diff --git a/etc/examples/nodes/ethernet.conf b/etc/examples/nodes/ethernet.conf
index 547dcd9b2..e4e4e26bf 100644
--- a/etc/examples/nodes/ethernet.conf
+++ b/etc/examples/nodes/ethernet.conf
@@ -6,10 +6,10 @@ nodes = {
 
 		layer	= "eth",
 		in = {
-			address	= "12:34:56:78:90:AB%eth0:12002"
+			address	= "12:34:56:78:90:AB%em1:12002"
 		},
 		out = {
-			address = "12:34:56:78:90:AB%eth0:12002"
+			address = "12:34:56:78:90:AB%em1:12002"
 		}	
 	},
 	unix_domain_node = {
diff --git a/etc/examples/nodes/infiniband.conf b/etc/examples/nodes/infiniband.conf
index 783f455a2..409b73e79 100644
--- a/etc/examples/nodes/infiniband.conf
+++ b/etc/examples/nodes/infiniband.conf
@@ -10,8 +10,8 @@ nodes = {
 
 		signal = "mixed",
 		values = 3,
-		frequency = 3,
-		rate = 100000,
+		frequency = 3.0,
+		rate = 100000.0,
 		limit = 100000,
 	},
 
diff --git a/etc/examples/nodes/loopback.conf b/etc/examples/nodes/loopback.conf
index cefc752e1..1ab457568 100644
--- a/etc/examples/nodes/loopback.conf
+++ b/etc/examples/nodes/loopback.conf
@@ -2,8 +2,7 @@ nodes = {
 	loopback_node = {
 		type = "loopback",			# A loopback node will receive exactly the same data which has been sent to it.
 							# The internal implementation is based on queue.
-		queuelen = 1024,				# The queue length of the internal queue which buffers the samples.
-		samplelen = 64,				# Each buffered sample can contain up to 64 values.
+		queuelen = 1024,			# The queue length of the internal queue which buffers the samples.
 		mode = "polling"			# Use busy polling for synchronization of the read and write side of the queue
 	}
 }
diff --git a/etc/examples/nodes/signal_generator.conf b/etc/examples/nodes/signal_generator.conf
index dbaeaaf17..318d7def4 100644
--- a/etc/examples/nodes/signal_generator.conf
+++ b/etc/examples/nodes/signal_generator.conf
@@ -2,9 +2,11 @@ nodes = {
 	signal_node = {
 		type = "signal",
 
-		signal = [ "sine", "pulse" ],	# One of "sine", "square", "ramp", "triangle", "random", "mixed", "counter"
-		values = 2,			# Number of values per sample
-		amplitude = [ 1.2, 0, 4 ],	# Amplitude of generated signals
+		# One of "sine", "square", "ramp", "triangle", "random", "mixed", "counter"
+		signal = [ "sine", "pulse", "square" ],
+
+		values = 3,			# Number of values per sample
+		amplitude = [ 1.2, 0.0, 4.0 ],	# Amplitude of generated signals
 		frequency = 10,			# Frequency of generated signals
 		stddev = 2,			# Standard deviation of random signals (normal distributed)
 		rate = 10.0,			# Sample rate
diff --git a/etc/labs/lab11.conf b/etc/labs/lab11.conf
index 82ee5e03e..f0df98819 100644
--- a/etc/labs/lab11.conf
+++ b/etc/labs/lab11.conf
@@ -57,7 +57,7 @@ paths = (
 
 			"rtds_gtnet2.ts.origin",
 			"rtds_gtnet2.hdr.sequence",
-			"rtds_gtnet2.data[0-6]",
+			"rtds_gtnet2.data[0-6]"
 		],
 
 		out = [
diff --git a/include/villas/config.hpp b/include/villas/config.hpp
index 3b8867ca8..c504616bf 100644
--- a/include/villas/config.hpp
+++ b/include/villas/config.hpp
@@ -84,9 +84,9 @@ public:
 
 	~Config();
 
-	json_t * load(std::FILE *f, bool resolveIncludes=true, bool resolveEnvVars=true);
+	json_t * load(std::FILE *f, bool resolveIncludes = true, bool resolveEnvVars = true);
 
