diff --git a/bin/mbus-serial-request-data-multi-reply.c b/bin/mbus-serial-request-data-multi-reply.c
index 787a651..91a2642 100755
--- a/bin/mbus-serial-request-data-multi-reply.c
+++ b/bin/mbus-serial-request-data-multi-reply.c
@@ -8,10 +8,6 @@
 //
 //------------------------------------------------------------------------------
 
-#include <sys/types.h>
-#include <sys/stat.h>
-#include <fcntl.h>
-#include <unistd.h>
 #include <string.h>
 
 #include <stdio.h>
diff --git a/bin/mbus-serial-request-data.c b/bin/mbus-serial-request-data.c
index c65e54f..f1eaaf0 100755
--- a/bin/mbus-serial-request-data.c
+++ b/bin/mbus-serial-request-data.c
@@ -8,10 +8,6 @@
 //
 //------------------------------------------------------------------------------
 
-#include <sys/types.h>
-#include <sys/stat.h>
-#include <fcntl.h>
-#include <unistd.h>
 #include <string.h>
 
 #include <stdio.h>
diff --git a/bin/mbus-serial-scan-secondary.c b/bin/mbus-serial-scan-secondary.c
index a5b6ed2..e85355e 100755
--- a/bin/mbus-serial-scan-secondary.c
+++ b/bin/mbus-serial-scan-secondary.c
@@ -8,10 +8,6 @@
 //
 //------------------------------------------------------------------------------
 
-#include <sys/types.h>
-#include <sys/stat.h>
-#include <fcntl.h>
-#include <unistd.h>
 #include <string.h>
 
 #include <stdio.h>
@@ -90,7 +86,7 @@ main(int argc, char **argv)
         device = argv[3];   
         addr_mask = strdup("FFFFFFFFFFFFFFFF");
     }
-    else if (argc == 5 && strcmp(argv[1], "-d") == 0)
+    else if (argc == 5 && strcmp(argv[1], "-d") == 0 && strcmp(argv[2], "-b") == 0)
     {
         baudrate = atoi(argv[3]);
         device = argv[4];   
diff --git a/bin/mbus-serial-scan.c b/bin/mbus-serial-scan.c
index 2509e89..f4bae6b 100755
--- a/bin/mbus-serial-scan.c
+++ b/bin/mbus-serial-scan.c
@@ -8,10 +8,6 @@
 //
 //------------------------------------------------------------------------------
 
-#include <sys/types.h>
-#include <sys/stat.h>
-#include <fcntl.h>
-#include <unistd.h>
 #include <string.h>
 
 #include <stdio.h>
diff --git a/bin/mbus-serial-select-secondary.c b/bin/mbus-serial-select-secondary.c
index ccb16b9..628d45b 100755
--- a/bin/mbus-serial-select-secondary.c
+++ b/bin/mbus-serial-select-secondary.c
@@ -8,10 +8,6 @@
 //
 //------------------------------------------------------------------------------
 
-#include <sys/types.h>
-#include <sys/stat.h>
-#include <fcntl.h>
-#include <unistd.h>
 #include <string.h>
 
 #include <stdio.h>
diff --git a/bin/mbus-serial-switch-baudrate.c b/bin/mbus-serial-switch-baudrate.c
index 49cc969..b9186c4 100755
--- a/bin/mbus-serial-switch-baudrate.c
+++ b/bin/mbus-serial-switch-baudrate.c
@@ -11,10 +11,6 @@
 //
 //------------------------------------------------------------------------------
 
-#include <sys/types.h>
-#include <sys/stat.h>
-#include <fcntl.h>
-#include <unistd.h>
 #include <string.h>
 
 #include <stdio.h>
diff --git a/bin/mbus-tcp-raw-send.c b/bin/mbus-tcp-raw-send.c
index 526145e..8cc84f7 100644
--- a/bin/mbus-tcp-raw-send.c
+++ b/bin/mbus-tcp-raw-send.c
@@ -8,10 +8,6 @@
 //
 //------------------------------------------------------------------------------
 
