From 4fa917931e1b936e97f81799b42305bf27b4b446 Mon Sep 17 00:00:00 2001
From: skarg <skarg@1e814d3a-8a88-4260-be86-c0dc25669c1e>
Date: Fri, 6 Jan 2006 13:21:18 +0000
Subject: [PATCH] Added check for datalink layer define.

---
 bacnet-stack/datalink.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/bacnet-stack/datalink.c b/bacnet-stack/datalink.c
index 77df8ba1..b62d661a 100644
--- a/bacnet-stack/datalink.c
+++ b/bacnet-stack/datalink.c
@@ -39,6 +39,12 @@
 // However, it could handle multiple data links with the
 // addition of passing a network number or datalink number
 // as part of the calls.
+#if defined(BACDL_ARCNET) || defined(BACDL_MSTP) || \
+  defined(BACDL_ETHERNET)  || defined(BACDL_BIP) 
+  /* valid! */
+#else
+  #error BACDL_ARCNET, BACDL_MSTP, BACDL_ETHERNET, or BACDL_BIP must be defined! 
+#endif
 
 /* returns number of bytes sent on success, negative on failure */
 int datalink_send_pdu(