diff --git a/server/include/log.h b/server/include/log.h
index ecde7b582..6175f48a0 100644
--- a/server/include/log.h
+++ b/server/include/log.h
@@ -5,34 +5,44 @@
  * @file
  */
  
- #ifndef _LOG_H_
+#ifndef _LOG_H_
 #define _LOG_H_
 
+#include <libconfig.h>
+
 #ifdef __GNUC__
  #define INDENT		int __attribute__ ((__cleanup__(log_outdent), unused)) _old_indent = log_indent(1);
 #else
  #define INDENT		;
 #endif
 
-/** Global debug level used by the debug() macro.
- * It defaults to V (defined by the Makefile) and can be
- * overwritten by the 'debug' setting in the config file.
- */
-extern int _debug;
-
 /** The log level which is passed as first argument to print() */
-enum log_level {
-	DEBUG,
-	INFO,
-	WARN,
-	ERROR
-};
 
+#define DEBUG	GRY("Debug")
+#define INFO	    "" 
+#define WARN	YEL("Warn")
+#define ERROR	RED("Error")
+
+/** Change log indention  for current thread.
+ *
+ * The argument level can be negative!
+ */
 int log_indent(int levels);
 
+/** A helper function the restore the previous log indention level.
+ *
+ * This function is usually called by a __cleanup__ handler (GCC C Extension).
+ * See INDENT macro.
+ */
 void log_outdent(int *);
 
-/** Reset the wallclock of debugging outputs */
+/** Set the verbosity level of debug messages.
+ *
+ * @param lvl The new debug level.
+ */
+void log_setlevel(int lvl);
+
+/** Reset the wallclock of debug messages. */
 void log_reset();
 
 /** Logs variadic messages to stdout.
@@ -40,38 +50,40 @@ void log_reset();
  * @param lvl The log level
  * @param fmt The format string (printf alike)
  */
-void log_print(enum log_level lvl, const char *fmt, ...)
+void log_print(const char *lvl, const char *fmt, ...)
 	__attribute__ ((format(printf, 2, 3)));
 
+/** Logs variadic messages to stdout.
+ *
+ * @param lvl The log level
+ * @param fmt The format string (printf alike)
+ * @param va The variadic argument list (see stdarg.h)
+ */	
+void log_vprint(const char *lvl, const char *fmt, va_list va);
+
 /** Printf alike debug message with level. */
-#define debug(lvl, msg, ...) do if (lvl <= _debug) log_print(DEBUG, msg, ##__VA_ARGS__); while (0)
+void debug(int lvl, const char *fmt, ...)
+	__attribute__ ((format(printf, 2, 3)));
 
 /** Printf alike info message. */
-#define info(msg, ...) do log_print(INFO, msg, ##__VA_ARGS__); while (0)
+void info(const char *fmt, ...)
+	__attribute__ ((format(printf, 1, 2)));
 
 /** Printf alike warning message. */
-#define warn(msg, ...) do log_print(WARN, msg, ##__VA_ARGS__); while (0)
-
+void warn(const char *fmt, ...)
+	__attribute__ ((format(printf, 1, 2)));
+	
 /** Print error and exit. */
-#define error(msg, ...) do { \
-		log_print(ERROR, msg, ##__VA_ARGS__); \
-		die(); \
-	} while (0)
+void error(const char *fmt, ...)
+	__attribute__ ((format(printf, 1, 2)));
 
 /** Print error and strerror(errno). */
-#define serror(msg, ...) do { \
-		log_print(ERROR, msg ": %s", ##__VA_ARGS__, strerror(errno)); \
-		die(); \
-	} while (0)
+void serror(const char *fmt, ...)
+	__attribute__ ((format(printf, 1, 2)));
 
 /** Print configuration error and exit. */
-#define cerror(c, msg, ...) do { \
-		log_print(ERROR, msg " in %s:%u", ##__VA_ARGS__, \
-			(config_setting_source_file(c)) ? \
-			 config_setting_source_file(c) : "(stdio)", \
-			config_setting_source_line(c)); \
-		die(); \
-	} while (0)
+void cerror(config_setting_t *cfg, const char *fmt, ...)
+	__attribute__ ((format(printf, 2, 3)));
 
 #endif /* _LOG_H_ */
 
diff --git a/server/include/utils.h b/server/include/utils.h
index fce60c599..ed7b0c3dd 100644
--- a/server/include/utils.h
+++ b/server/include/utils.h
@@ -24,39 +24,25 @@
 #endif
 