-#include <sys/types.h>
-#include <sys/stat.h>
-#include <fcntl.h>
-#include <unistd.h>
 #include <string.h>
 
 #include <stdio.h>
@@ -30,8 +26,10 @@ main(int argc, char **argv)
     mbus_handle *handle = NULL;
 
     char *host, *addr_str, matching_addr[16], *file = NULL;
-    int port, address, fd, len, i, result;
-  	u_char raw_buff[4096], buff[4096], *ptr, *endptr;
+    int port, address, result;
+    FILE *fp = NULL;
+    size_t buff_len, len;
+  	u_char raw_buff[4096], buff[4096];
  
     memset((void *)&reply, 0, sizeof(mbus_frame));
     memset((void *)&reply_data, 0, sizeof(mbus_frame_data));
@@ -88,7 +86,7 @@ main(int argc, char **argv)
 
     if (mbus_connect(handle) == -1)
     {
-        fprintf(stderr, "Failed to setup connection to M-bus gateway\n");
+        fprintf(stderr, "Failed to setup connection to M-bus gateway\n%s\n", mbus_error_str());
         return 1;
     }
 
@@ -127,41 +125,35 @@ main(int argc, char **argv)
     //
     if (file != NULL)
     {
-      	if ((fd = open(file, O_RDONLY, 0)) == -1)
+        if ((fp = fopen(file, "r")) == NULL)
         {
-	    	fprintf(stderr, "%s: failed to open '%s'\n", __PRETTY_FUNCTION__, file);
+            fprintf(stderr, "%s: failed to open '%s'\n", __PRETTY_FUNCTION__, file);
             return 1;
         }
     }
     else
     {
-        fd = 0; // stdin
+        fp = stdin;
     }
 
-	memset(raw_buff, 0, sizeof(raw_buff));
-	len = read(fd, raw_buff, sizeof(raw_buff));
-	close(fd);
+    memset(raw_buff, 0, sizeof(raw_buff));
+    len = fread(raw_buff, 1, sizeof(raw_buff), fp);
 
-    ptr = 0;
-    endptr = raw_buff;
-    for (i = 0; i < sizeof(buff)-1; i++)
+    if (fp != stdin)
     {
-        ptr = endptr;
-        buff[i] = (u_char)strtol(ptr, (char **)&endptr, 16);
-        
-        // abort at non hex value 
-        if (ptr == endptr)
-            break;
+        fclose(fp);
     }
     
+    buff_len = mbus_hex2bin(buff,sizeof(buff),raw_buff,sizeof(raw_buff));
+    
     //
     // attempt to parse the input data
     //
-  	result = mbus_parse(&request, buff, i);
+    result = mbus_parse(&request, buff, buff_len);
     
-	if (result < 0)
-	{
-	    fprintf(stderr, "mbus_parse: %s\n", mbus_error_str());
+    if (result < 0)
+    {
+        fprintf(stderr, "mbus_parse: %s\n", mbus_error_str());
         return 1;
     }
     else if (result > 0)
diff --git a/bin/mbus-tcp-request-data-multi-reply.c b/bin/mbus-tcp-request-data-multi-reply.c
index c9e227e..4d932eb 100755
--- a/bin/mbus-tcp-request-data-multi-reply.c
+++ b/bin/mbus-tcp-request-data-multi-reply.c
@@ -8,10 +8,6 @@
 //
 //------------------------------------------------------------------------------
 
-#include <sys/types.h>
-#include <sys/stat.h>
-#include <fcntl.h>
-#include <unistd.h>
 #include <string.h>
 
 #include <stdio.h>
diff --git a/bin/mbus-tcp-request-data.c b/bin/mbus-tcp-request-data.c
index 2e23c5d..08fbca8 100755
--- a/bin/mbus-tcp-request-data.c
+++ b/bin/mbus-tcp-request-data.c
@@ -8,10 +8,6 @@
 //
 //------------------------------------------------------------------------------
 
