--- a/svghmi/gen_index_xhtml.ysl2	Wed Dec 18 13:31:22 2019 +0100
+++ b/svghmi/gen_index_xhtml.ysl2	Fri Jan 10 13:15:07 2020 +0100
@@ -238,6 +238,8 @@
         }
         | }
         |
+        | var heartbeat_index = «$indexed_hmitree/*[@hmipath = '/HEARTBEAT']/@index»;
+        |
         | var hmitree_types = [
 
         foreach "$indexed_hmitree/*" {