diff --git a/include/villas/msg_format.h b/include/villas/msg_format.h
index 3762825f2..cb6863d49 100644
--- a/include/villas/msg_format.h
+++ b/include/villas/msg_format.h
@@ -48,11 +48,11 @@
 #define MSG_DATA_OFFSET(msg)	((char *) (msg) + offsetof(struct msg, data))
 
 /** Initialize a message with default values */
-#define MSG_INIT(val, seq) (struct msg) {\
-	.version = MSG_VERSION,		\
-	.type = MSG_TYPE_DATA,		\
-	.endian = MSG_ENDIAN_HOST,	\
-	.values = val,	 		\
+#define MSG_INIT(len, seq) (struct msg) {\
+	.version  = MSG_VERSION,	\
+	.type     = MSG_TYPE_DATA,	\
+	.endian   = MSG_ENDIAN_HOST,	\
+	.length   = len,	 	\
 	.sequence = seq			\
 }
 
@@ -81,7 +81,7 @@ struct msg
 #endif
 	unsigned rsvd2	: 8;	/**< Reserved bits */
 	
-	uint16_t values;	/**< The number of values in msg::data[]. Endianess is specified in msg::endian. */
+	uint16_t length;	/**< The number of values in msg::data[]. Endianess is specified in msg::endian. */
 	uint32_t sequence;	/**< The sequence number is incremented by one for consecutive messages. Endianess is specified in msg::endian. */
 	
 	/** A timestamp per message. Endianess is specified in msg::endian. */
diff --git a/include/villas/nodes/fpga.h b/include/villas/nodes/fpga.h
index 1ae4eaa59..411eac847 100644
--- a/include/villas/nodes/fpga.h
+++ b/include/villas/nodes/fpga.h
@@ -33,6 +33,7 @@ struct fpga {
 	struct vfio_dev vd;		/**< VFIO device handle. */
 
 	int do_reset;			/**< Reset VILLASfpga during startup? */
+	int affinity;			/**< Affinity for MSI interrupts */
 
 	struct list ips;		/**< List of IP components on FPGA. */
 
diff --git a/include/villas/path.h b/include/villas/path.h
index fa6c9839e..a07915a6b 100644
--- a/include/villas/path.h
+++ b/include/villas/path.h
@@ -48,7 +48,7 @@ struct path
 	struct list destinations;	/**< List of all outgoing nodes */
 	struct list hooks;		/**< List of function pointers to hooks */
 
-	int values;			/**< Maximum number of values per sample for this path. */
+	int samplelen;			/**< Maximum number of values per sample for this path. */
 	int queuelen;			/**< Size of sample queue for this path. */
 	int enabled;			/**< Is this path enabled */
 	int tfd;			/**< Timer file descriptor for fixed rate sending */
diff --git a/include/villas/sample.h b/include/villas/sample.h
index 2a6c02767..e15c5a41d 100644
--- a/include/villas/sample.h
+++ b/include/villas/sample.h
@@ -17,13 +17,13 @@
 #include <sys/types.h>
 
 /** The length of a sample datastructure with \p values values in bytes. */
-#define SAMPLE_LEN(values)	(sizeof(struct sample) + SAMPLE_DATA_LEN(values))
+#define SAMPLE_LEN(len)	(sizeof(struct sample) + SAMPLE_DATA_LEN(len))
 
 /** The length of a sample data portion of a sample datastructure with \p values values in bytes. */
-#define SAMPLE_DATA_LEN(values)	((values) * sizeof(float))
+#define SAMPLE_DATA_LEN(len)	((len) * sizeof(float))
 
 /** The offset to the beginning of the data section. */
-#define SAMPLE_DATA_OFFSET(smp)	((char *) (smp) + offsetof(struct sample, values))
+#define SAMPLE_DATA_OFFSET(smp)	((char *) (smp) + offsetof(struct sample, data))
 
 /** These flags define the format which is used by sample_fscan() and sample_fprint(). */
 enum sample_flags {
@@ -49,7 +49,7 @@ struct sample {
 	union {
 		float    f;	/**< Floating point values (note msg::endian) */
 		uint32_t i;	/**< Integer values (note msg::endian) */
-	} values[];
+	} data[];
 };
 
 /** Print a sample in human readable form to a file stream.
diff --git a/lib/cfg.c b/lib/cfg.c
index a8a85b9c7..39913dc0c 100644
--- a/lib/cfg.c
+++ b/lib/cfg.c
@@ -181,8 +181,8 @@ int config_parse_path(config_setting_t *cfg,
 	if (cfg_hook)
 		config_parse_hooklist(cfg_hook, &p->hooks);
 