-#include <sys/types.h>
-#include <sys/stat.h>
-#include <fcntl.h>
-#include <unistd.h>
 #include <string.h>
 
 #include <stdio.h>
diff --git a/bin/mbus-tcp-scan-secondary.c b/bin/mbus-tcp-scan-secondary.c
index 55b731f..761d86d 100755
--- a/bin/mbus-tcp-scan-secondary.c
+++ b/bin/mbus-tcp-scan-secondary.c
@@ -8,10 +8,6 @@
 //
 //------------------------------------------------------------------------------
 
-#include <sys/types.h>
-#include <sys/stat.h>
-#include <fcntl.h>
-#include <unistd.h>
 #include <string.h>
 
 #include <stdio.h>
diff --git a/bin/mbus-tcp-scan.c b/bin/mbus-tcp-scan.c
index 4e72bf5..44c7959 100755
--- a/bin/mbus-tcp-scan.c
+++ b/bin/mbus-tcp-scan.c
@@ -8,10 +8,6 @@
 //
 //------------------------------------------------------------------------------
 
-#include <sys/types.h>
-#include <sys/stat.h>
-#include <fcntl.h>
-#include <unistd.h>
 #include <string.h>
 
 #include <stdio.h>
diff --git a/bin/mbus-tcp-select-secondary.c b/bin/mbus-tcp-select-secondary.c
index e295b5b..2970f98 100755
--- a/bin/mbus-tcp-select-secondary.c
+++ b/bin/mbus-tcp-select-secondary.c
@@ -8,10 +8,6 @@
 //
 //------------------------------------------------------------------------------
 
-#include <sys/types.h>
-#include <sys/stat.h>
-#include <fcntl.h>
-#include <unistd.h>
 #include <string.h>
 
 #include <stdio.h>
diff --git a/mbus/mbus-protocol-aux.c b/mbus/mbus-protocol-aux.c
index f91d246..0d2645e 100755
--- a/mbus/mbus-protocol-aux.c
+++ b/mbus/mbus-protocol-aux.c
@@ -17,6 +17,7 @@
 
 #include <stdio.h>
 #include <string.h>
+#include <ctype.h>
 #include <math.h>
 
 #define MBUS_ERROR(...) fprintf (stderr, __VA_ARGS__)
@@ -1484,6 +1485,38 @@ mbus_disconnect(mbus_handle * handle)
     return handle->close(handle);
 }
 
