diff --git a/server/src/gtfpga.c b/server/src/gtfpga.c
index 72daded3a..8f753bbca 100644
--- a/server/src/gtfpga.c
+++ b/server/src/gtfpga.c
@@ -63,12 +63,6 @@ int gtfpga_parse(config_setting_t *cfg, struct node *n)
 	const char *slot, *id, *err;
 	config_setting_t *cfg_slot, *cfg_id;
 
-	/* Checks */
-	if (n->combine != 1) {
-		config_setting_t *cfg_combine = config_setting_get_member(cfg, "combine");
-		cerror(cfg_combine, "The GTFPGA node type does not support combining!");
-	}
-
 	pci_filter_init(NULL, &g->filter);
 
 	cfg_slot = config_setting_get_member(cfg, "slot");
@@ -247,6 +241,9 @@ int gtfpga_read(struct node *n, struct msg *pool, int poolsize, int first, int c
 	struct gtfpga *g = n->gtfpga;
 
 	struct msg *m = &pool[first % poolsize];
+	
+	if (cnt != 1)
+		error("The GTFPGA node type does not support combining!");
 
 	uint64_t runs;
 	read(g->fd_irq, &runs, sizeof(runs));
@@ -262,8 +259,10 @@ int gtfpga_read(struct node *n, struct msg *pool, int poolsize, int first, int c
 int gtfpga_write(struct node *n, struct msg *pool, int poolsize, int first, int cnt)
 {
 	// struct gtfpga *g = n->gtfpga;
-
 	// struct msg *m = &pool[first % poolsize];
+	
+	if (cnt != 1)
+		error("The GTFPGA node type does not support combining!");
 
 	return 0;
 }
diff --git a/server/src/opal.c b/server/src/opal.c
index 76d90c463..a7e90a094 100644
--- a/server/src/opal.c
+++ b/server/src/opal.c
@@ -135,12 +135,6 @@ int opal_parse(config_setting_t *cfg, struct node *n)
 {
 	struct opal *o = alloc(sizeof(struct opal));
 
-	/* Checks */
-	if (n->combine != 1) {
-		config_setting_t *cfg_combine = config_setting_get_member(cfg, "combine");
-		cerror(cfg_combine, "The OPAL-RT node type does not support combining!");
-	}
-
 	config_setting_lookup_int(cfg, "send_id", &o->send_id);
 	config_setting_lookup_int(cfg, "recv_id", &o->recv_id);
 	config_setting_lookup_bool(cfg, "reply", &o->reply);
@@ -206,6 +200,9 @@ int opal_read(struct node *n, struct msg *pool, int poolsize, int first, int cnt
 	struct msg *m = &pool[first % poolsize];
 
 	double data[MSG_VALUES];
+	
+	if (cnt != 1)
+		error("The OPAL-RT node type does not support combining!");
 
 	/* This call unblocks when the 'Data Ready' line of a send icon is asserted. */
 	do {
@@ -267,6 +264,9 @@ int opal_write(struct node *n, struct msg *pool, int poolsize, int first, int cn
 	int state;
 	int len;
 	double data[m->length];
+	
+	if (cnt != 1)
+		error("The OPAL-RT node type does not support combining!");
 
 	state = OpalGetAsyncModelState();
 	if ((state == STATE_RESET) || (state == STATE_STOP))