diff --git a/doc/openapi/components/schemas/config/hooks/_rms.yaml b/doc/openapi/components/schemas/config/hooks/_rms.yaml
index 4a092d16f..40e60d993 100644
--- a/doc/openapi/components/schemas/config/hooks/_rms.yaml
+++ b/doc/openapi/components/schemas/config/hooks/_rms.yaml
@@ -1,3 +1,12 @@
 allOf:
 - $ref: common.yaml
 - $ref: rms.yaml
+- type: object
+  required:
+  - window_size
+  properties: 
+    window_size:
+      type: integer
+      min: 1
+      example: 1000
+      description: The number of samples in the window.
diff --git a/doc/openapi/components/schemas/config/nodes/uldaq.yaml b/doc/openapi/components/schemas/config/nodes/uldaq.yaml
index 921e240e8..3a0fc5792 100644
--- a/doc/openapi/components/schemas/config/nodes/uldaq.yaml
+++ b/doc/openapi/components/schemas/config/nodes/uldaq.yaml
@@ -8,3 +8,94 @@ allOf:
       $ref: ../format_spec.yaml
 
 - $ref: ../node.yaml
+- type: object
+  required:
+  - sample_rate
+  properties: 
+    interface_type:
+      type: string
+      enum:
+      - usb
+      - bluetooth
+      - ethernet
+      - any
+      description: The interface to which the ADC is connected. Check manual for your device.
+    device_id:
+      type: string
+      example: 10000
+      description: The used device type. If empty it is auto detected.
+    in:
+      type: object
+      description: Configuration for the ul201
+      signals:
+        type: object
+        range:
+          type: string
+          description: The range for a specific channel. See `range` for allowed values
+        input_mode:
+          type: string
+          description: The input mode for a specific channel. See `input_mode` for allowed values
+        channel:  
+          type: integer
+          example: 5
+          description: The channel input number of the device.
+        description: A list of used channels
+      sample_rate:
+        type: integer
+        min: 0
+        example: 10000
+        description: The sampling rate of the input signal.
+      range:
+        type: string
+        enum:
+        - bipolar-60
+        - bipolar-60
+        - bipolar-30
+        - bipolar-15
+        - bipolar-20
+        - bipolar-10
+        - bipolar-5
+        - bipolar-4
+        - bipolar-2.5
+        - bipolar-2
+        - bipolar-1.25
+        - bipolar-1
+        - bipolar-0.625
+        - bipolar-0.5
+        - bipolar-0.25
+        - bipolar-0.125
+        - bipolar-0.2
+        - bipolar-0.1
+        - bipolar-0.078
+        - bipolar-0.05
+        - bipolar-0.01
+        - bipolar-0.005
+        - unipolar-60
+        - unipolar-30
+        - unipolar-15
+        - unipolar-20
+        - unipolar-10
+        - unipolar-5
+        - unipolar-4
+        - unipolar-2.5
+        - unipolar-2
+        - unipolar-1.25
+        - unipolar-1
+        - unipolar-0.625
+        - unipolar-0.5
+        - unipolar-0.25
+        - unipolar-0.125
+        - unipolar-0.2
+        - unipolar-0.1
+        - unipolar-0.078
+        - unipolar-0.05
+        - unipolar-0.01
+        - unipolar-0.005
+        description: The input range. Check manual for your device.
+      input_mode:
+        type: string
+        enum:
+        - differential
+        - single-ended
+        - pseudo-differential
+        description: The sampling type. Check manual for you device
diff --git a/lib/hooks/rms.cpp b/lib/hooks/rms.cpp
index 4909419eb..09699f761 100644
--- a/lib/hooks/rms.cpp
+++ b/lib/hooks/rms.cpp
@@ -71,18 +71,24 @@ public:
 	void parse(json_t *json)
 	{
 		int ret;
+		int windowSizeIn;
 		json_error_t err;
 
 		assert(state != State::STARTED);
 
 		MultiSignalHook::parse(json);
 
-		ret = json_unpack_ex(json, &err, 0, "{ s?: i }",
-			"window_size", &windowSize
+		ret = json_unpack_ex(json, &err, 0, "{ s: i }",
+			"window_size", &windowSizeIn
 		);
 		if (ret)
 			throw ConfigError(json, err, "node-config-hook-rms");
 
+		if (windowSizeIn < 1)
+			throw ConfigError(json, "node-config-hook-rms", "Window size must be greater 0 but is set to {}", windowSizeIn);
+
+		windowSize = (unsigned)windowSizeIn;
+
 		state = State::PARSED;
 	}