits, start_addr, bit_count, data_bytes);}
+static int __write_outbits (void *mem_map, u16 start_addr, u16 bit_count, u8  *data_bytes)
+  {return __unpack_bits(((server_mem_t *)mem_map)->rw_bits, start_addr, bit_count, data_bytes); }
+
+
+
+static int __read_inwords  (void *mem_map, u16 start_addr, u16 word_count, u16 *data_words) {
+  u16 count;
+  // return -ERR_ILLEGAL_FUNCTION; /* function not yet supported *//* ERR_ILLEGAL_FUNCTION defined in mb_util.h */
+  
+  if ((start_addr + word_count) > MEM_AREA_SIZE)
+    return -ERR_ILLEGAL_DATA_ADDRESS; /* ERR_ILLEGAL_DATA_ADDRESS defined in mb_util.h */
+  
+  /* use memcpy() as it is more efficient...
+  for (count = 0; count < word_count ; count++)
+    data_words[count] = ((server_mem_t *)mem_map)->ro_words[count + start_addr];
+  */
+  memcpy(/* dest */ (void *)data_words,
+         /* src  */ (void *)&(((server_mem_t *)mem_map)->ro_words[start_addr]),
+         /* size */ word_count * 2);
+  return 0;
+}
+
+
+
+static int __read_outwords (void *mem_map, u16 start_addr, u16 word_count, u16 *data_words) {
+  u16 count;
+  // return -ERR_ILLEGAL_FUNCTION; /* function not yet supported *//* ERR_ILLEGAL_FUNCTION defined in mb_util.h */
+  
+  if ((start_addr + word_count) > MEM_AREA_SIZE)
+    return -ERR_ILLEGAL_DATA_ADDRESS; /* ERR_ILLEGAL_DATA_ADDRESS defined in mb_util.h */
+  
+  /* use memcpy() as it is more efficient...
+  for (count = 0; count < word_count ; count++)
+    data_words[count] = ((server_mem_t *)mem_map)->rw_words[count + start_addr];
+  */
+  memcpy(/* dest */ (void *)data_words,
+         /* src  */ (void *)&(((server_mem_t *)mem_map)->rw_words[start_addr]),
+         /* size */ word_count * 2);
+  return 0;
+}
+
+
+
+
+static int __write_outwords(void *mem_map, u16 start_addr, u16 word_count, u16 *data_words) {
+  u16 count;
+  // return -ERR_ILLEGAL_FUNCTION; /* function not yet supported *//* ERR_ILLEGAL_FUNCTION defined in mb_util.h */
+  
+  if ((start_addr + word_count) > MEM_AREA_SIZE)
+    return -ERR_ILLEGAL_DATA_ADDRESS; /* ERR_ILLEGAL_DATA_ADDRESS defined in mb_util.h */
+
+  /* WARNING: The data returned in the data_words[] array is not guaranteed to be 16 bit aligned.
+   *           It is not therefore safe to cast it to an u16 data type.
+   *           The following code cannot be used. memcpy() is used instead.
+   */
+  /*
+  for (count = 0; count < word_count ; count++)
+    ((server_mem_t *)mem_map)->rw_words[count + start_addr] = data_words[count];
+  */
+  memcpy(/* dest */ (void *)&(((server_mem_t *)mem_map)->rw_words[start_addr]),
+         /* src  */ (void *)data_words,
+         /* size */ word_count * 2);
+  return 0;
+}
+
+
+
+
+#include <pthread.h>
+
+static void *__mb_server_thread(void *_server_node)  {
+	server_node_t *server_node = _server_node;
+	mb_slave_callback_t callbacks = { 
+			&__read_inbits,
+			&__read_outbits,
+			&__write_outbits,
+			&__read_inwords,
+			&__read_outwords,
+			&__write_outwords,
+			(void *)&(server_node->mem_area)
+			};  
+	
+	// Enable thread cancelation. Enabled is default, but set it anyway to be safe.
+	pthread_setcancelstate(PTHREAD_CANCEL_ENABLE, NULL);
+
+	// mb_slave_run() should never return!
+	mb_slave_run(server_node->mb_nd /* nd */, callbacks, server_node->slave_id);
+	fprintf(stderr, "Modbus plugin: Modbus server for node %%s died unexpectedly!\n", server_node->location); /* should never occur */
+	return NULL;
+}
+
+
+
+static void *__mb_client_thread(void *_index)  {
+	int client_node_id = (char *)_index - (char *)NULL; // Use pointer arithmetic (more portable than cast)
+	struct timespec next_cycle;
+	int period_sec  =  client_nodes[client_node_id].comm_period / 1000;          /* comm_period is in ms */
+	int period_nsec = (client_nodes[client_node_id].comm_period %%1000)*1000000; /* comm_period is in ms */
+
+	// Enable thread cancelation. Enabled is default, but set it anyway to be safe.
