Merge pull request #966 from demetz/patch-1

consider negative values for flow and power

src/driver_ultraheat.cc

@@ -62,7 +62,7 @@ namespace
             "The current power consumption.",
             DEFAULT_PRINT_PROPERTIES,
             Quantity::Power,
-            VifScaling::Auto,
+            VifScaling::AutoSigned,
             FieldMatcher::build()
             .set(MeasurementType::Instantaneous)
             .set(VIFRange::PowerW)
@@ -73,7 +73,7 @@ namespace
             "The current heat media volume flow.",
             DEFAULT_PRINT_PROPERTIES,
             Quantity::Flow,
-            VifScaling::Auto,
+            VifScaling::AutoSigned,
             FieldMatcher::build()
             .set(MeasurementType::Instantaneous)
             .set(VIFRange::VolumeFlow)