diff --git a/src/drawApp/graphics/TrainInteraction.ts b/src/drawApp/graphics/TrainInteraction.ts
index d3d798c..1e0c3fc 100644
--- a/src/drawApp/graphics/TrainInteraction.ts
+++ b/src/drawApp/graphics/TrainInteraction.ts
@@ -607,25 +607,25 @@ export class TrainState extends GraphicStateBase implements ITrainState {
     this.states.tailOffset = v;
   }
   get dataSerialNumber(): number {
-    return this.states.btmState.dataSerialNumber;
+    return this.states.btmState?.dataSerialNumber;
   }
   set dataSerialNumber(v: number) {
     this.states.btmState.dataSerialNumber = v;
   }
   get baliseCount(): number {
-    return this.states.btmState.baliseCount;
+    return this.states.btmState?.baliseCount;
   }
   set baliseCount(v: number) {
     this.states.btmState.baliseCount = v;
   }
   get messageCounter(): number {
-    return this.states.btmState.messageCounter;
+    return this.states.btmState?.messageCounter;
   }
   set messageCounter(v: number) {
     this.states.btmState.messageCounter = v;
   }
   get telegram(): string {
-    return this.states.btmState.telegram;
+    return this.states.btmState?.telegram;
   }
   set telegram(v: string) {
     this.states.btmState.telegram = v;