-	json_t * load(const std::string &u, bool resolveIncludes=true, bool resolveEnvVars=true);
+	json_t * load(const std::string &u, bool resolveIncludes = true, bool resolveEnvVars = true);
 };
 
 } /* namespace node */
diff --git a/include/villas/node.h b/include/villas/node.h
index bea6b4528..671347d74 100644
--- a/include/villas/node.h
+++ b/include/villas/node.h
@@ -51,7 +51,7 @@
   struct rtnl_cls;
 #endif /* WITH_NETEM */
 
-#define RE_NODE_NAME "[a-z0-9_-]{3,32}"
+#define RE_NODE_NAME "[a-z0-9_-]{2,32}"
 
 /** The data structure for a node.
  *
diff --git a/include/villas/nodes/loopback_internal.hpp b/include/villas/nodes/loopback_internal.hpp
index 3c128b2be..1fb1d872f 100644
--- a/include/villas/nodes/loopback_internal.hpp
+++ b/include/villas/nodes/loopback_internal.hpp
@@ -41,7 +41,6 @@ struct sample;
  */
 struct loopback_internal {
 	int queuelen;
-	enum QueueSignalledMode mode;
 	struct queue_signalled queue;
 
 	struct vnode *source;
diff --git a/lib/config.cpp b/lib/config.cpp
index 43d114266..4fbfacbe4 100644
--- a/lib/config.cpp
+++ b/lib/config.cpp
@@ -51,7 +51,7 @@ Config::Config() :
 Config::Config(const std::string &u) :
 	Config()
 {
-	load(u);
+	root = load(u);
 }
 
 Config::~Config()
@@ -62,7 +62,7 @@ Config::~Config()
 
 json_t * Config::load(std::FILE *f, bool resolveInc, bool resolveEnvVars)
 {
-	root = decode(f);
+	json_t *root = decode(f);
 
 	if (resolveInc)
 		root = resolveIncludes(root);
@@ -87,7 +87,7 @@ json_t * Config::load(const std::string &u, bool resolveInc, bool resolveEnvVars
 		f = af->file;
 	}
 
-	root = load(f, resolveInc, resolveEnvVars);
+	json_t *root = load(f, resolveInc, resolveEnvVars);
 
 	if (af)
 		afclose(af);
@@ -182,23 +182,23 @@ json_t * Config::libconfigDecode(FILE *f)
 }
 #endif /* WITH_CONFIG */
 
-json_t * Config::walkStrings(json_t *in, str_walk_fcn_t cb)
+json_t * Config::walkStrings(json_t *root, str_walk_fcn_t cb)
 {
 	const char *key;
 	size_t index;
 	json_t *val, *new_val, *new_root;
 
-	switch (json_typeof(in)) {
+	switch (json_typeof(root)) {
 		case JSON_STRING:
-			return cb(in);
+			return cb(root);
 
 		case JSON_OBJECT:
 			new_root = json_object();
 
-			json_object_foreach(in, key, val) {
+			json_object_foreach(root, key, val) {
 				new_val = walkStrings(val, cb);
 
-				json_object_set(new_root, key, new_val);
+				json_object_set_new(new_root, key, new_val);
 			}
 
 			return new_root;
@@ -206,16 +206,16 @@ json_t * Config::walkStrings(json_t *in, str_walk_fcn_t cb)
 		case JSON_ARRAY:
 			new_root = json_array();
 
-			json_array_foreach(in, index, val) {
+			json_array_foreach(root, index, val) {
 				new_val = walkStrings(val, cb);
 
-				json_array_append(new_root, new_val);
+				json_array_append_new(new_root, new_val);
 			}
 
 			return new_root;
 
 		default:
-			return in;
+			return root;
 	};
 }
 
diff --git a/lib/hooks/CMakeLists.txt b/lib/hooks/CMakeLists.txt
index a93614196..ee5a4d78e 100644
--- a/lib/hooks/CMakeLists.txt
+++ b/lib/hooks/CMakeLists.txt
@@ -24,7 +24,7 @@ set(HOOK_SRC
     average.cpp
     cast.cpp
     decimate.cpp
-    #dp.cpp
+    dp.cpp
     drop.cpp
     dump.cpp
     ebm.cpp
diff --git a/lib/nodes/fpga.cpp b/lib/nodes/fpga.cpp
index 11d9c57b7..f11e8351f 100644
--- a/lib/nodes/fpga.cpp
+++ b/lib/nodes/fpga.cpp
@@ -112,8 +112,9 @@ int fpga_init(struct vnode *n)
 	new (&f->dma) std::shared_ptr<fpga::ip::Node>();
 	new (&f->intf) std::shared_ptr<fpga::ip::Node>();
 
