diff --git a/src/lib.rs b/src/lib.rs
index 5a64d29..6875422 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -28,19 +28,37 @@ topics! {
 topics! {
     list = TOPICS_OUT_LIST;
     direction = TopicDirection::ToClient;
-    | TopicTy                   | MessageTy     | Path              | Cfg                           |
-    | -------                   | ---------     | ----              | ---                           |
-    | ImpedanceTopic            | Impedance     | "imp/data"        |                               |
+    | TopicTy                   | MessageTy       | Path              | Cfg                           |
+    | -------                   | ---------       | ----              | ---                           |
+    | ImpedanceOutputTopic      | ImpedanceOutput | "imp/data"        |                               |
 }
 
 #[derive(Serialize, Deserialize, Schema, Debug, PartialEq)]
-pub struct Impedance {
+pub struct ImpedanceOutput {
     pub magnitude: f32,
     pub phase: f32,
 }
 
+#[derive(Clone, Copy, Serialize, Deserialize, Schema, Debug, PartialEq)]
+pub enum IcdDftNum {
+    Num4,
+    Num8,
+    Num16,
+    Num32,
+    Num64,
+    Num128,
+    Num256,
+    Num512,
+    Num1024,
+    Num2048,
+    Num4096,
+    Num8192,
+    Num16384,
+}
+
 #[derive(Serialize, Deserialize, Schema, Debug, PartialEq)]
 pub struct StartImpedance {
     pub update_frequency: u32,
-    pub sinus_frequency: f32,
+    pub sinus_frequency: u32,
+    pub dft_number: IcdDftNum,
 }