+int
+mbus_context_set_option(mbus_handle * handle, mbus_context_option option, long value)
+{
+    if (handle == NULL)
+    {
+        MBUS_ERROR("%s: Invalid M-Bus handle to set option.\n", __PRETTY_FUNCTION__);
+        return -1;
+    }
+    
+    switch (option)
+    {
+        case MBUS_OPTION_MAX_RETRY:
+            if ((value >= 0) && (value <= 9))
+            {
+                handle->max_retry = value;
+                return 0;
+            }
+            break;
+        case MBUS_OPTION_PURGE_FIRST_FRAME:
+            if ((value == MBUS_FRAME_PURGE_NONE) ||
+                (value == MBUS_FRAME_PURGE_M2S)  ||
+                (value == MBUS_FRAME_PURGE_S2M))
+            {
+                handle->purge_first_frame = value;
+                return 0;
+            }
+            break;
+    }
+    
+    return -1; // unable to set option
+}
+
 int
 mbus_recv_frame(mbus_handle * handle, mbus_frame *frame)
 {
@@ -2152,3 +2185,50 @@ mbus_scan_2nd_address_range(mbus_handle * handle, int pos, char *addr_mask)
     free(mask);
     return 0;
 }
+
+//------------------------------------------------------------------------------
+// Convert a buffer with hex values into a buffer with binary values.
+// - invalid character stops convertion
+// - whitespaces will be ignored
+//------------------------------------------------------------------------------
+size_t
+mbus_hex2bin(u_char * dst, size_t dst_len, const u_char * src, size_t src_len)
+{
+    size_t i, result = 0;
+    unsigned long val;
+    u_char *ptr, *end, buf[3];
+    
+    if (!src || !dst)
+    {
+        return 0;
+    }
+    
+    memset(buf, 0, sizeof(buf));
+    memset(dst, 0, dst_len);
+    
+    for (i = 0; i+1 < src_len; i++)
+    {
+        // ignore whitespace
+        if (isspace(src[i]))
+            continue;
+    
+        buf[0] = src[i];
+        buf[1] = src[++i];
+        
+        end = buf;
+        ptr = end;
+        val = strtoul(ptr, (char **)&end, 16);
+        
+        // abort at non hex value 
+        if (ptr == end)
+            break;
+            
+        // abort at end of buffer
+        if (result >= dst_len)
+            break;
+            
+        dst[result++] = (u_char) val;
+    }
+    
+    return result;
+}
diff --git a/mbus/mbus-protocol-aux.h b/mbus/mbus-protocol-aux.h
index 2f18b98..c219ab2 100755
--- a/mbus/mbus-protocol-aux.h
+++ b/mbus/mbus-protocol-aux.h
@@ -24,6 +24,8 @@
  *   or
  * mbus_handle = mbus_context_tcp(host, port);
  *
+ * mbus_context_set_option(mbus_handle,option,value); // optional
+ *
  * mbus_connect(mbus_handle);
  *
  *  ...
@@ -140,6 +142,15 @@ typedef struct _mbus_record {
     char               *quantity;       /**< Quantity type (e.g. Energy) */
 } mbus_record;
 
+/**
+ * MBus handle option type
+ */
+enum _mbus_context_option {
+    MBUS_OPTION_MAX_RETRY,
+    MBUS_OPTION_PURGE_FIRST_FRAME
+};
+
+typedef enum _mbus_context_option mbus_context_option;
 
 /**
  * Event callback functions
@@ -198,6 +209,17 @@ int mbus_connect(mbus_handle * handle);
  */
 int mbus_disconnect(mbus_handle * handle);
 
+/**
+ * Set option of a M-Bus context.
+ *
+ * @param handle Initialized handle
+ * @param option option to set
+ * @param value  value to set
+ *
+ * @return Zero when successful.
+ */
+int mbus_context_set_option(mbus_handle * handle, mbus_context_option option, long value);
+
 /** 
  * Receives a frame using "unified" handle
  * 
@@ -437,6 +459,18 @@ char * mbus_frame_data_xml_normalized(mbus_frame_data *data);
  */
 int mbus_scan_2nd_address_range(mbus_handle * handle, int pos, char *addr_mask);
 
+/**
+ * Convert a buffer with hex values into a buffer with binary values.
+ *
+ * @param dst      destination buffer with binary values
+ * @param dst_len  byte count of destination buffer
+ * @param src      source buffer with hex values
+ * @param src_len  byte count of source buffer
+ *
+ * @return byte count of successful converted values
+ */
+size_t mbus_hex2bin(u_char * dst, size_t dst_len, const u_char * src, size_t src_len);
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/mbus/mbus-protocol.h b/mbus/mbus-protocol.h
index 3a9c99a..bd6192f 100755
--- a/mbus/mbus-protocol.h
+++ b/mbus/mbus-protocol.h
@@ -19,7 +19,6 @@
 #define _MBUS_PROTOCOL_H_
 
 #include <stdlib.h>
-#include <sys/types.h>
 #include <time.h>
 
 #ifdef __cplusplus
diff --git a/test/mbus_parse.c b/test/mbus_parse.c
index f55eb5e..886cc28 100644
--- a/test/mbus_parse.c
+++ b/test/mbus_parse.c
@@ -8,23 +8,17 @@
 //
 //------------------------------------------------------------------------------
 
-#include <sys/types.h>
-
 #include <err.h>
-#include <fcntl.h>
 #include <stdio.h>
-#include <termios.h>
-#include <unistd.h>
 #include <string.h>
-#include <sys/types.h>
-#include <sys/stat.h>
 