-	new (&f->in.mem) std::shared_ptr<MemoryBlock>();
-	new (&f->out.mem) std::shared_ptr<MemoryBlock>();
+	// TODO: fixme
+	// new (&f->in.mem) std::shared_ptr<MemoryBlock>();
+	// new (&f->out.mem) std::shared_ptr<MemoryBlock>();
 
 	return 0;
 }
diff --git a/lib/nodes/loopback.cpp b/lib/nodes/loopback.cpp
index 94a1bb5fe..586967fe4 100644
--- a/lib/nodes/loopback.cpp
+++ b/lib/nodes/loopback.cpp
@@ -52,7 +52,7 @@ int loopback_parse(struct vnode *n, json_t *cfg)
 	json_error_t err;
 	int ret;
 
-	ret = json_unpack_ex(cfg, &err, 0, "{ s?: s }",
+	ret = json_unpack_ex(cfg, &err, 0, "{ s?: i, s?: s }",
 		"queuelen", &l->queuelen,
 		"mode", &mode_str
 	);
diff --git a/lib/nodes/loopback_internal.cpp b/lib/nodes/loopback_internal.cpp
index 69ea56265..2ba8d5610 100644
--- a/lib/nodes/loopback_internal.cpp
+++ b/lib/nodes/loopback_internal.cpp
@@ -38,7 +38,6 @@ int loopback_internal_init(struct vnode *n)
 {
 	struct loopback_internal *l = (struct loopback_internal *) n->_vd;
 
-	l->mode = QueueSignalledMode::EVENTFD;
 	l->queuelen = DEFAULT_QUEUE_LENGTH;
 
 	return 0;
@@ -46,8 +45,13 @@ int loopback_internal_init(struct vnode *n)
 
 int loopback_internal_prepare(struct vnode *n)
 {
+	int ret;
 	struct loopback_internal *l = (struct loopback_internal *) n->_vd;
 
+	ret = signal_list_copy(&n->in.signals, &l->source->in.signals);
+	if (ret)
+		return -1;
+
 	return queue_signalled_init(&l->queue, l->queuelen, memory_default, QueueSignalledMode::EVENTFD);
 }
 
@@ -84,16 +88,6 @@ int loopback_internal_write(struct vnode *n, struct sample *smps[], unsigned cnt
 	return queue_signalled_push_many(&l->queue, (void **) smps, cnt);
 }
 
-char * loopback_internal_print(struct vnode *n)
-{
-	struct loopback_internal *l = (struct loopback_internal *) n->_vd;
-	char *buf = nullptr;
-
-	strcatf(&buf, "queuelen=%d", l->queuelen);
-
-	return buf;
-}
-
 int loopback_internal_poll_fds(struct vnode *n, int fds[])
 {
 	struct loopback_internal *l = (struct loopback_internal *) n->_vd;
@@ -108,25 +102,21 @@ struct vnode * loopback_internal_create(struct vnode *orig)
 	int ret;
 	struct vnode *n;
 	struct loopback_internal *l;
-	
+
 	n = new struct vnode;
 	if (!n)
 		throw MemoryAllocationError();
 
-	l = (struct loopback_internal *) n->_vd;
-
 	ret = node_init(n, &p.node);
 	if (ret)
 		return nullptr;
 
+	l = (struct loopback_internal *) n->_vd;
+
 	l->source = orig;
 
 	asprintf(&n->name, "%s_lo%zu", node_name_short(orig), vlist_length(&orig->sources));
 
-	ret = signal_list_copy(&n->in.signals, &orig->in.signals);
-	if (ret)
-		return nullptr;
-
 	return n;
 }
 