 /* Some color escape codes for pretty log messages */
-#ifndef ENABLE_OPAL_ASYNC
- #define GRY(str)	"\e[30m" str "\e[0m" /**< Print str in gray */
- #define RED(str)	"\e[31m" str "\e[0m" /**< Print str in red */
- #define GRN(str)	"\e[32m" str "\e[0m" /**< Print str in green */
- #define YEL(str)	"\e[33m" str "\e[0m" /**< Print str in yellow */
- #define BLU(str)	"\e[34m" str "\e[0m" /**< Print str in blue */
- #define MAG(str)	"\e[35m" str "\e[0m" /**< Print str in magenta */
- #define CYN(str)	"\e[36m" str "\e[0m" /**< Print str in cyan */
- #define WHT(str)	"\e[37m" str "\e[0m" /**< Print str in white */
- #define BLD(str)	"\e[1m"  str "\e[0m" /**< Print str in bold */
+#define GRY(str)	"\e[30m" str "\e[0m" /**< Print str in gray */
+#define RED(str)	"\e[31m" str "\e[0m" /**< Print str in red */
+#define GRN(str)	"\e[32m" str "\e[0m" /**< Print str in green */
+#define YEL(str)	"\e[33m" str "\e[0m" /**< Print str in yellow */
+#define BLU(str)	"\e[34m" str "\e[0m" /**< Print str in blue */
+#define MAG(str)	"\e[35m" str "\e[0m" /**< Print str in magenta */
+#define CYN(str)	"\e[36m" str "\e[0m" /**< Print str in cyan */
+#define WHT(str)	"\e[37m" str "\e[0m" /**< Print str in white */
+#define BLD(str)	"\e[1m"  str "\e[0m" /**< Print str in bold */
 
- #define GFX(chr)	"\e(0" chr "\e(B"
- #define UP(n)		"\e[" ## n ## "A"
- #define DOWN(n)	 "\e[" ## n ## "B"
- #define RIGHT(n)	"\e[" ## n ## "C"
- #define LEFT(n)	 "\e[" ## n ## "D"
-#else
- #define GRY(str)	str
- #define RED(str)	str
- #define GRN(str)	str
- #define YEL(str)	str
- #define BLU(str)	str
- #define MAG(str)	str
- #define CYN(str)	str
- #define WHT(str)	str
- #define BLD(str)	str
-
- #define GFX(chr)	" "
- #define UP(n)		""
- #define DOWN(n)	""
- #define RIGHT(n)	""
- #define LEFT(n)	""
-#endif
+/* Alternate character set */
+#define ACS(chr)	"\e(0" chr "\e(B"
+#define ACS_VERTICAL	ACS("\x78")
+#define ACS_VERTRIGHT	ACS("\x74s")
+s
+/* UTF-8 Line drawing characters */
+#define UTF8_BOX	"\xE2\x96\x88"
+#define UTF8_VERTICAL	"\xE2\x94\x82"
+#define UTF8_VERTRIGHT	"\xE2\x94\x9C"
 
 /* CPP stringification */
 #define XSTR(x)		STR(x)
diff --git a/server/src/cfg.c b/server/src/cfg.c
index ae37cea6f..ef666a061 100644
--- a/server/src/cfg.c
+++ b/server/src/cfg.c
@@ -83,8 +83,6 @@ int config_parse_global(config_setting_t *cfg, struct settings *set)
 	config_setting_lookup_int(cfg, "debug", &set->debug);
 	config_setting_lookup_float(cfg, "stats", &set->stats);
 
-	_debug = set->debug;
-
 	set->cfg = cfg;
 
 	return 0;
diff --git a/server/src/log.c b/server/src/log.c
index 61a30abee..9a27f7a09 100644
--- a/server/src/log.c
+++ b/server/src/log.c
@@ -4,20 +4,25 @@
  * @copyright 2015, Institute for Automation of Complex Power Systems, EONERC
  */
 
- #include <stdio.h>
+#include <stdio.h>
 #include <time.h>
 
 #include "log.h"
 #include "utils.h"
 
-int _debug = V;
+/** Debug level used by the debug() macro.
+ * It defaults to V (defined by the Makefile) and can be
+ * overwritten by the 'debug' setting in the configuration file.
+ */
+static int level = V;
 
+/** A global clock used to prefix the log messages. */
 static struct timespec epoch;
 
 #ifdef __GNUC__
+/** The current log indention level (per thread!). */
 static __thread int indent = 0;
 
-/** Get thread-specific pointer to indent level */
 int log_indent(int levels)
 {
 	int old = indent;
@@ -31,41 +36,47 @@ void log_outdent(int *old)
 }
 #endif
 
+void log_setlevel(int lvl)
+{
+	level = lvl;
+	debug(10, "Switched to debug level %u", level);
+}
+
 void log_reset()
 {
 	clock_gettime(CLOCK_REALTIME, &epoch);
+	debug(10, "Debug clock resetted");
 }
 