+	pthread_setcancelstate(PTHREAD_CANCEL_ENABLE, NULL);
+	
+	// get the current time
+	clock_gettime(CLOCK_MONOTONIC, &next_cycle);
+
+	// loop the communication with the client
+	while (1) {
+		/*
+		struct timespec cur_time;
+		clock_gettime(CLOCK_MONOTONIC, &cur_time);
+		fprintf(stderr, "Modbus client thread - new cycle (%%ld:%%ld)!\n", cur_time.tv_sec, cur_time.tv_nsec);
+		*/
+		int req;
+		for (req=0; req < NUMBER_OF_CLIENT_REQTS; req ++){
+			/*just do the requests belonging to the client */
+			if (client_requests[req].client_node_id != client_node_id)
+				continue;
+			int res_tmp = __execute_mb_request(req);
+			switch (res_tmp) {
+			  case PORT_FAILURE: {
+				if (res_tmp != client_nodes[client_node_id].prev_error)
+					fprintf(stderr, "Modbus plugin: Error connecting Modbus client %%s to remote server.\n", client_nodes[client_node_id].location);
+				client_nodes[client_node_id].prev_error = res_tmp;
+				break;
+			  }
+			  case INVALID_FRAME: {
+				if ((res_tmp != client_requests[req].prev_error) && (0 == client_nodes[client_node_id].prev_error))
+					fprintf(stderr, "Modbus plugin: Modbus client request configured at location %%s was unsuccesful. Server/slave returned an invalid/corrupted frame.\n", client_requests[req].location);
+				client_requests[req].prev_error = res_tmp;
+				break;
+			  }
+			  case TIMEOUT: {
+				if ((res_tmp != client_requests[req].prev_error) && (0 == client_nodes[client_node_id].prev_error))
+					fprintf(stderr, "Modbus plugin: Modbus client request configured at location %%s timed out waiting for reply from server.\n", client_requests[req].location);
+				client_requests[req].prev_error = res_tmp;
+				break;
+			  }
+			  case MODBUS_ERROR: {
+				if (client_requests[req].prev_error != client_requests[req].error_code) {
+					fprintf(stderr, "Modbus plugin: Modbus client request configured at location %%s was unsuccesful. Server/slave returned error code 0x%%2x", client_requests[req].location, client_requests[req].error_code);
+					if (client_requests[req].error_code <= MAX_MODBUS_ERROR_CODE ) {
+						fprintf(stderr, "(%%s)", modbus_error_messages[client_requests[req].error_code]);
+						fprintf(stderr, ".\n");
+					}
+				}
+				client_requests[req].prev_error = client_requests[req].error_code;
+				break;
+			  }
+			  default: {
+				if ((res_tmp >= 0) && (client_nodes[client_node_id].prev_error != 0)) {
+					fprintf(stderr, "Modbus plugin: Modbus client %%s has reconnected to server/slave.\n", client_nodes[client_node_id].location);
+				}
+				if ((res_tmp >= 0) && (client_requests[req]        .prev_error != 0)) {
+					fprintf(stderr, "Modbus plugin: Modbus client request configured at location %%s has succesfully resumed comunication.\n", client_requests[req].location);
+				}
+				client_nodes[client_node_id].prev_error = 0;
+				client_requests[req]        .prev_error = 0;
+				break;
+			  }
+			}
+		}
+		// Determine absolute time instant for starting the next cycle
+		// struct timespec prev_cycle;
+		// prev_cycle = next_cycle;
+		next_cycle.tv_sec  += period_sec;
+		next_cycle.tv_nsec += period_nsec;
+		if (next_cycle.tv_nsec >= 1000000000) {
+			next_cycle.tv_sec  ++;
+			next_cycle.tv_nsec -= 1000000000;
+		}
+		/* It probably does not make sense to check for overflow of timer.
+		 * Even in 32 bit systems this will take at least 68 years since the computer booted
+		 * (remember, we are using CLOCK_MONOTONIC, which should start counting from 0
+		 * every time the system boots). On 64 bit systems, it will take over 
+		 * 10^11 years to overflow.
+		 */
+		/*
+		if (next_cycle.tv_sec) < prev_cycle.tv_sec) {
+			// we will lose some precision by reading the time again, 
+			// but it is better than the alternative...
+			clock_gettime(CLOCK_MONOTONIC, &next_cycle);
+			next_cycle.tv_sec  += period_sec;
+			next_cycle.tv_nsec += period_nsec;
+			if (next_cycle.tv_nsec >= 1000000000) {
+				next_cycle.tv_sec  ++;
+				next_cycle.tv_nsec -= 1000000000;
+			}
+		}
+		*/
+		clock_nanosleep(CLOCK_MONOTONIC, TIMER_ABSTIME, &next_cycle, NULL);
+	}
+
+	// humour the compiler.