@@ -139,7 +129,6 @@ static void register_plugin() {
 	p.node.vectorize	= 0;
 	p.node.flags		= (int) NodeFlags::PROVIDES_SIGNALS | (int) NodeFlags::INTERNAL;
 	p.node.size		= sizeof(struct loopback_internal);
-	p.node.print		= loopback_internal_print;
 	p.node.prepare		= loopback_internal_prepare;
 	p.node.init		= loopback_internal_init;
 	p.node.destroy		= loopback_internal_destroy;
diff --git a/lib/nodes/ngsi.cpp b/lib/nodes/ngsi.cpp
index e5eed207f..9073d6a85 100644
--- a/lib/nodes/ngsi.cpp
+++ b/lib/nodes/ngsi.cpp
@@ -869,7 +869,7 @@ static void register_plugin() {
 	p.node.reverse		= ngsi_reverse;
 
 	int ret = vlist_init(&p.node.instances);
-	if (ret)
+	if (!ret)
 		vlist_init_and_push(&plugins, &p);
 }
 
diff --git a/lib/nodes/signal_generator.cpp b/lib/nodes/signal_generator.cpp
index 19ec675d2..7bcdd89fd 100644
--- a/lib/nodes/signal_generator.cpp
+++ b/lib/nodes/signal_generator.cpp
@@ -259,25 +259,23 @@ int signal_generator_parse(struct vnode *n, json_t *cfg)
 					size_t i;
 					json_t *json_value;
 					json_array_foreach(a.json, i, json_value) {
-						if (!json_is_real(json_value))
-							throw ConfigError(json_value, "node-config-node-signal", "Values must gives as array of float values!");
+						if (!json_is_number(json_value))
+							throw ConfigError(json_value, "node-config-node-signal", "Values must gives as array of integer or float values!");
 
-						(*a.array)[i] = json_real_value(json_value);
+						(*a.array)[i] = json_number_value(json_value);
 					}
 
 					break;
 
+				case JSON_INTEGER:
 				case JSON_REAL:
-					if (!json_is_real(a.json))
-						throw ConfigError(a.json, "node-config-node-signal", "Values must gives as array of float values!");
-
 					for (size_t i = 0; i < s->values; i++)
-						(*a.array)[i] = json_real_value(a.json);
+						(*a.array)[i] = json_number_value(a.json);
 
 					break;
 
 				default:
-					throw ConfigError(a.json, "node-config-node-signal", "Values must given as array or scalar float value!");
+					throw ConfigError(a.json, "node-config-node-signal", "Values must given as array or scalar integer or float value!");
 			}
 		}
 		else {
@@ -398,7 +396,7 @@ int signal_generator_read(struct vnode *n, struct sample *smps[], unsigned cnt,
 	}
 
 	if (s->limit > 0 && s->counter >= (unsigned) s->limit) {
-		info("Reached limit.");
+		info("Node %s reached limit.", node_name(n));
 
 		n->state = State::STOPPING;
 
@@ -437,9 +435,13 @@ int signal_generator_poll_fds(struct vnode *n, int fds[])
 {
 	struct signal_generator *s = (struct signal_generator *) n->_vd;
 
-	fds[0] = s->task.getFD();
+	if (s->rt) {
+		fds[0] = s->task.getFD();
 
-	return 1;
+		return 1;
+	}
+	else
+		return 0;
 }
 
 static struct plugin p;
diff --git a/lib/nodes/stats.cpp b/lib/nodes/stats.cpp
index 0ad2ea0f8..61e2353e4 100644
--- a/lib/nodes/stats.cpp
+++ b/lib/nodes/stats.cpp
@@ -91,6 +91,32 @@ int stats_node_type_start(villas::node::SuperNode *sn)
 	return 0;
 }
 
