put all app->cs properties into error state initially

this will be cleared once the initial value has been received

include/DoocsProcessArray.h

@@ -40,6 +40,11 @@ namespace ChimeraTK {
           << ". Try selecting a different DOOCS type in the mappng XML file, e.g. a D_spectrum!";
         throw ChimeraTK::logic_error(s.str());
       }
+
+      // put variable into error state, until a valid value has been received
+      if(!_processArray->isWriteable()) {
+        this->d_error(stale_data);
+      }
     }
 
     /**

include/DoocsProcessScalar.h

@@ -123,6 +123,11 @@ namespace ChimeraTK {
         updater.addVariable(ChimeraTK::ScalarRegisterAccessor<T>(processScalar), eqFct,
             std::bind(&DoocsProcessScalar<T, DOOCS_T>::updateDoocsBuffer, this, processScalar->getId()));
         _consistencyGroup.add(processScalar);
+
+        // put variable into error state, until a valid value has been received
+        if(!_processScalar->isWriteable()) {
+          this->d_error(stale_data);
+        }
       }
     }
 
@@ -133,6 +138,11 @@ namespace ChimeraTK {
         updater.addVariable(ChimeraTK::ScalarRegisterAccessor<T>(processScalar), eqFct,
             std::bind(&DoocsProcessScalar<T, DOOCS_T>::updateDoocsBuffer, this, processScalar->getId()));
         _consistencyGroup.add(processScalar);
+
+        // put variable into error state, until a valid value has been received
+        if(!_processScalar->isWriteable()) {
+          this->d_error(stale_data);
+        }
       }
     }