-	if (!config_setting_lookup_int(cfg, "values", &p->values))
-		p->values = DEFAULT_VALUES;
+	if (!config_setting_lookup_int(cfg, "values", &p->samplelen))
+		p->samplelen = DEFAULT_VALUES;
 	if (!config_setting_lookup_int(cfg, "queuelen", &p->queuelen))
 		p->queuelen = DEFAULT_QUEUELEN;
 	if (!config_setting_lookup_bool(cfg, "reverse", &reverse))
diff --git a/lib/hooks/hooks-other.c b/lib/hooks/hooks-other.c
index 06db59450..21814ef29 100644
--- a/lib/hooks/hooks-other.c
+++ b/lib/hooks/hooks-other.c
@@ -61,8 +61,8 @@ int hook_convert(struct path *p, struct hook *h, int when, struct sample *smps[]
 			for (int i = 0; i < cnt; i++) {
 				for (int j = 0; j < smps[0]->length; j++) {
 					switch (private->mode) {
-						case TO_FIXED: smps[i]->values[j].i = smps[i]->values[j].f * 1e3; break;
-						case TO_FLOAT: smps[i]->values[j].f = smps[i]->values[j].i; break;
+						case TO_FIXED: smps[i]->data[j].i = smps[i]->data[j].f * 1e3; break;
+						case TO_FLOAT: smps[i]->data[j].f = smps[i]->data[j].i; break;
 					}
 				}
 			}
diff --git a/lib/hooks/hooks-stats.c b/lib/hooks/hooks-stats.c
index 7d178e11a..06d4a4ecb 100644
--- a/lib/hooks/hooks-stats.c
+++ b/lib/hooks/hooks-stats.c
@@ -127,15 +127,15 @@ int hook_stats_send(struct path *p, struct hook *h, int when, struct sample *smp
 			else
 				length =  -1;
 			
-			smp->values[0].f = p->in->received;
-			smp->values[1].f = length;
-			smp->values[2].f = p->invalid;
-			smp->values[3].f = p->skipped;
-			smp->values[4].f = p->dropped;
-			smp->values[5].f = p->overrun;
-			smp->values[6].f =       p->hist.owd.last,
-			smp->values[7].f = 1.0 / p->hist.gap_msg.last;
-			smp->values[8].f = 1.0 / p->hist.gap_recv.last;
+			smp->data[0].f = p->in->received;
+			smp->data[1].f = length;
+			smp->data[2].f = p->invalid;
+			smp->data[3].f = p->skipped;
+			smp->data[4].f = p->dropped;
+			smp->data[5].f = p->overrun;
+			smp->data[6].f =       p->hist.owd.last,
+			smp->data[7].f = 1.0 / p->hist.gap_msg.last;
+			smp->data[8].f = 1.0 / p->hist.gap_recv.last;
 			smp->length = 9;
 			
 			node_write(private->dest, &smp, 1); /* Send single message with statistics to destination node */
diff --git a/lib/msg.c b/lib/msg.c
index 04fae60d1..704e348c2 100644
--- a/lib/msg.c
+++ b/lib/msg.c
@@ -24,12 +24,12 @@
 
 void msg_swap(struct msg *m)
 {
-	m->values   = bswap_16(m->values);
+	m->length   = bswap_16(m->length);
 	m->sequence = bswap_32(m->sequence);
 	m->ts.sec   = bswap_32(m->ts.sec);
 	m->ts.nsec  = bswap_32(m->ts.nsec);
 	
-	for (int i = 0; i < m->values; i++)
+	for (int i = 0; i < m->length; i++)
 		m->data[i].i = bswap_32(m->data[i].i);
 
 	m->endian ^= 1;
diff --git a/lib/nodes/cbuilder.c b/lib/nodes/cbuilder.c
index 765e119f4..e3abebc37 100644
--- a/lib/nodes/cbuilder.c
+++ b/lib/nodes/cbuilder.c
@@ -86,7 +86,7 @@ int cbuilder_read(struct node *n, struct sample *smps[], unsigned cnt)
 	while (cb->read >= cb->step)
 		pthread_cond_wait(&cb->cv, &cb->mtx);
 
-	smp->length = cb->model->read(&smp->values[0].f, 16);
+	smp->length = cb->model->read(&smp->data[0].f, 16);
 	smp->sequence = cb->step;
 
 	cb->read = cb->step;
@@ -103,7 +103,7 @@ int cbuilder_write(struct node *n, struct sample *smps[], unsigned cnt)
 	
 	pthread_mutex_lock(&cb->mtx);
 
