Index: trunk/psModules/src/camera/pmReadoutStack.c
===================================================================
--- trunk/psModules/src/camera/pmReadoutStack.c	(revision 21363)
+++ trunk/psModules/src/camera/pmReadoutStack.c	(revision 24794)
@@ -252,4 +252,7 @@
             continue;
         }
+        if (!readout->process) {
+            continue;
+        }
         if (!readout->image) {
             psError(PS_ERR_UNEXPECTED_NULL, true, "Input readout %ld has NULL image.\n", i);