diff --git a/CHANGELOG.md b/CHANGELOG.md
index 5b41545..f1daaf4 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -8,6 +8,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Added
 
+- manipulation SetActiveModeOfOperation for metrics
 - manipulation PhysicallyDisconnectRemovableSubsystemAfterSettingActivationStateOnOrStndBy
 - manipulation RequestIndicationOfNextCalibrationTimeRequired for devices
 - manipulation IndicateTimeOfNextCalibrationToUser for devices
diff --git a/src/t2iapi/metric/service.proto b/src/t2iapi/metric/service.proto
index f4cf64c..5943b1e 100644
--- a/src/t2iapi/metric/service.proto
+++ b/src/t2iapi/metric/service.proto
@@ -111,4 +111,13 @@ service MetricService {
    */
   rpc ConveyMetricDemoValues (BasicHandleRequest)
       returns (BasicResponse);
+
+  /*
+  The metric with the given handle shall be set to an active MODE OF OPERATION if it is representing a
+  MODE OF OPERATION. If the metric does not represent a MODE OF OPERATION, it shall return RESULT_NOT_SUPPORTED.
+
+  Hint: MODE OF OPERATION is defined in the standard 11073-10701-2022 and more details in chapter 6.2.1.
+   */
+  rpc SetActiveModeOfOperation (BasicHandleRequest)
+      returns (BasicResponse);
 }