-	cb->model->write(&smp->values[0].f, smp->length);
+	cb->model->write(&smp->data[0].f, smp->length);
 	cb->model->code();
 
 	cb->step++;
diff --git a/lib/nodes/ngsi.c b/lib/nodes/ngsi.c
index cfaaf872e..077b0bdc0 100644
--- a/lib/nodes/ngsi.c
+++ b/lib/nodes/ngsi.c
@@ -109,7 +109,7 @@ static json_t* ngsi_build_entity(struct ngsi *i, struct sample *smps[], unsigned
 				for (int k = 0; k < cnt; k++) {
 					json_array_append_new(values, json_pack("[ f, f, i ]",
 						time_to_double(&smps[k]->ts.origin),
-						smps[k]->values[map->index].f,
+						smps[k]->data[map->index].f,
 						smps[k]->sequence
 					));
 				}
@@ -207,7 +207,7 @@ static int ngsi_parse_entity(json_t *entity, struct ngsi *i, struct sample *smps
 				return -9;
 
 			smps[k]->ts.origin = tss;
-			smps[k]->values[map->index].f = strtof(value, &end);
+			smps[k]->data[map->index].f = strtof(value, &end);
 			if (value == end)
 				return -10;
 		}
diff --git a/lib/nodes/socket.c b/lib/nodes/socket.c
index 786a27c2a..a578b1c48 100644
--- a/lib/nodes/socket.c
+++ b/lib/nodes/socket.c
@@ -235,7 +235,7 @@ int socket_read(struct node *n, struct sample *smps[], unsigned cnt)
 	if (hdr.endian != MSG_ENDIAN_HOST)
 		msg_swap(&hdr);
 	
-	samples = bytes / MSG_LEN(hdr.values);
+	samples = bytes / MSG_LEN(hdr.length);
 	
 	if (samples > cnt) {
 		warn("Received more samples than supported. Dropping %u samples", samples - cnt);
@@ -248,7 +248,7 @@ int socket_read(struct node *n, struct sample *smps[], unsigned cnt)
 		iov[2*i+0].iov_len = MSG_LEN(0);
 		
 		iov[2*i+1].iov_base = SAMPLE_DATA_OFFSET(smps[i]);
-		iov[2*i+1].iov_len  = SAMPLE_DATA_LEN(hdr.values);
+		iov[2*i+1].iov_len  = SAMPLE_DATA_LEN(hdr.length);
 		
 		mhdr.msg_iovlen += 2;
 	}
@@ -268,14 +268,14 @@ int socket_read(struct node *n, struct sample *smps[], unsigned cnt)
 		if (ret)
 			break;
 		
-		if (m->values != hdr.values)
+		if (m->length != hdr.length)
 			break;
 
 		/* Convert message to host endianess */
 		if (m->endian != MSG_ENDIAN_HOST)
 			msg_swap(m);
 
-		s->length = m->values;
+		s->length = m->length;
 		s->sequence = m->sequence;
 		s->ts.origin = MSG_TS(m);
 	}
diff --git a/lib/nodes/vfpga.c b/lib/nodes/vfpga.c
index 4d7efa3fe..5aa9359d5 100644
--- a/lib/nodes/vfpga.c
+++ b/lib/nodes/vfpga.c
@@ -367,8 +367,7 @@ int fpga_read(struct node *n, struct sample *smps[], unsigned cnt)
 
 	size_t recvlen;
 
-	//size_t len = smp->length * sizeof(smp->values[0]);
-	size_t len = 64 * sizeof(smp->values[0]);
+	size_t len = SAMPLE_DATA_LEN(64);
 	
 	/* We dont get a sequence no from the FPGA. Lets fake it */
 	smp->sequence = n->received;
@@ -385,12 +384,12 @@ int fpga_read(struct node *n, struct sample *smps[], unsigned cnt)
 			if (ret)
 				return ret;
 
-			memcpy(smp->values, d->dma.base_virt + 0x800, recvlen);
+			memcpy(smp->data, d->dma.base_virt + 0x800, recvlen);
 
 			smp->length = recvlen / 4;
 			return 1;
 		case FPGA_DM_FIFO:
-			recvlen = fifo_read(d->ip, (char *) smp->values, len);
+			recvlen = fifo_read(d->ip, (char *) smp->data, len);
 			
 			smp->length = recvlen / 4;
 			return 1;
@@ -406,7 +405,7 @@ int fpga_write(struct node *n, struct sample *smps[], unsigned cnt)
 	struct sample *smp = smps[0];
 
 	size_t sentlen;
-	size_t len = smp->length * sizeof(smp->values[0]);
+	size_t len = smp->length * sizeof(smp->data[0]);
 