+int stats_node_prepare(struct vnode *n)
+{
+	struct stats_node *s = (struct stats_node *) n->_vd;
+
+	assert(vlist_length(&n->in.signals) == 0);
+
+	/* Generate signal list */
+	for (size_t i = 0; i < vlist_length(&s->signals); i++) {
+		struct stats_node_signal *stats_sig = (struct stats_node_signal *) vlist_at(&s->signals, i);
+		struct signal *sig;
+
+		const char *metric = Stats::metrics[stats_sig->metric].name;
+		const char *type = Stats::types[stats_sig->type].name;
+
+		auto name = fmt::format("{}.{}.{}", stats_sig->node_str, metric, type);
+
+		sig = signal_create(name.c_str(),
+			Stats::metrics[stats_sig->metric].unit,
+			Stats::types[stats_sig->type].signal_type);
+
+		vlist_push(&n->in.signals, sig);
+	}
+
+	return 0;
+}
+
 int stats_node_start(struct vnode *n)
 {
 	struct stats_node *s = (struct stats_node *) n->_vd;
@@ -176,10 +202,7 @@ int stats_node_parse(struct vnode *n, json_t *cfg)
 		error("Setting 'in.signals' of node %s must be an array", node_name(n));
 
 	json_array_foreach(json_signals, i, json_signal) {
-		struct signal *sig = (struct signal *) vlist_at(&n->in.signals, i);
-		struct stats_node_signal *stats_sig;
-
-		stats_sig = new struct stats_node_signal;
+		auto *stats_sig = new struct stats_node_signal;
 		if (!stats_sig)
 			throw MemoryAllocationError();
 
@@ -187,19 +210,6 @@ int stats_node_parse(struct vnode *n, json_t *cfg)
 		if (ret)
 			error("Failed to parse statistics signal definition of node %s", node_name(n));
 
-		if (!sig->name) {
-			const char *metric = Stats::metrics[stats_sig->metric].name;
-			const char *type = Stats::types[stats_sig->type].name;
-
-			sig->name = strf("%s.%s.%s", stats_sig->node_str, metric, type);
-		}
-
-		if (!sig->unit)
-			sig->unit = strdup(Stats::metrics[stats_sig->metric].unit);
-
-		if (sig->type != Stats::types[stats_sig->type].signal_type)
-			error("Invalid type for signal %zu in node %s", i, node_name(n));
-
 		vlist_push(&s->signals, stats_sig);
 	}
 
@@ -252,13 +262,14 @@ static void register_plugin() {
 	p.type			= PluginType::NODE;
 	p.node.instances.state	= State::DESTROYED;
 	p.node.vectorize	= 1;
-	p.node.flags		= 0;
+	p.node.flags		= (int) NodeFlags::PROVIDES_SIGNALS;
 	p.node.size		= sizeof(struct stats_node);
 	p.node.type.start	= stats_node_type_start;
 	p.node.parse		= stats_node_parse;
 	p.node.init		= stats_node_init;
 	p.node.destroy		= stats_node_destroy;
 	p.node.print		= stats_node_print;
+	p.node.prepare		= stats_node_prepare;
 	p.node.start		= stats_node_start;
 	p.node.stop		= stats_node_stop;
 	p.node.read		= stats_node_read;
diff --git a/lib/nodes/test_rtt.cpp b/lib/nodes/test_rtt.cpp
index 5edb7d057..f8ab96e6b 100644
--- a/lib/nodes/test_rtt.cpp
+++ b/lib/nodes/test_rtt.cpp
@@ -228,6 +228,9 @@ int test_rtt_parse(struct vnode *n, json_t *cfg)
 				if (!c)
 					throw MemoryAllocationError();
 
+				c->filename = nullptr;
+				c->filename_formatted = nullptr;
+
 				c->rate = rates[i];
 				c->values = values[j];
 
@@ -461,7 +464,7 @@ static void register_plugin() {
 	p.node.write		= test_rtt_write;
 
 	int ret = vlist_init(&p.node.instances);
-	if (ret)
+	if (!ret)
 		vlist_init_and_push(&plugins, &p);
 }
 
diff --git a/lib/nodes/uldaq.cpp b/lib/nodes/uldaq.cpp
index b45516627..5bd63fd25 100644
--- a/lib/nodes/uldaq.cpp
+++ b/lib/nodes/uldaq.cpp
@@ -662,7 +662,7 @@ static void register_plugin() {
 	p.node.read		= uldaq_read;
 
 	int ret = vlist_init(&p.node.instances);
-	if (ret)
+	if (!ret)
 		vlist_init_and_push(&plugins, &p);
 }
 
diff --git a/lib/super_node.cpp b/lib/super_node.cpp
index 664dc6272..4da961480 100644
--- a/lib/super_node.cpp
+++ b/lib/super_node.cpp
@@ -48,7 +48,7 @@ using namespace villas::utils;
 
