diff -r e723c1dd6faa -r ff7cfce737ca tests/python/c_code@c_ext/cfile.xml
--- a/tests/python/c_code@c_ext/cfile.xml	Fri Mar 13 17:19:58 2015 +0100
+++ b/tests/python/c_code@c_ext/cfile.xml	Fri Mar 13 22:36:52 2015 +0100
@@ -14,6 +14,7 @@
 volatile char PtoC=1,CtoP=2;
 
 extern long AtomicCompareExchange(long*,long, long);
+extern char *PLCID;
 
 int Simple_C_Call(int val){
   return val+1;
@@ -34,6 +35,7 @@
     res=1;
   }
   printf("C code called by Python: toC %d fromC %d\n",toC,*fromC);
+  printf("PLCID id %s\n",PLCID);
   return res;
 }