+	return NULL;
+}
+
+
+
+int __init_%(locstr)s (int argc, char **argv){
+	int index;
+
+	for (index=0; index < NUMBER_OF_CLIENT_NODES;index++)
+		client_nodes[index].mb_nd = -1;
+	for (index=0; index < NUMBER_OF_SERVER_NODES;index++)
+		// mb_nd with negative numbers indicate how far it has been initialised (or not)
+		//   -2  --> no modbus node created;  no thread  created
+		//   -1  -->    modbus node created!; no thread  created
+		//  >=0  -->    modbus node created!;    thread  created!
+		server_nodes[index].mb_nd = -2; 
+
+	/* modbus library init */
+	/* Note that TOTAL_xxxNODE_COUNT are the nodes required by _ALL_ the instances of the modbus
+	 *  extension currently in the user's project. This file (MB_xx.c) is handling only one instance,
+	 *  but must initialize the library for all instances. Only the first call to mb_slave_and_master_init()
+	 *  will result in memory being allocated. All subsequent calls (by other MB_xx,c files) will be ignored
+	 *  by the mb_slave_and_master_init() funtion, as long as they are called with the same arguments.
+	 */
+	if (mb_slave_and_master_init(TOTAL_TCPNODE_COUNT, TOTAL_RTUNODE_COUNT, TOTAL_ASCNODE_COUNT) <0) {
+		fprintf(stderr, "Modbus plugin: Error starting modbus library\n");
+		// return imediately. Do NOT goto error_exit, as we did not get to
+		//  start the modbus library!
+		return -1;
+	}
+	
+	/* init the mutex for each client request */
+	/* Must be done _before_ launching the client threads!! */
+	for (index=0; index < NUMBER_OF_CLIENT_REQTS; index ++){
+		if (pthread_mutex_init(&(client_requests[index].coms_buf_mutex), NULL)) {
+			fprintf(stderr, "Modbus plugin: Error initializing request for modbus client node %%s\n", client_nodes[client_requests[index].client_node_id].location);
+			goto error_exit;
+		}
+	}
+
+	/* init each client connection to remote modbus server, and launch thread */
+	/* NOTE: All client_nodes[].init_state are initialised to 0 in the code 
+	 *       generated by the modbus plugin 
+	 */
+	for (index=0; index < NUMBER_OF_CLIENT_NODES;index++){
+		/* establish client connection */
+		client_nodes[index].mb_nd = mb_master_connect (client_nodes[index].node_address);
+		if (client_nodes[index].mb_nd < 0){
+			fprintf(stderr, "Modbus plugin: Error creating modbus client node %%s\n", client_nodes[index].location);
+			goto error_exit;
+		}
+		client_nodes[index].init_state = 1; // we have created the node 
+		
+		/* launch a thread to handle this client node */
+		{
+			int res = 0;
+			pthread_attr_t attr;
+			res |= pthread_attr_init(&attr);
+			res |= pthread_create(&(client_nodes[index].thread_id), &attr, &__mb_client_thread, (void *)((char *)NULL + index));
+			if (res !=  0) {
+				fprintf(stderr, "Modbus plugin: Error starting modbus client thread for node %%s\n", client_nodes[index].location);
+				goto error_exit;
+			}
+		}
+		client_nodes[index].init_state = 2; // we have created the node and a thread
+	}
+
+	/* init each local server */
+	/* NOTE: All server_nodes[].init_state are initialised to 0 in the code 
+	 *       generated by the modbus plugin 
+	 */
+	for (index=0; index < NUMBER_OF_SERVER_NODES;index++){
+		/* create the modbus server */
+		server_nodes[index].mb_nd = mb_slave_new (server_nodes[index].node_address);
+		if (server_nodes[index].mb_nd < 0){
+			fprintf(stderr, "Modbus plugin: Error creating modbus server node %%s\n", server_nodes[index].location);
+			goto error_exit;
+		}
+		server_nodes[index].init_state = 1; // we have created the node
+		
+		/* launch a thread to handle this server node */
+		{
+			int res = 0;
+			pthread_attr_t attr;
+			res |= pthread_attr_init(&attr);
+			res |= pthread_create(&(server_nodes[index].thread_id), &attr, &__mb_server_thread, (void *)&(server_nodes[index]));
+			if (res !=  0) {
+				fprintf(stderr, "Modbus plugin: Error starting modbus server thread for node %%s\n", server_nodes[index].location);
+				goto error_exit;
+			}
+		}
+		server_nodes[index].init_state = 2; // we have created the node and thread
+	}
+
+	return 0;
+	
