Index: mttroot/mtt/bin/trans/m/mtt_component_eqn.m
==================================================================
--- mttroot/mtt/bin/trans/m/mtt_component_eqn.m
+++ mttroot/mtt/bin/trans/m/mtt_component_eqn.m
@@ -1,6 +1,7 @@
-function [known] = mtt_component_eqn (fullname, port, causality, known)
+function [known] = mtt_component_eqn (fullname, port, causality, \
+				      known, Cbg)
 
   ## function [known] = mtt_component_eqn (fullname, port, causality, known)
   ##
   ## Recursively finds the equations giving the signal of specified
   ## causality on the specified port of component named "name" within
@@ -34,20 +35,12 @@
   eqn="## No equation -- something wrong"; # Default
 
   if length(known)<2		# Invalid
     known = "  ";
   endif
-  
-  ## File containing data structure
-  cbg_file = sprintf("%s_cbg",Name);
-
-  if (exist(cbg_file)==0)
-    error(sprintf("mtt_component_eqn: subystem \"%s\" does not exist", Name));
-  endif
-  
-  ## Subsystem data structure
-  cbg = eval(sprintf("%s;", cbg_file));
+
+  cbg = mtt_cbg(Name);		# Structure for this subsystem
 
   if struct_contains (cbg, "ports")
     ## Combine ports with the other subsystems
     for [component_structure, component] = cbg.ports
       eval(sprintf("cbg.subsystems.%s=cbg.ports.%s;",component,component));
@@ -68,11 +61,12 @@
     else			# Get name and find equation
       name = deblank(cbg.portlist(port,:));
       if DEBUG
 	disp("----> lower-level system")
       endif
-      known = mtt_component_eqn (mtt_fullname(Name,name), 1, causality, known);
+      known = mtt_component_eqn (mtt_fullname(Name,name), 1, \
+				 causality, known, cbg);
       return
     endif
   endif
   
 
@@ -176,32 +170,25 @@
       endif
     endfor
 
     ## File containing data structure
     NAME = mtt_subname(Name);
-    Cbg_file = sprintf("%s_cbg",NAME);
-
-    if (exist(Cbg_file)==0)
-      error(sprintf("mtt_component_eqn: subsystem %s does not exist", NAME));
-    endif
-    
-    ## System data structure
-    Cbg = eval(sprintf("%s;", Cbg_file));
-    
+    CBG = mtt_cbg(NAME);
     
     ## And to which component (at higher level) is it connected?
     [new_Name,new_name] = mtt_subname(Name);
-    port_bond = eval(sprintf("Cbg.subsystems.%s.connections(%i);", new_name, port_index));
-    [in_name, in_port, in_bond] = mtt_other_end (new_name,port_bond,Cbg);
+    port_bond = eval(sprintf("CBG.subsystems.%s.connections(%i);", new_name, port_index));
+    [in_name, in_port, in_bond] = mtt_other_end (new_name,port_bond,CBG);
 
     ## Find its equation
     if DEBUG
       disp("----> higher level system")
     endif
     
 
-    known = mtt_component_eqn (mtt_fullname(new_Name,in_name), in_port, causality, known);
+    known = mtt_component_eqn (mtt_fullname(new_Name,in_name), \
+			       in_port, causality, known, cbg);
 
     LHS = Source_seqn ("external",Name);
     RHS = varname(NAME, abs(in_bond), i_cause);
     eqn = sprintf("%s%s%s := %s;", LHS, SD, name, RHS);
 
@@ -224,19 +211,12 @@
     else			# Compound component
       new_NAME = Name;
       new_Name = mtt_fullname(Name,name);
       new_name = "";
       
-      ## File containing data structure
-      Cbg_file = sprintf("%s_cbg",new_Name);
-
-      if (exist(Cbg_file)==0)
-	error(sprintf("mtt_component_eqn: subsystem %s does not exist", new_Name));
-      endif
-      
-      ## System data structure
-      Cbg = eval(sprintf("%s;", Cbg_file));
+      ## Get relevant data structure
+      Cbg = mtt_cbg(new_Name);
       port_name = Cbg.portlist(port,:);
 
       LHS = varname(Name, outsig(1,1), outsig(1,2));
       RHS = Sensor_seqn ("external",new_Name);
       eqn = sprintf("%s := %s%s%s;", LHS, RHS, SD, port_name);
@@ -244,11 +224,11 @@
       if DEBUG
 	disp("----> same-level subsystem")
       endif
 
       [known] = mtt_component_eqn \
-   	  (mtt_fullname(new_Name,new_name), port, causality, known);
+   	  (mtt_fullname(new_Name,new_name), port, causality, known, cbg);
       
     endif
   endif
 
   comment = \
@@ -277,11 +257,12 @@
 	disp("----> same-level component")
       endif
       
 
       [known] = mtt_component_eqn \
-    	  (mtt_fullname(Name,other_name), other_port, other_causality, known);
+    	  (mtt_fullname(Name,other_name), other_port, other_causality, \
+	   known, cbg);
     endfor
   endif
 
   ## Write this signal
   ##comment_2 = sprintf("Connected to:%s", in_component_list);