Index: trunk/psModules/src/camera/pmHDUUtils.c
===================================================================
--- trunk/psModules/src/camera/pmHDUUtils.c	(revision 7492)
+++ trunk/psModules/src/camera/pmHDUUtils.c	(revision 7609)
@@ -66,4 +66,24 @@
 }
 
+// Get the highest HDU
+pmHDU *pmHDUGetHighest(const pmFPA *fpa, // The FPA
+                       const pmChip *chip, // The chip, or NULL
+                       const pmCell *cell // The cell, or NULL
+                      )
+{
+    pmHDU *hdu = NULL;          // The HDU that's at the highest level
+    if (fpa) {
+        hdu = pmHDUFromFPA(fpa);
+    }
+    if (!hdu && chip) {
+        hdu = pmHDUFromChip(chip);
+    }
+    if (!hdu && cell) {
+        hdu = pmHDUFromCell(cell);
+    }
+
+    return hdu;
+}
+
 void pmHDUPrint(FILE *fd,               // File descriptor to which to print
                 const pmHDU *hdu,       // HDU to print