+error_exit:
+	__cleanup_%(locstr)s ();
+	return -1;
+}
+
+
+
+
+
+void __publish_%(locstr)s (){
+	int index;
+
+	for (index=0; index < NUMBER_OF_CLIENT_REQTS; index ++){
+		/*just do the output requests */
+		if (client_requests[index].req_type == req_output){
+			pthread_mutex_lock(&(client_requests[index].coms_buf_mutex));
+			// copy from plcv_buffer to coms_buffer
+			memcpy((void *)client_requests[index].coms_buffer /* destination */,
+			       (void *)client_requests[index].plcv_buffer /* source */,
+			       REQ_BUF_SIZE * sizeof(u16) /* size in bytes */);
+			pthread_mutex_unlock(&(client_requests[index].coms_buf_mutex));
+		}
+	}
+}
+
+
+
+
+
+void __retrieve_%(locstr)s (){
+	int index;
+
+	for (index=0; index < NUMBER_OF_CLIENT_REQTS; index ++){
+		/*just do the input requests */
+		if (client_requests[index].req_type == req_input){
+			pthread_mutex_lock(&(client_requests[index].coms_buf_mutex));
+			// copy from coms_buffer to plcv_buffer
+			memcpy((void *)client_requests[index].plcv_buffer /* destination */,
+			       (void *)client_requests[index].coms_buffer /* source */,
+			       REQ_BUF_SIZE * sizeof(u16) /* size in bytes */);
+			pthread_mutex_unlock(&(client_requests[index].coms_buf_mutex));
+		}
+	}
+}
+
+
+
+
+
+int __cleanup_%(locstr)s (){
+	int index, close;
+	int res = 0;
+
+	/* kill thread and close connections of each modbus client node */
+	for (index=0; index < NUMBER_OF_CLIENT_NODES; index++) {
+		close = 0;
+		if (client_nodes[index].init_state >= 2) {
+			// thread was launched, so we try to cancel it!
+			close  = pthread_cancel(client_nodes[index].thread_id);
+			close |= pthread_join  (client_nodes[index].thread_id, NULL);
+			if (close < 0)
+				fprintf(stderr, "Modbus plugin: Error closing thread for modbus client %%s\n", client_nodes[index].location);
+		}
+		res |= close;
+
+		close = 0;
+		if (client_nodes[index].init_state >= 1) {
+			// modbus client node was created, so we try to close it!
+			close = mb_master_close (client_nodes[index].mb_nd);
+			if (close < 0){
+				fprintf(stderr, "Modbus plugin: Error closing modbus client node %%s\n", client_nodes[index].location);
+				// We try to shut down as much as possible, so we do not return noW!
+			}
+			client_nodes[index].mb_nd = -1;
+		}
+		res |= close;
+		client_nodes[index].init_state = 0;
+	}
+	
+	/* kill thread and close connections of each modbus server node */
+	for (index=0; index < NUMBER_OF_SERVER_NODES; index++) {
+		close = 0;
+		if (server_nodes[index].init_state >= 2) {
+			// thread was launched, so we try to cancel it!
+			close  = pthread_cancel(server_nodes[index].thread_id);
+			close |= pthread_join  (server_nodes[index].thread_id, NULL);
+			if (close < 0)
+				fprintf(stderr, "Modbus plugin: Error closing thread for modbus server %%s\n", server_nodes[index].location);
+		}
+		res |= close;
+
+		close = 0;
+		if (server_nodes[index].init_state >= 1) {
+			// modbus server node was created, so we try to close it!
+			close = mb_slave_close (server_nodes[index].mb_nd);
+			if (close < 0) {
+				fprintf(stderr, "Modbus plugin: Error closing node for modbus server %%s (%%d)\n", server_nodes[index].location, server_nodes[index].mb_nd);
+				// We try to shut down as much as possible, so we do not return noW!
+			}
+			server_nodes[index].mb_nd = -1;
+		}
+		res |= close;
+		server_nodes[index].init_state = 0;
+	}
+
+	/* destroy the mutex of each client request */
+	for (index=0; index < NUMBER_OF_CLIENT_REQTS; index ++) {
+		if (pthread_mutex_destroy(&(client_requests[index].coms_buf_mutex))) {
+			fprintf(stderr, "Modbus plugin: Error destroying request for modbus client node %%s\n", client_nodes[client_requests[index].client_node_id].location);
+			// We try to shut down as much as possible, so we do not return noW!
+			res |= -1;
+		}
+	}
+
+	/* modbus library close */
+	//fprintf(stderr, "Shutting down modbus library...\n");
+	if (mb_slave_and_master_done()<0) {
+		fprintf(stderr, "Modbus plugin: Error shutting down modbus library\n");
+		res |= -1;
+	}
+
+	return res;
+}
+