 #include <mbus/mbus-protocol.h>
 
 int
 main(int argc, char *argv[])
 {
-	int fd, len;
+    FILE *fp = NULL;
+    size_t buff_len, len;
 	u_char buf[1024];
 	mbus_frame reply;
 	mbus_frame_data frame_data;
@@ -36,16 +30,15 @@ main(int argc, char *argv[])
         return 1;
     }
 
-	if ((fd = open(argv[1], O_RDONLY, 0)) == -1)
+	if ((fp = fopen(argv[1], "r")) == NULL)
     {
-		fprintf(stderr, "%s: failed to open '%s'", argv[0], argv[1]);
+        fprintf(stderr, "%s: failed to open '%s'\n", argv[0], argv[1]);
         return 1;
     }
 
 	memset(buf, 0, sizeof(buf));
-	len = read(fd, buf, sizeof(buf));
-
-	close(fd);
+	len = fread(buf, 1, sizeof(buf), fp);
+	fclose(fp);
 
 	memset(&reply, 0, sizeof(reply));
 	memset(&frame_data, 0, sizeof(frame_data));
diff --git a/test/mbus_parse_hex.c b/test/mbus_parse_hex.c
index 75f819d..fefdd15 100644
--- a/test/mbus_parse_hex.c
+++ b/test/mbus_parse_hex.c
@@ -8,24 +8,19 @@
 //
 //------------------------------------------------------------------------------
 
-#include <sys/types.h>
-
 #include <err.h>
-#include <fcntl.h>
 #include <stdio.h>
-#include <termios.h>
-#include <unistd.h>
 #include <string.h>
-#include <sys/types.h>
-#include <sys/stat.h>
 
 #include <mbus/mbus-protocol.h>
 
 int
 main(int argc, char *argv[])
 {
-	int fd, len, i, result;
-	u_char raw_buff[4096], buff[4096], *ptr, *endptr;
+    FILE *fp = NULL;
+    size_t buff_len, len;
+	int result;
+	u_char raw_buff[4096], buff[4096];
 	mbus_frame reply;
 	mbus_frame_data frame_data;
 	char *xml_result = NULL;
@@ -35,38 +30,25 @@ main(int argc, char *argv[])
         fprintf(stderr, "usage: %s hex-file\n", argv[0]);
         return 1;
     }
-
-	if ((fd = open(argv[1], O_RDONLY, 0)) == -1)
+    
+    if ((fp = fopen(argv[1], "r")) == NULL)
     {
-		fprintf(stderr, "%s: failed to open '%s'", argv[0], argv[1]);
+        fprintf(stderr, "%s: failed to open '%s'\n", argv[0], argv[1]);
         return 1;
     }
-
-	memset(raw_buff, 0, sizeof(raw_buff));
-	len = read(fd, raw_buff, sizeof(raw_buff));
-	close(fd);
-
-    i = 0;
-    ptr    = 0;
-    endptr = raw_buff;
-    while (i < sizeof(buff)-1)
-    {
-        ptr = endptr;
-        buff[i] = (u_char)strtol(ptr, (char **)&endptr, 16);
-        
-        // abort at non hex value 
-        if (ptr == endptr)
-            break;
-           
-        i++;
-    }
+    
+    memset(raw_buff, 0, sizeof(raw_buff));
+    len = fread(raw_buff, 1, sizeof(raw_buff), fp);
+    fclose(fp);
+    
+    buff_len = mbus_hex2bin(buff,sizeof(buff),raw_buff,sizeof(raw_buff));
 
 	memset(&reply, 0, sizeof(reply));
 	memset(&frame_data, 0, sizeof(frame_data));
 	
 	//mbus_parse_set_debug(1);
 	
-	result = mbus_parse(&reply, buff, i);
+	result = mbus_parse(&reply, buff, buff_len);
 
 	if (result < 0)
 	{