 	//intc_wait(f->intc, 5, 1);
 	
@@ -418,7 +417,7 @@ int fpga_write(struct node *n, struct sample *smps[], unsigned cnt)
 	/* Send data to RTDS */
 	switch (d->type) {
 		case FPGA_DM_DMA:
-			memcpy(d->dma.base_virt, smp->values, len);
+			memcpy(d->dma.base_virt, smp->data, len);
 
 			ret = dma_write(d->ip, d->dma.base_phys, len);
 			if (ret)
@@ -432,8 +431,8 @@ int fpga_write(struct node *n, struct sample *smps[], unsigned cnt)
 
 			return 1;
 		case FPGA_DM_FIFO:
-			sentlen = fifo_write(d->ip, (char *) smp->values, len);
-			return sentlen / sizeof(smp->values[0]);
+			sentlen = fifo_write(d->ip, (char *) smp->data, len);
+			return sentlen / sizeof(smp->data[0]);
 			break;
 	}
 	
diff --git a/lib/path.c b/lib/path.c
index 585c6b20b..e43a7d217 100644
--- a/lib/path.c
+++ b/lib/path.c
@@ -255,7 +255,7 @@ int path_prepare(struct path *p)
 		error("Failed to parse arguments for hooks of path: %s", path_name(p));
 
 	/* Initialize queue */
-	ret = pool_init_mmap(&p->pool, SAMPLE_LEN(p->values), p->queuelen);
+	ret = pool_init_mmap(&p->pool, SAMPLE_LEN(p->samplelen), p->queuelen);
 	if (ret)
 		error("Failed to allocate memory pool for path");
 	
diff --git a/lib/sample.c b/lib/sample.c
index 8206bb97e..bce894e16 100644
--- a/lib/sample.c
+++ b/lib/sample.c
@@ -26,7 +26,7 @@ int sample_print(char *buf, size_t len, struct sample *s, int flags)
 
 	if (flags & SAMPLE_VALUES) {
 		for (int i = 0; i < s->length; i++)
-			off += snprintf(buf + off, len - off, "\t%.6f", s->values[i].f);
+			off += snprintf(buf + off, len - off, "\t%.6f", s->data[i].f);
 	}
 
 	off += snprintf(buf + off, len - off, "\n");
@@ -95,7 +95,7 @@ int sample_scan(const char *line, struct sample *s, int *fl)
 	     s->length++,   ptr = end) {
 
 		/** @todo We only support floating point values at the moment */
-		s->values[s->length].f = strtod(ptr, &end);
+		s->data[s->length].f = strtod(ptr, &end);
 
 		if (end == ptr) /* there are no valid FP values anymore */
 			break;
diff --git a/src/signal.c b/src/signal.c
index ae46d3829..82e6b9e27 100644
--- a/src/signal.c
+++ b/src/signal.c
@@ -137,11 +137,11 @@ check:		if (optarg == endptr)
 		for (int i = 0; i < values; i++) {
 			int rtype = (type != TYPE_MIXED) ? type : i % 4;			
 			switch (rtype) {
-				case TYPE_RANDOM:   s->values[i].f += box_muller(0, stddev); 					break;
-				case TYPE_SINE:	    s->values[i].f = ampl *        sin(running * freq * 2 * M_PI);		break;
-				case TYPE_TRIANGLE: s->values[i].f = ampl * (fabs(fmod(running * freq, 1) - .5) - 0.25) * 4;	break;
-				case TYPE_SQUARE:   s->values[i].f = ampl * (    (fmod(running * freq, 1) < .5) ? -1 : 1);	break;
-				case TYPE_RAMP:     s->values[i].f = fmod(counter, rate / freq); /** @todo send as integer? */	break;
+				case TYPE_RANDOM:   s->data[i].f += box_muller(0, stddev); 					break;
+				case TYPE_SINE:	    s->data[i].f = ampl *        sin(running * freq * 2 * M_PI);		break;
+				case TYPE_TRIANGLE: s->data[i].f = ampl * (fabs(fmod(running * freq, 1) - .5) - 0.25) * 4;	break;
+				case TYPE_SQUARE:   s->data[i].f = ampl * (    (fmod(running * freq, 1) < .5) ? -1 : 1);	break;
+				case TYPE_RAMP:     s->data[i].f = fmod(counter, rate / freq); /** @todo send as integer? */	break;
 			}
 		}