 SuperNode::SuperNode() :
 	state(State::INITIALIZED),
-	idleStop(false),
+	idleStop(true),
 #ifdef WITH_API
 	api(this),
 #endif
@@ -92,12 +92,12 @@ SuperNode::SuperNode() :
 
 void SuperNode::parse(const std::string &u)
 {
-	config.load(u);
+	config.root = config.load(u);
 
 	parse(config.root);
 }
 
-void SuperNode::parse(json_t *cfg)
+void SuperNode::parse(json_t *root)
 {
 	int ret;
 	const char *nme = nullptr;
@@ -107,14 +107,12 @@ void SuperNode::parse(json_t *cfg)
 	json_t *json_nodes = nullptr;
 	json_t *json_paths = nullptr;
 	json_t *json_logging = nullptr;
-	json_t *json_web = nullptr;
+	json_t *json_http = nullptr;
 
 	json_error_t err;
 
-	idleStop = true;
-
-	ret = json_unpack_ex(cfg, &err, JSON_STRICT, "{ s?: o, s?: o, s?: o, s?: o, s?: i, s?: i, s?: i, s?: s, s?: b }",
-		"http", &json_web,
+	ret = json_unpack_ex(root, &err, 0, "{ s?: o, s?: o, s?: o, s?: o, s?: i, s?: i, s?: i, s?: s, s?: b }",
+		"http", &json_http,
 		"logging", &json_logging,
 		"nodes", &json_nodes,
 		"paths", &json_paths,
@@ -125,14 +123,14 @@ void SuperNode::parse(json_t *cfg)
 		"idle_stop", &idleStop
 	);
 	if (ret)
-		throw ConfigError(cfg, err, "node-config", "Unpacking top-level config failed");
+		throw ConfigError(root, err, "node-config", "Unpacking top-level config failed");
 
 	if (nme)
 		name = nme;
 
 #ifdef WITH_WEB
-	if (json_web)
-		web.parse(json_web);
+	if (json_http)
+		web.parse(json_http);
 #endif /* WITH_WEB */
 
 	if (json_logging)
@@ -155,7 +153,7 @@ void SuperNode::parse(json_t *cfg)
 
 			ret = json_unpack_ex(json_node, &err, 0, "{ s: s }", "type", &type);
 			if (ret)
-				throw ConfigError(cfg, err, "node-config-node-type", "Failed to parse type of node '{}'", name);
+				throw ConfigError(root, err, "node-config-node-type", "Failed to parse type of node '{}'", name);
 
 			nt = node_type_lookup(type);
 			if (!nt)
@@ -359,6 +357,15 @@ void SuperNode::prepare()
 	prepareNodes();
 	preparePaths();
 
+	for (size_t i = 0; i < vlist_length(&nodes); i++) {
+		auto *n = (struct vnode *) vlist_at(&nodes, i);
+		if (vlist_length(&n->sources) == 0 &&
+		    vlist_length(&n->destinations) == 0) {
+			logger->info("Node {} is not used by any path. Disabling...");
+			n->enabled = false;
+		}
+	}
+
 	state = State::PREPARED;
 }
 
diff --git a/src/villas-test-config.cpp b/src/villas-test-config.cpp
index c85ca3efb..12101f302 100644
--- a/src/villas-test-config.cpp
+++ b/src/villas-test-config.cpp
@@ -62,8 +62,9 @@ protected:
 			<< "  CONFIG is the path to an optional configuration file" << std::endl
 			<< "  OPTIONS is one or more of the following options:" << std::endl
 			<< "    -d LVL  set debug level" << std::endl
-			<< "    -V        show version and exit" << std::endl
-			<< "    -h        show usage and exit" << std::endl << std::endl;
+			<< "    -V      show version and exit" << std::endl
+			<< "    -c      perform plausability checks on config" << std::endl
+			<< "    -h      show usage and exit" << std::endl << std::endl;
 
 		printCopyright();
 	}