-void log_print(enum log_level lvl, const char *fmt, ...)
+void log_print(const char *lvl, const char *fmt, ...)
+{
+	va_list ap;
+	va_start(ap, fmt);
+	log_vprint(lvl, fmt, ap);
+	va_end(ap);
+}
+
+void log_vprint(const char *lvl, const char *fmt, va_list ap)
 {
 	struct timespec ts;
 	char buf[512] = "";
 
-	va_list ap;
-
 	/* Timestamp */
 	clock_gettime(CLOCK_REALTIME, &ts);
-	strap(buf, sizeof(buf), "%8.3f ", timespec_delta(&epoch, &ts));
+	strap(buf, sizeof(buf), "%10.3f ", timespec_delta(&epoch, &ts));
 
 	/* Severity */
-	switch (lvl) {
-		case DEBUG: strap(buf, sizeof(buf), BLD("%-5s "), GRY("Debug")); break;
-		case INFO:  strap(buf, sizeof(buf), BLD("%-5s "),     "     " ); break;
-		case WARN:  strap(buf, sizeof(buf), BLD("%-5s "), YEL(" Warn")); break;
-		case ERROR: strap(buf, sizeof(buf), BLD("%-5s "), RED("Error")); break;
-	}
-
+	strap(buf, sizeof(buf), BLD("%-5s "), lvl);
+	
 	/* Indention */
 #ifdef __GNUC__
 	for (int i = 0; i < indent; i++)
-		strap(buf, sizeof(buf), GFX("\x78") " ");
-	strap(buf, sizeof(buf), GFX("\x74") " ");
+		strap(buf, sizeof(buf), ACS_VERTICAL " ");
+	strap(buf, sizeof(buf), ACS_VERTRIGHT " ");
 #endif
 
 	/* Format String */
-	va_start(ap, fmt);
 	vstrap(buf, sizeof(buf), fmt, ap);
-	va_end(ap);
 	
 	/* Output */
 #ifdef ENABLE_OPAL_ASYNC
@@ -73,3 +84,79 @@ void log_print(enum log_level lvl, const char *fmt, ...)
 #endif
 	fprintf(stderr, "\r%s\n", buf);
 }
+
+/** Printf alike debug message with level. */
+void debug(int lvl, const char *fmt, ...)
+{
+	va_list ap;
+
+	if (lvl <= level) {
+		va_start(ap, fmt);
+		log_vprint(DEBUG, fmt, ap);
+		va_end(ap);
+	}
+}
+
+/** Printf alike info message. */
+void info(const char *fmt, ...)
+{
+	va_list ap;
+
+	va_start(ap, fmt);
+	log_vprint(INFO, fmt, ap);
+	va_end(ap);
+}
+
+/** Printf alike warning message. */
+void warn(const char *fmt, ...)
+{
+	va_list ap;
+
+	va_start(ap, fmt);
+	log_vprint(WARN, fmt, ap);
+	va_end(ap);
+}
+	
+/** Print error and exit. */
+void error(const char *fmt, ...)
+{
+	va_list ap;
+
+	va_start(ap, fmt);
+	log_vprint(ERROR, fmt, ap);
+	va_end(ap);
+
+	die();
+}
+
+/** Print error and strerror(errno). */
+void serror(const char *fmt, ...)
+{
+	va_list ap;
+	char buf[1024];
+	
+	va_start(ap, fmt);
+	vsnprintf(buf, sizeof(buf), fmt, ap);
+	va_end(ap);
+	
+	log_print(ERROR, "%s: %s", buf, strerror(errno));
+	die();
+}
+
+/** Print configuration error and exit. */
+void cerror(config_setting_t *cfg, const char *fmt, ...)
+{
+	va_list ap;
+	char buf[1024];
+	
+	va_start(ap, fmt);
+	vsnprintf(buf, sizeof(buf), fmt, ap);
+	va_end(ap);
+	
+	log_print(ERROR, "%s in %s:%u", buf,
+		config_setting_source_file(cfg)
+		   ? config_setting_source_file(cfg)
+		   : "(stdio)", 
+		config_setting_source_line(cfg)); 
+	die();
+}
\ No newline at end of file
diff --git a/server/src/server.c b/server/src/server.c
index 96b1d89be..da35207e9 100644
--- a/server/src/server.c
+++ b/server/src/server.c
@@ -130,8 +130,9 @@ int main(int argc, char *argv[])
 		
 	char *configfile = (argc == 2) ? argv[1] : "opal-shmem.conf";
 
-	info("This is Simulator2Simulator Server (S2SS) %s (built on %s, %s, debug=%d)",
-		BLD(YEL(VERSION)), BLD(MAG(__DATE__)), BLD(MAG(__TIME__)), _debug);
+	log_reset();
+	info("This is Simulator2Simulator Server (S2SS) %s (built on %s, %s)",
+		BLD(YEL(VERSION)), BLD(MAG(__DATE__)), BLD(MAG(__TIME__)));
 
 	/* Check priviledges */
 	if (getuid() != 0)