diff --git a/go/src/v.io/x/sensorlog/internal/sbmodel/sbmodel.vdl.go b/go/src/v.io/x/sensorlog/internal/sbmodel/sbmodel.vdl.go
index 1f1bd6f..bff9f2a 100644
--- a/go/src/v.io/x/sensorlog/internal/sbmodel/sbmodel.vdl.go
+++ b/go/src/v.io/x/sensorlog/internal/sbmodel/sbmodel.vdl.go
@@ -636,9 +636,10 @@
 	VDataPointError struct{ Value string }
 	// __VDataPointReflect describes the VDataPoint union type.
 	__VDataPointReflect struct {
-		Name  string `vdl:"v.io/x/sensorlog/internal/sbmodel.VDataPoint"`
-		Type  VDataPoint
-		Union struct {
+		Name               string `vdl:"v.io/x/sensorlog/internal/sbmodel.VDataPoint"`
+		Type               VDataPoint
+		UnionTargetFactory vDataPointTargetFactory
+		Union              struct {
 			Value VDataPointValue
 			Error VDataPointError
 		}
@@ -707,6 +708,57 @@
 	return nil
 }
 
+type VDataPointTarget struct {
+	Value     *VDataPoint
+	fieldName string
+
+	vdl.TargetBase
+	vdl.FieldsTargetBase
+}
+
+func (t *VDataPointTarget) StartFields(tt *vdl.Type) (vdl.FieldsTarget, error) {
+	if ttWant := vdl.TypeOf((*VDataPoint)(nil)); !vdl.Compatible(tt, ttWant) {
+		return nil, fmt.Errorf("type %v incompatible with %v", tt, ttWant)
+	}
+
+	return t, nil
+}
+func (t *VDataPointTarget) StartField(name string) (key, field vdl.Target, _ error) {
+	t.fieldName = name
+	switch name {
+	case "Value":
+		val := float64(0)
+		return nil, &vdl.Float64Target{Value: &val}, nil
+	case "Error":
+		val := ""
+		return nil, &vdl.StringTarget{Value: &val}, nil
+	default:
+		return nil, nil, fmt.Errorf("field %s not in union v.io/x/sensorlog/internal/sbmodel.VDataPoint", name)
+	}
+}
+func (t *VDataPointTarget) FinishField(_, fieldTarget vdl.Target) error {
+	switch t.fieldName {
+	case "Value":
+		*t.Value = VDataPointValue{*(fieldTarget.(*vdl.Float64Target)).Value}
+	case "Error":
+		*t.Value = VDataPointError{*(fieldTarget.(*vdl.StringTarget)).Value}
+	}
+	return nil
+}
+func (t *VDataPointTarget) FinishFields(_ vdl.FieldsTarget) error {
+
+	return nil
+}
+
+type vDataPointTargetFactory struct{}
+
+func (t vDataPointTargetFactory) VDLMakeUnionTarget(union interface{}) (vdl.Target, error) {
+	if typedUnion, ok := union.(*VDataPoint); ok {
+		return &VDataPointTarget{Value: typedUnion}, nil
+	}
+	return nil, fmt.Errorf("got %T, want *VDataPoint", union)
+}
+
 // Create zero values for each type.
 var (
 	__VDLZeroVDeviceCfg = VDeviceCfg{}